iMechanica - Computational Mechanics Forum
https://imechanica.org/taxonomy/term/357
enInstalling Code-Aster Salome Meca
https://imechanica.org/node/25998
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>I would like to try Code Aster or Salome Meca FEM on MS-Windows. The problem for me is that I can't find a document that gives an overview of what each part does. </p>
<p>I am used to ABAQUS that comes together with "CAE" for creating input files and visualising the results from an "Output DataBase" (ODB). I have used the ABAQUS solver separate from CAE for some problems that it cannot create (I used Matlab to write the input file) so have no problem with the idea that different bits of code do different things.</p>
<p>There's a website <a href="https://code-aster-windows.com/" target="_blank" rel="noopener noreferrer">Code_Aster for Windows</a> (<a href="https://code-aster-windows.com/">https://code-aster-windows.com/</a>) that seems likely to be helpful, but again no straight forward explanation of what goes with what - it seems to be written for an audience that already know the system. It seems to have downloads for Salome and Code Aster - I can't tell if one part or both are needed. In some parts it says Code-Aster is included with Salome-Meca but on the Download page it says the .msi (Code_Aster) installation is needed in addition.</p>
<p>As a first application I would like to do contact mechanics modelling, including 2D (Plane strain) models.</p>
<p>It probably needs just a few paragraphs to make it clear - can anyone here provide them.</p>
<p>Regards,</p>
<p>Robert </p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/962">software</a></div></div></div>Sat, 28 May 2022 23:37:43 +0000Robert Paynter25998 at https://imechanica.orghttps://imechanica.org/node/25998#commentshttps://imechanica.org/crss/node/25998####
https://imechanica.org/node/25562
<div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/128">education</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/13307">25TL</a></div></div></div>Wed, 10 Nov 2021 13:48:22 +0000Affocky25562 at https://imechanica.orghttps://imechanica.org/node/25562#commentshttps://imechanica.org/crss/node/25562Almost incompressible hyperelastic theory
https://imechanica.org/node/25101
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><span>In Abaqus, when the material response is almost incompressible, Abaqus/Standard offers a “mixed” formulation.</span></p>
<p><img src="https://r1132100503382-eu1-3dswym.3dexperience.3ds.com/api/media/streammedia/id/Kln7ZiJATcSVXo2fHFjzRw/type/picture/key/o1/update/6619b8d82a3a64fe89df891cf8c6e4b9" /></p>
<p><span>I think this formulation is the three-field variational principle originally proposed by SlMO known as the mixed Jacobian-pressure formulation which emanates from a three-field variational principle of Hu and WASHIZU. The three independent field variables are displacement<em><strong> U</strong></em>, pressure <em><strong>P</strong></em> and volume dilatation<em><strong> J</strong></em>, respectively. But, In the derivation process in Abaqus, variations of Lagrange multiplier contains</span></p>
<p><img src="https://r1132100503382-eu1-3dswym.3dexperience.3ds.com/api/media/streammedia/id/pKF2OxfcSiWES8kOPqiheQ/type/picture/key/o1/update/0dbfb3c613930bf0337efee719fbfd60" /></p>
<p><span>which means P and J are not independently.</span></p>
<p><span> I want to know what exactly the variational principle Abaqus use and what are the independent field variables in the formulation.</span></p>
<p><img src="https://r1132100503382-eu1-3dswym.3dexperience.3ds.com/api/media/streammedia/id/vt34kgWTQTWHr3Nn0z2oQg/type/picture/key/o1/update/0379443216c2a96c46c1550f10421576" /></p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/3759">hyperelastic</a></div></div></div>Fri, 09 Apr 2021 03:47:20 +0000zhnanli25101 at https://imechanica.orghttps://imechanica.org/node/25101#commentshttps://imechanica.org/crss/node/25101Kinematic hardening analysis of Li-ion battery with concentration-dependent material behaviours under cyclic charging
https://imechanica.org/node/24109
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><span class="title-text">Kinematic hardening analysis of Li-ion battery with concentration-dependent material behaviours under cyclic charging and discharging</span></p>
<p><a id="bau1" class="author size-m workspace-trigger" href="https://www.sciencedirect.com/science/article/abs/pii/S0378775320304584#!" name="bau1"><span class="content"><span class="text given-name">A.</span><span class="text surname">Karami</span></span></a><span class="content"><a class="author size-m workspace-trigger" href="https://www.sciencedirect.com/science/article/abs/pii/S0378775320304584#!"><span class="text given-name">A.</span><span class="text surname">Nayebi</span></a>, </span><a class="doi" title="Persistent link using digital object identifier" href="https://doi.org/10.1016/j.jpowsour.2020.228155" target="_blank" rel="noopener noreferrer">https://doi.org/10.1016/j.jpowsour.2020.228155</a>Highlights</p>
<p id="abspara0015"> </p>
<dl class="list"><dt class="list-label">•</dt>
<dd class="list-description">
<p id="p0010">The diffusion equation with the variable coefficient is solved numerically.</p>
</dd>
<dt class="list-label">•</dt>
<dd class="list-description">
<p id="p0015">Choboche's nonlinear kinematic hardening model is used to study cyclic loading.</p>
</dd>
<dt class="list-label">•</dt>
<dd class="list-description">
<p id="p0020">Mechanical properties of the electrode are concentration-dependent in the analysis.</p>
</dd>
<dt class="list-label">•</dt>
<dd class="list-description">
<p id="p0025">The answer of the electrode under cyclic loading (shakedown-ratcheting) is studied.</p>
</dd>
<dt class="list-label">•</dt>
<dd class="list-description">
<p id="p0030">The effect of thickness ratio on the maximum stress in the electrode is studied. </p>
<p>Variation of stress and deformation in Li-ion batteries with a bilayer anode structure is studied in this research. Material properties vary due to the lithiation and delithiation. This important effect is considered in the modelling of elastic and plastic deformation. The diffusion equation with the variable coefficient is solved numerically, and the effect of the variable diffusion coefficient is investigated. Mechanical properties of the silicon, as a function of the lithium concentration, are characterized by using the available experimental and the molecular dynamics simulations results. Stress and deformation variation across the thickness and during the charging-discharging operations are obtained by using variable mechanical properties and Chaboche's nonlinear kinematic hardening model. Numerical results compare well with the experimental results, and it is elucidated that considering plastic deformation has a significant influence on the battery deformation and stress distribution. The cyclic loading answer of the electrodes is also studied. Shakedown or ratcheting answers can occur. Finally, it is shown that the thickness ratio of the electrode layers has an essential effect on the maximum stress and deformation in the bilayer electrode.</p>
</dd>
</dl><p> </p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div>Wed, 15 Apr 2020 14:30:55 +0000Nayebi24109 at https://imechanica.orghttps://imechanica.org/node/24109#commentshttps://imechanica.org/crss/node/24109Validation of 3D nonlinear elastic model- INCS method
https://imechanica.org/node/23925
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Dear Friends/ Researchers,</p>
<p>I work as a Ph.D. researcher at TU-Delft, Netherlands and I am modeling nonlinear propagation of 3D elastic waves (Compressional and Shear waves) in the nonlinear elastic medium using the INCS method (please check the attached image showing equations). The ultimate aim of this model is to simulate the 3D compressional and shear displacements, evaluate the displacement fields, the nonlinear force terms (appears in RHS of nonlinear elastic wave equation) and capture the generation of higher harmonics by iteratively solving integral equations for wavefield. We have some preliminary numerical results and we are looking for the possible options to validate our 3D numerical model. </p>
<p>In this scenario, we are also open to <strong>collaboration with an external group to validate our model either numerically (using the FEM model or COMSOL or ABAQUS tool) or experimentally</strong>. <span>And if possible, we can publish a journal paper together in this work. </span></p>
<p>I am also wondering if there are any 3D- analytical solutions available or can be derived for the above-mentioned case. </p>
<p>Any suggestions/ideas would be much appreciable. Thanks in advance. </p>
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</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/2882">Continuum mechanics; nonlinear elasticity</a></div><div class="field-item odd"><a href="/taxonomy/term/12742">3D elastic model</a></div></div></div>Wed, 22 Jan 2020 18:08:34 +0000Sundaraelangovan selvam23925 at https://imechanica.orghttps://imechanica.org/node/23925#commentshttps://imechanica.org/crss/node/23925Abaqus Explicit: difference in TEMP, STRESS and PEEQ computation between adiabatic and coupled
https://imechanica.org/node/23810
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Hi,</p>
<p>I have the two following INP files for Abaqus where the only difference is that in one case I'm using a CAX4R element on the other case, I'm using a CAX4RT element. Solver has been changed from one case to the other one.<br />
This is the only difference between both cases.</p>
<p>Simulation time is small, so that conduction is negligible.</p>
<p>BUT: results in terms of Strains, Stresses and Temperatures differs.<br />
T = 164.1°C for CX4R<br />
T = 323.9°C for CAX4RT</p>
<p>The difference is Huge, what's Wrong ?</p>
<p>Olivier</p>
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<tr class="odd"><td><span class="file"><img class="file-icon" alt="Plain text icon" title="text/plain" src="/modules/file/icons/text-plain.png" /> <a href="https://imechanica.org/files/Radial.inp_.txt" type="text/plain; length=2718">Radial.inp_.txt</a></span></td><td>2.65 KB</td> </tr>
<tr class="even"><td><span class="file"><img class="file-icon" alt="Plain text icon" title="text/plain" src="/modules/file/icons/text-plain.png" /> <a href="https://imechanica.org/files/RadialT.inp_.txt" type="text/plain; length=2733">RadialT.inp_.txt</a></span></td><td>2.67 KB</td> </tr>
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</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/289">ABAQUS</a></div><div class="field-item odd"><a href="/taxonomy/term/2567">Abaqus VUMAT Plasticity Adiabatic temperature</a></div></div></div>Fri, 06 Dec 2019 13:55:36 +0000Olivier Pantalé23810 at https://imechanica.orghttps://imechanica.org/node/23810#commentshttps://imechanica.org/crss/node/23810How do I count Keyword Blocks in the Abaqus input file?
https://imechanica.org/node/23724
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>The Abaqus documentation, available here:</p>
<p><a href="https://abaqus-docs.mit.edu/2017/English/SIMACAEMODRefMap/simamod-c-inputsyntax.htm">https://abaqus-docs.mit.edu/2017/English/SIMACAEMODRefMap/simamod-c-inpu...</a></p>
<p>states the following:</p>
<p>Certain keywords must be used in conjunction with other keywords; forexample, the *ELASTIC and *DENSITY keywords must be used in conjunction with the *MATERIAL keyword. These related keywords must be grouped in a block in the input file; unrelated keywords cannot be specified within this block. </p>
<p>But, on an existing .inp file, how do I recognize the blocks? </p>
<p>I need to count them to use that number as input to the KeywordBlock object in CAE so that CAE will insert a KeywordBlock into the .inp file at the appropriate place (the appropriate place I know, but not its number).</p>
<p>Information about the KeywordBlock object is found here:</p>
<p><a href="https://classes.engineering.wustl.edu/2009/spring/mase5513/abaqus/docs/v6.5/books/ker/default.htm?startat=pt01ch29pyo02.html">https://classes.engineering.wustl.edu/2009/spring/mase5513/abaqus/docs/v...</a></p>
<p>where they state:</p>
<p>Required Arguments. Position. An "Int" specifying the "position" of the keyword block after which the new block should be inserted.</p>
<p>So you see, I need to provide that number (the position), but just looking at the .inp file, I do not know how to recognize the blocks and thus I am unable to "count" them.</p>
<p>I have attached and input file (please change the extension to .inp). </p>
<p>I need to find the number of the *Buckle BLOCK (line 173). Thank you!</p>
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<tr class="odd"><td><span class="file"><img class="file-icon" alt="Plain text icon" title="text/plain" src="/modules/file/icons/text-plain.png" /> <a href="https://imechanica.org/files/2BarFrame.inp_.txt" type="text/plain; length=5104" title="2BarFrame.inp_.txt">sample .inp file (please change the extension to .inp)</a></span></td><td>4.98 KB</td> </tr>
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</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/962">software</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/11451">#ABAQUS</a></div><div class="field-item odd"><a href="/taxonomy/term/289">ABAQUS</a></div><div class="field-item even"><a href="/taxonomy/term/8249">*.inp files</a></div><div class="field-item odd"><a href="/taxonomy/term/8332">input file ABAQUS</a></div><div class="field-item even"><a href="/taxonomy/term/9140">abaqus keywords</a></div></div></div>Fri, 01 Nov 2019 14:48:21 +0000ebarbero23724 at https://imechanica.orghttps://imechanica.org/node/23724#commentshttps://imechanica.org/crss/node/23724Does anyone know how ABAQUS calculate ALLCD (viscoelastic energy dissipation)
https://imechanica.org/node/23701
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Hi, </p>
<p>I am doing some study with viscoelastic energy dissipation. I have a basic question for ABAQUS. </p>
<p>In ABAQUS, I notice there is a function to calculate Energy dissipated by creep, swelling, and viscoelasticity (ALLCD). You are able to plot energy change with time. </p>
<p>But want to know how ABAQUS calculates energy dissipation with time? What equation does it use?</p>
<p>I checked the textbook, when you need to calculate energy dissipation, you need to have at least one complete loading and unloading cycle. Then you use the integration area of loading/unloading curve to calculate energy. If the cycle is not completed, how do you calculate the energy? What is the equation to be used? </p>
<p>Thank you advance for any answer or ideas.</p>
<p> </p>
<p> </p>
<p> </p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/1482">Viscoelastic</a></div><div class="field-item odd"><a href="/taxonomy/term/678">Energy dissipation</a></div></div></div>Tue, 22 Oct 2019 17:48:58 +0000vincentc1723701 at https://imechanica.orghttps://imechanica.org/node/23701#commentshttps://imechanica.org/crss/node/23701Presentation of Cast2cloud, a web-based platform for mechanical and thermal simulations
https://imechanica.org/node/22881
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p dir="ltr"><span>Dear iMechanica</span><span>,</span></p>
<p dir="ltr"><span>We are pleased to present Cast2cloud (<a href="http://cast2cloud.com">http://cast2cloud.com</a>), the first and only web-based platform for interacting with Cast3M. The latter is a finite element software developed by the French Alternative Energies and Atomic Energy Commission (CEA) for mechanical and thermal simulations. It is available free of charge for teaching and research. For further information, please refer to </span><a href="http://www-cast3m.cea.fr/"><span>http://www-cast3m.cea.fr/</span></a><span>.</span></p>
<p><span>Cast2cloud is a non-profit project aiming to assist novice users of Cast3M and/or those who are less familiar with programming.</span></p>
<p dir="ltr"><span>Main features of Cast2cloud:</span></p>
<ul><li dir="ltr">
<p dir="ltr"><span>Create meshes using Cast3M for basic geometries like circles, rectangles, cylinders, etc.</span></p>
</li>
<li dir="ltr">
<p dir="ltr"><span>Handle meshes imported from external mesh generators</span></p>
</li>
<li dir="ltr">
<p dir="ltr"><span>Setup problems from many physical models and a wide range of materials</span></p>
</li>
<li dir="ltr">
<p dir="ltr"><span>Run simulations via the web browser by using the Cast2cloud computing server or custom servers of users (via SSH connection)</span></p>
</li>
<li dir="ltr">
<p dir="ltr"><span>Visualize simulation results directly on the web browser</span></p>
</li>
</ul><p dir="ltr"><span>Any feedback is welcome, please send us via:</span></p>
<ul><li dir="ltr">
<p dir="ltr"><span>Mail: <a href="mailto:contact@cast2cloud.com">contact@cast2cloud.com</a></span></p>
</li>
<li dir="ltr">
<p dir="ltr"><span>Feedback button on cast2cloud.com</span></p>
</li>
</ul><p dir="ltr"><span>For more information, please have a look on the Cast2cloud overview video:</span><span><a href="https://www.youtube.com/watch?v=BtXcAewwI5Y">https://www.youtube.com/watch?v=BtXcAewwI5Y</a></span></p>
<p dir="ltr"><span>Kind regards,</span></p>
<p dir="ltr"><span>Team Cast2cloud</span></p>
<p><span> </span></p>
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</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/962">software</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/12312"># Finite Element modeling; # Cloud computing: # Cast2cloud; # Cast3m;</a></div></div></div>Wed, 21 Nov 2018 06:30:50 +0000hieppt22881 at https://imechanica.orghttps://imechanica.org/node/22881#commentshttps://imechanica.org/crss/node/22881Johnson Cook model - flow stress match with UTS at ductility?
https://imechanica.org/node/22873
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><span>Hi, </span></p>
<p><span>I am trying to use Johnson Cook model for predicting equivalent flow stress. Just to check its validity at extremes, I used ductility as plastic strain, but I don't see it output stress close to ultimate tensile strength. I used plastic strain rate of 1.5% per min as specified for ultimate tensile test in ISO standard. Room temperature considered. All other parameters like A, B, C, n - I have taken from standard available literature. Is it not necessary for equivalent flow stress to match with ultimate tensile strength as plastic strain equals ductility? If so, how can we believe flow stress obtained between yield and ultimate? Please comment.</span></p>
<p>Thank you.</p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/4956">Johnson Cook Model</a></div></div></div>Sun, 18 Nov 2018 04:04:45 +0000KolluruK22873 at https://imechanica.orghttps://imechanica.org/node/22873#commentshttps://imechanica.org/crss/node/22873FEA Position at BD Working on the Next Generation of Medical Devices
https://imechanica.org/node/22381
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>BD is one of the largest global medical technology companies in the world and is advancing the world of health by improving medical discovery, diagnostics, and the delivery of care. The BD Corporate CAE group, located near Raleigh, NC, is hiring an Engineer II focused on nonlinear structural mechanics, primarily using Abaqus. The Corporate CAE group is BD's modeling and simulation Center of Excellence, and is rapidly growing to accomodate need from across BD's large portfolio of products. The person hired to this position will have the opportunity to contribute to the advancement of BD’s next generation medical products and enhance the current product portfolio. Applicants should have experience using nonlinear FEA and a minimum of a B.S. in Mechanical Engineering or similar field. If interested, please apply at the link below.</p>
<p><span><a href="https://jobs.bd.com/job/research-triangle-park/engineer-ii/159/8191942">https://jobs.bd.com/job/research-triangle-park/engineer-ii/159/8191942</a></span></p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/73">job</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/289">ABAQUS</a></div><div class="field-item odd"><a href="/taxonomy/term/12074">industry job</a></div><div class="field-item even"><a href="/taxonomy/term/3969">medical devices</a></div><div class="field-item odd"><a href="/taxonomy/term/4405">biomedical devices and biomechanics</a></div></div></div>Fri, 25 May 2018 11:53:12 +0000Marcus Rademacher22381 at https://imechanica.orghttps://imechanica.org/node/22381#commentshttps://imechanica.org/crss/node/22381Mixed mode cohesive zone model formulation in Abaqus
https://imechanica.org/node/22232
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>I am having some difficulty understanding the particulars of the implementation of Abaqus' cohesive zone model (CZM). I also see some differences in what is available in the Abaqus User's Guide (Section 32.5.6) and what is reported for Abaqus' CZM in highly regarded academic literature. </p>
<p>(A) I understand that there have been some discrepancies between LEFM predictions and Abaqus' CZM under mixed mode loading conditions due to path dependence of the loading history, as reported by [1,2]. As far as I understand, this issue was addressed by implementing a default non-accumulated energy measure for the definition of the mode mix ratio, such that the new definition relies only on the current deformation state, and not on the history of the deformation, in order to achieve better alignment with LEFM predictions. This is reported in [7], although, for some reason, the non-accumulated energy measure of the mode mix ratio is not discussed as extensively in the Abaqus User's Guide. </p>
<p>(B) Other sources highlight that due to the coupled, mixed-mode formulation of Abaqus' CZM, it suffers from inaccurate energy dissipation when the pure mode I fracture toughness and the pure mode II toughness are set to different values. There is also inaccuracy when the normal and tangential cohesive strengths or the initial elastic stiffnesses are unequal. This can result in “restoration of the cohesive state” under changing mode-mixity, after an element has failed, and has been highlighted in [2,3,4,5]. Turon et al. [5] proposed a modification to the CZM formulation but it requires the normal and shear cohesive strengths to be set at a certain ratio to ensure correct energy dissipation under changing mode-mixity. </p>
<p>(C) Campilho et al. [6] report on the use of Abaqus' CZM in an uncoupled, mixed-mode manner, such that: the initiation of damage is coupled between tension and shear through the quadratic stress criterion, but upon the initiation of damage an uncoupled tensile/shear behaviour was used, in which the tensile and shear behaviours of the CZM elements are independent up to failure. This constitutes the use of two separate damage variables, one for tension and one for shear, to degrade the material stiffness in each respective direction. However, they present contour plots of a single damage variable (SDEG). Additionally, Abaqus User's Guide (Section 32.5.6) states under the heading “Evaluating damage when multiple criteria are active”, that “when multiple damage initiation criteria and associated evolution definitions are used for the same material, each evolution definition results in its own damage variable”. However, it is not possible to specify separate damage evolution criteria based on one quadratic stress damage initiation criterion, and similarly, it is not possible to specify two quadratic stress damage initiation criterion under the one material. Thus, I cannot see how Campilho et al. [6] are able to determine the use of two separate damage variables, one for tension and one for shear. Their description of Abaqus' CZM also negates the use of the “effective displacement” to define material damage based on mixed mode loading, as defined in the Abaqus User's Guide (Section 32.5.6). </p>
<p>My questions are: <br />1. Are (A) and (B) one of the same issue? Has this been rectified through the non-accumulated energy measure for the definition of the mode mix ratio? <br />2. Can the CZM formulation described in [6] actually be achieved in Abaqus? If so, what does the damage variable (SDEG) represent in this case? It would also make sense that this formulation would not be subject to (A) and (B), is this correct? </p>
<p>References <br />[1] Song, K., Dávila, C.G. and Rose, C.A., 2008, May. Guidelines and parameter selection for the simulation of progressive delamination. In ABAQUS User’s Conference (Vol. 41, pp. 43-44). <br />[2] Sarrado, C., Turon, A., Renart, J. and Urresti, I., 2012. Assessment of energy dissipation during mixed-mode delamination growth using cohesive zone models. Composites Part A: Applied Science and Manufacturing, 43(11), pp.2128-2136. <br />[3] Goutianos, S. and Sørensen, B.F., 2012. Path dependence of truss-like mixed mode cohesive laws. Engineering Fracture Mechanics, 91, pp.117-132. <br />[4] Turon, A., Camanho, P.P., Costa, J. and Dávila, C.G., 2006. A damage model for the simulation of delamination in advanced composites under variable-mode loading. Mechanics of Materials, 38(11), pp.1072-1089. <br />[5] Turon, A., Camanho, P.P., Costa, J. and Renart, J., 2010. Accurate simulation of delamination growth under mixed-mode loading using cohesive elements: definition of interlaminar strengths and elastic stiffness. Composite structures, 92(8), pp.1857-1864. <br />[6] Campilho, R.D., Banea, M.D., Neto, J.A.B.P. and da Silva, L.F., 2013. Modelling adhesive joints with cohesive zone models: effect of the cohesive law shape of the adhesive layer. International Journal of Adhesion and Adhesives, 44, pp.48-56. <br />[7] Bose, K., Hurtado, J., Krishna, S., and Xia, L., 2013, July. Validation of cohesive-zone based mixed-mode formulations in Abaqus. U.S. National Congress on Computational Mechanics, Raleigh, NC.</p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/2166">ABAQUS Cohesive Elements</a></div></div></div>Wed, 14 Mar 2018 13:07:57 +0000michael.corbett22232 at https://imechanica.orghttps://imechanica.org/node/22232#commentshttps://imechanica.org/crss/node/22232Сооружение Зданий
https://imechanica.org/node/22158
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Строительство Объектов - это сложная и трудоемкая задача, с которой невозможно справиться без должной подготовки, знаний, опыта и специального оборудования. Любые ошибки, допущенные при разработке проекта и возведении дома, в дальнейшем приведут к серьезным неприятностям: проседанию фундамента, возникновению перекосов и трещин, ухудшению теплоизоляции и др. Чтобы не допустить подобных проблем, следует обращаться за помощью к профессионалам, ели заинтересовались<br /><a href="http://les54.ru/yetapy-stroitelstva"></a>Построить дом Уникальная предварительная обработка древесины — это залог качества будущего дома и его долговечности. Безусловно, наши предки были великими мастерами, однако даже им сложно было добиться идеальной поверхности стен, ведь обычный топор не мог предоставить подобных возможностей.</p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/74">conference</a></div></div></div>Thu, 22 Feb 2018 15:44:27 +0000Les22158 at https://imechanica.orghttps://imechanica.org/node/22158#commentshttps://imechanica.org/crss/node/22158Validation of Numerical (INCS) method for Elastic wave case
https://imechanica.org/node/22013
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Dear mechanician,</p>
<p>I am a Ph.D. in TU-Delft, working on modeling of Nonlinear Elastodynamic waves. I have finished the 1-D numerical model of the Nonlinear Elastic equation using INCS (Iterative Nonlinear Contrast Source) method. Now, I am working on the validation of the numerical method. Firstly, we are doing some experimental verifications to validate my numerical results. In parallel, I am aware (and told) that I can also validate my numerical method using a benchmark solution (analytical solution), i.e. Burger's equation. But I never worked on the Burger's equation before and when I <span>have gone </span>through it on Internet, it was pretty much confusing to me because Burger's equation is available for the Fluid mechanics and comparing it with the nonlinear Elastic equation is unclear to me. </p>
<p>Do anyone worked on the Burger's equation before? Or any references would be helpful. Also, if you have any other suggestions in regard to validation using other methods would be much appreciable. Kindly looking forward to your help.</p>
<p>Have a nice day, good luck.</p>
<p>Best regards,</p>
<p> </p>
<p>Elango. </p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/481">Nonlinear elasticity</a></div></div></div>Tue, 09 Jan 2018 14:27:32 +0000Sundaraelangovan selvam22013 at https://imechanica.orghttps://imechanica.org/node/22013#commentshttps://imechanica.org/crss/node/22013Regarding to the effective elastic tensor form of a double layered perforation panel
https://imechanica.org/node/21964
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p align="left"><span><span><span lang="EN-GB" xml:lang="EN-GB">I am studying the effective material property of a double-layered perforation </span><span lang="EN-US" xml:lang="EN-US">(Fig. 1). The perforation rate is different on the two layers, which are connected via arrays of pillars. Both perforation and pillars are closer packed in y-direction (the beam length direction) than the x-direction (the beam width direction) to render an anisotropic in plane material property. Fig. 1 (b) shows a unit cell of such a periodic perforation.</span></span></span></p>
<p align="left"><span><span><span lang="EN-US" xml:lang="EN-US"><span><span><span lang="EN-GB" xml:lang="EN-GB"><span><span><span><span lang="EN-GB" xml:lang="EN-GB"><span><img src="https://sites.google.com/site/shenzhiyuanspiezomemoirs/_/rsrc/1513872854356/effective-elastic-property-of-perforation/1b.png" alt="" border="0" /><img src="https://sites.google.com/site/shenzhiyuanspiezomemoirs/_/rsrc/1513872858139/effective-elastic-property-of-perforation/1c.png" alt="" border="0" /></span></span></span></span></span></span></span></span></span></span></span></p>
<p align="left"><span><span><span lang="EN-US" xml:lang="EN-US"><span><span><span lang="EN-GB" xml:lang="EN-GB"><span><span><span><span lang="EN-GB" xml:lang="EN-GB"><span> </span></span></span></span></span></span></span></span></span></span></span></p>
<p><span lang="EN-GB" xml:lang="EN-GB"><span><span><span> </span></span><span>(a)</span><span><span> </span></span><span>(b)</span></span></span></p>
<p><span lang="EN-GB" xml:lang="EN-GB"><span>Fig. 1, (a) a double-layered perforation (b) the unit cell of the double-layered perforation.</span></span></p>
<p><span lang="EN-GB" xml:lang="EN-GB"><span> </span></span></p>
<p><span lang="EN-US" xml:lang="EN-US"><span>The effective material property of a single layer perforation is well established. Its orthotropic symmetry has rendered the effective compliance matrix to have the form in Fig. 2 (b). </span></span></p>
<p> </p>
<p><span lang="EN-US" xml:lang="EN-US"><span><img src="https://sites.google.com/site/shenzhiyuanspiezomemoirs/_/rsrc/1513872862549/effective-elastic-property-of-perforation/2a.png" alt="" border="0" /><img src="https://sites.google.com/site/shenzhiyuanspiezomemoirs/_/rsrc/1513872866037/effective-elastic-property-of-perforation/2c.png" alt="" border="0" /></span></span></p>
<p><span lang="EN-US" xml:lang="EN-US"><span> </span></span></p>
<p><span lang="EN-US" xml:lang="EN-US"><span><span>(a)<span> </span></span><span>(b)</span></span></span></p>
<p><span lang="EN-US" xml:lang="EN-US"><span>Fig. 2, (a) a unit cell of a single layer perforation. (b) effective compliance matrix for the single layer perforation.</span></span></p>
<p><span lang="EN-US" xml:lang="EN-US"><span> </span></span></p>
<p><span lang="EN-US" xml:lang="EN-US"><span>Although the symmetry of the double-layered perforation (point group 2mm) is slightly different from the single perforation symmetry (point group mmm), they both belongs to the orthohombic class. My question is: can the double-layered perforation be equivalented to be a homogeneous anisotropic material with the compliance matrix in Fig. 2 (b)? Is the fact that the perforation gets only one period in the thickness direction makes the effective elastic tensor form different? What will be the form? </span></span></p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div>Thu, 21 Dec 2017 16:18:39 +0000SHEN Zhiyuan21964 at https://imechanica.orghttps://imechanica.org/node/21964#commentshttps://imechanica.org/crss/node/21964Regarding to use the effective Kirshhoff plate property to model a microbeam
https://imechanica.org/node/21963
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p align="left"><span lang="EN-GB" xml:lang="EN-GB">I am studying the vibrational behaviour of a microbeam made of a polymer (</span><span lang="EN-GB" xml:lang="EN-GB"><span>Fig. 1). The beam consists of a paddle part and a tapered part and is fixed at the tapered end. </span></span></p>
<p align="left"> </p>
<p align="left"><span lang="EN-GB" xml:lang="EN-GB"><span> <img src="https://sites.google.com/site/shenzhiyuanspiezomemoirs/_/rsrc/1513870519966/effective-elastic-property-of-perforation/1a.png" alt="" border="0" /></span></span></p>
<p align="left"> </p>
<p align="left"><span lang="EN-GB" xml:lang="EN-GB"><span>Fig. 1, a microbeam model.</span></span></p>
<p align="left"> </p>
<p><span lang="EN-GB" xml:lang="EN-GB"><span>The thickness/side length ratio in the paddle part is 1/25 (width= 100 micrometre; thickness = 4 micrometer) so the paddle part can be treated as a Kirchhoff plate. The width of the beam, however, gradually tapers to 10 micrometer at its clamped end. Can I treat the whole microbeam as a Kirshhoff plate and use the effective Kirshhoff plate model to predict the vibrational frequencies and mode shape of this microbeam? Will the tapering make the structure invalid to be treated as a Kirchhoff plate? Is there other effective plate model better suited for this microbeam? </span></span></p>
<p><span lang="EN-US" xml:lang="EN-US"><span> </span></span></p>
<p><span lang="EN-US" xml:lang="EN-US"><span>The fabricated micro-beam in fact got curvature due to processing residue stress. Can the effective Kirshhoff plate flexibility tensor be assigned to a curved shell in a COMSOL model? Will the shell model with the correct curvature together with the effective Kirshhoff plate flexibility tensor be enough to predict the vibrational behavior of the microbeam?</span></span></p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/11888">Kirshhoff plate</a></div><div class="field-item odd"><a href="/taxonomy/term/11889">microbeam</a></div><div class="field-item even"><a href="/taxonomy/term/5240">vibrational</a></div></div></div>Thu, 21 Dec 2017 15:53:12 +0000SHEN Zhiyuan21963 at https://imechanica.orghttps://imechanica.org/node/21963#commentshttps://imechanica.org/crss/node/21963Regarding to the effective elastic property of a double-layered perforation
https://imechanica.org/node/21941
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p align="left"><span lang="EN-GB" xml:lang="EN-GB"><span>Dear Friends, Attached please find a doc describing the problem. Any feed back is welcome. Thanks!</span></span></p>
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<tr class="odd"><td><span class="file"><img class="file-icon" alt="PDF icon" title="application/pdf" src="/modules/file/icons/application-pdf.png" /> <a href="https://imechanica.org/files/The%20effective%20elastic%20material%20property%20of%20a%20double%20layered%20peroration.doc.pdf" type="application/pdf; length=618420">The effective elastic material property of a double layered peroration.doc.pdf</a></span></td><td>603.93 KB</td> </tr>
<tr class="even"><td><span class="file"><img class="file-icon" alt="PDF icon" title="application/pdf" src="/modules/file/icons/application-pdf.png" /> <a href="https://imechanica.org/files/Equivalent%20models%20of%20corrugated%20panels_0.pdf" type="application/pdf; length=1042707">Equivalent models of corrugated panels.pdf</a></span></td><td>1018.27 KB</td> </tr>
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</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/11881">perforation effective tensor vibration microbeam</a></div></div></div>Wed, 13 Dec 2017 17:13:33 +0000SHEN Zhiyuan21941 at https://imechanica.orghttps://imechanica.org/node/21941#commentshttps://imechanica.org/crss/node/21941Problem with defining corner BC/constraint
https://imechanica.org/node/21911
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Hello all,</p>
<p>I'm trying to model the buckling of a shell structure under thermal load.</p>
<p>The structure is square-shaped.</p>
<p>The left edge must be kept straight. To achieve that, I applied MPC Tie Constraint for its nodes.</p>
<p>The bottom edge must be fixed so that the BC applied at its nodes was U1 = U2 = U3 = 0.</p>
<p>Temperature is applied as a predefined field.</p>
<p>However, when I run the simulation the corner that connects both edges deforms very strangely which makes me question how to model it.</p>
<p>I appreciate any input. Thanks.</p>
<p>PS. I've attached a picture of the simulation result.</p>
</div></div></div><div class="field field-name-upload field-type-file field-label-hidden"><div class="field-items"><div class="field-item even"><table class="sticky-enabled">
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<tr class="odd"><td><span class="file"><img class="file-icon" alt="Image icon" title="image/png" src="/modules/file/icons/image-x-generic.png" /> <a href="https://imechanica.org/files/Picture_0_0.png" type="image/png; length=75033" title="Picture_0.png">Simulation Result</a></span></td><td>73.27 KB</td> </tr>
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</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/11451">#ABAQUS</a></div><div class="field-item odd"><a href="/taxonomy/term/9504">constraints</a></div><div class="field-item even"><a href="/taxonomy/term/11869">BCs</a></div></div></div>Mon, 04 Dec 2017 16:02:24 +0000frobles21911 at https://imechanica.orghttps://imechanica.org/node/21911#commentshttps://imechanica.org/crss/node/21911Tangent modulus of the Mooney-Rivlin based Neo-hookean - Could you check my derivation??
https://imechanica.org/node/21745
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Hello.</p>
<p> </p>
<p>I study solid mechanics at a graduate school.</p>
<p> </p>
<p>I tried to derive tangent modulus of the Mooney-Rivlin based Neo-Hookean material.</p>
<p> </p>
<p>There might be no error in my derivation, but answer is wrong with referred right answer.</p>
<p> </p>
<p>So, could you check my derivation?</p>
<p> </p>
<p>I attached my derivation as a figure.</p>
</div></div></div><div class="field field-name-upload field-type-file field-label-hidden"><div class="field-items"><div class="field-item even"><table class="sticky-enabled">
<thead><tr><th>Attachment</th><th>Size</th> </tr></thead>
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<tr class="odd"><td><span class="file"><img class="file-icon" alt="Image icon" title="image/png" src="/modules/file/icons/image-x-generic.png" /> <a href="https://imechanica.org/files/20171018%20Derivation%20of%20tangent%20modulus%20of%20Mooney-NH%20-%20Hobeom%20Kim_0.png" type="image/png; length=78922" title="20171018 Derivation of tangent modulus of Mooney-NH - Hobeom Kim.png">My derivation, please check it.</a></span></td><td>77.07 KB</td> </tr>
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</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/128">education</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/9442">Hyperelastic Materials</a></div><div class="field-item odd"><a href="/taxonomy/term/4819">Neo-Hookean</a></div><div class="field-item even"><a href="/taxonomy/term/6090">Mooney-Rivlin Model</a></div></div></div>Mon, 23 Oct 2017 09:17:30 +0000Hobeom Kim21745 at https://imechanica.orghttps://imechanica.org/node/21745#commentshttps://imechanica.org/crss/node/21745In 1D wave propagation problem, how to find the curl of a given source function?
https://imechanica.org/node/21709
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>I am trying to solve 1-D wave equation by calculating potentials <span id="MathJax-Element-1-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mi>&#x03D5;</mi><mspace width="thickmathspace" /><mi>a</mi><mi>n</mi><mi>d</mi><mspace width="mediummathspace" /><msub><mi>&#x03C8;</mi><mi>x</mi></msub></math>"><span id="MathJax-Span-1" class="math"><span><span><span id="MathJax-Span-2" class="mrow"><span id="MathJax-Span-3" class="mi">ϕ</span><span id="MathJax-Span-4" class="mspace"></span><span id="MathJax-Span-5" class="mi">a</span><span id="MathJax-Span-6" class="mi">n</span><span id="MathJax-Span-7" class="mi">d</span><span id="MathJax-Span-8" class="mspace"></span><span id="MathJax-Span-9" class="msubsup"><span><span><span id="MathJax-Span-10" class="mi">ψ</span></span><span><span id="MathJax-Span-11" class="mi">x</span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">ϕandψx</span></span> for displacement field <span id="MathJax-Element-2-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">u</mi><mi mathvariant="bold">x</mi></msub></mrow><mspace width="mediummathspace" /><mo>=</mo><mspace width="mediummathspace" /><mi mathvariant="normal">&#x2207;</mi><mi>&#x03D5;</mi><mspace width="mediummathspace" /><mo>+</mo><mspace width="mediummathspace" /><mi mathvariant="normal">&#x2207;</mi><mo>&#x00D7;</mo><mi>&#x03C8;</mi></math>"><span id="MathJax-Span-12" class="math"><span><span><span id="MathJax-Span-13" class="mrow"><span id="MathJax-Span-14" class="texatom"><span id="MathJax-Span-15" class="mrow"><span id="MathJax-Span-16" class="msubsup"><span><span><span id="MathJax-Span-17" class="mi">u</span></span><span><span id="MathJax-Span-18" class="mi">x</span></span></span></span></span></span><span id="MathJax-Span-19" class="mspace"></span><span id="MathJax-Span-20" class="mo">=</span><span id="MathJax-Span-21" class="mspace"></span><span id="MathJax-Span-22" class="mi">∇</span><span id="MathJax-Span-23" class="mi">ϕ</span><span id="MathJax-Span-24" class="mspace"></span><span id="MathJax-Span-25" class="mo">+</span><span id="MathJax-Span-26" class="mspace"></span><span id="MathJax-Span-27" class="mi">∇</span><span id="MathJax-Span-28" class="mo">×</span><span id="MathJax-Span-29" class="mi">ψ</span></span></span></span></span><span class="MJX_Assistive_MathML">ux=∇ϕ+∇×ψ</span></span>. I am trying to decompose my source function <span id="MathJax-Element-3-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">f</mi><mi mathvariant="bold">x</mi></msub></mrow></math>"><span id="MathJax-Span-30" class="math"><span><span><span id="MathJax-Span-31" class="mrow"><span id="MathJax-Span-32" class="texatom"><span id="MathJax-Span-33" class="mrow"><span id="MathJax-Span-34" class="msubsup"><span><span><span id="MathJax-Span-35" class="mi">f</span></span><span><span id="MathJax-Span-36" class="mi">x</span></span></span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">fx</span></span> (such that <span id="MathJax-Element-4-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">f</mi><mi mathvariant="bold">x</mi></msub></mrow><mo>=</mo><mspace width="mediummathspace" /><mi mathvariant="normal">&#x2207;</mi><mi>b</mi><mspace width="mediummathspace" /><mo>+</mo><mspace width="mediummathspace" /><mi mathvariant="normal">&#x2207;</mi><mo>&#x00D7;</mo><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">h</mi><mi mathvariant="bold">x</mi></msub></mrow></math>"><span id="MathJax-Span-37" class="math"><span><span><span id="MathJax-Span-38" class="mrow"><span id="MathJax-Span-39" class="texatom"><span id="MathJax-Span-40" class="mrow"><span id="MathJax-Span-41" class="msubsup"><span><span><span id="MathJax-Span-42" class="mi">f</span></span><span><span id="MathJax-Span-43" class="mi">x</span></span></span></span></span></span><span id="MathJax-Span-44" class="mo">=</span><span id="MathJax-Span-45" class="mspace"></span><span id="MathJax-Span-46" class="mi">∇</span><span id="MathJax-Span-47" class="mi">b</span><span id="MathJax-Span-48" class="mspace"></span><span id="MathJax-Span-49" class="mo">+</span><span id="MathJax-Span-50" class="mspace"></span><span id="MathJax-Span-51" class="mi">∇</span><span id="MathJax-Span-52" class="mo">×</span><span id="MathJax-Span-53" class="texatom"><span id="MathJax-Span-54" class="mrow"><span id="MathJax-Span-55" class="msubsup"><span><span><span id="MathJax-Span-56" class="mi">h</span></span><span><span id="MathJax-Span-57" class="mi">x</span></span></span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">fx=∇b+∇×hx</span></span>) in terms of potentials <span id="MathJax-Element-5-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mi>b</mi><mspace width="mediummathspace" /><mi>a</mi><mi>n</mi><mi>d</mi><mspace width="mediummathspace" /><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">h</mi><mi mathvariant="bold">x</mi></msub></mrow></math>"><span id="MathJax-Span-58" class="math"><span><span><span id="MathJax-Span-59" class="mrow"><span id="MathJax-Span-60" class="mi">b</span><span id="MathJax-Span-61" class="mspace"></span><span id="MathJax-Span-62" class="mi">a</span><span id="MathJax-Span-63" class="mi">n</span><span id="MathJax-Span-64" class="mi">d</span><span id="MathJax-Span-65" class="mspace"></span><span id="MathJax-Span-66" class="texatom"><span id="MathJax-Span-67" class="mrow"><span id="MathJax-Span-68" class="msubsup"><span><span><span id="MathJax-Span-69" class="mi">h</span></span><span><span id="MathJax-Span-70" class="mi">x</span></span></span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">bandhx</span></span>, using which I can can compute <span id="MathJax-Element-6-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mi>&#x03D5;</mi><mspace width="thickmathspace" /><mi>a</mi><mi>n</mi><mi>d</mi><mspace width="mediummathspace" /><msub><mi>&#x03C8;</mi><mi>x</mi></msub></math>"><span id="MathJax-Span-71" class="math"><span><span><span id="MathJax-Span-72" class="mrow"><span id="MathJax-Span-73" class="mi">ϕ</span><span id="MathJax-Span-74" class="mspace"></span><span id="MathJax-Span-75" class="mi">a</span><span id="MathJax-Span-76" class="mi">n</span><span id="MathJax-Span-77" class="mi">d</span><span id="MathJax-Span-78" class="mspace"></span><span id="MathJax-Span-79" class="msubsup"><span><span><span id="MathJax-Span-80" class="mi">ψ</span></span><span><span id="MathJax-Span-81" class="mi">x</span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">ϕandψx</span></span>. While decomposing source term <span id="MathJax-Element-7-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">f</mi><mi mathvariant="bold">x</mi></msub></mrow></math>"><span id="MathJax-Span-82" class="math"><span><span><span id="MathJax-Span-83" class="mrow"><span id="MathJax-Span-84" class="texatom"><span id="MathJax-Span-85" class="mrow"><span id="MathJax-Span-86" class="msubsup"><span><span><span id="MathJax-Span-87" class="mi">f</span></span><span><span id="MathJax-Span-88" class="mi">x</span></span></span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">fx</span></span>, trying to calculate <span id="MathJax-Element-8-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mi>b</mi><mspace width="mediummathspace" /><mi>a</mi><mi>n</mi><mi>d</mi><mspace width="mediummathspace" /><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">h</mi><mi mathvariant="bold">x</mi></msub></mrow></math>"><span id="MathJax-Span-89" class="math"><span><span><span id="MathJax-Span-90" class="mrow"><span id="MathJax-Span-91" class="mi">b</span><span id="MathJax-Span-92" class="mspace"></span><span id="MathJax-Span-93" class="mi">a</span><span id="MathJax-Span-94" class="mi">n</span><span id="MathJax-Span-95" class="mi">d</span><span id="MathJax-Span-96" class="mspace"></span><span id="MathJax-Span-97" class="texatom"><span id="MathJax-Span-98" class="mrow"><span id="MathJax-Span-99" class="msubsup"><span><span><span id="MathJax-Span-100" class="mi">h</span></span><span><span id="MathJax-Span-101" class="mi">x</span></span></span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">bandhx</span></span>, I have a problem/confusion in finding the <span id="MathJax-Element-9-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mi>c</mi><mi>u</mi><mi>r</mi><mi>l</mi></math>"><span id="MathJax-Span-102" class="math"><span><span><span id="MathJax-Span-103" class="mrow"><span id="MathJax-Span-104" class="mi">c</span><span id="MathJax-Span-105" class="mi">u</span><span id="MathJax-Span-106" class="mi">r</span><span id="MathJax-Span-107" class="mi">l</span></span></span></span></span><span class="MJX_Assistive_MathML">curl</span></span> of <span id="MathJax-Element-10-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">h</mi><mi mathvariant="bold">x</mi></msub></mrow></math>"><span id="MathJax-Span-108" class="math"><span><span><span id="MathJax-Span-109" class="mrow"><span id="MathJax-Span-110" class="texatom"><span id="MathJax-Span-111" class="mrow"><span id="MathJax-Span-112" class="msubsup"><span><span><span id="MathJax-Span-113" class="mi">h</span></span><span><span id="MathJax-Span-114" class="mi">x</span></span></span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">hx</span></span>. Please see the manual hand-written picture attached here </p>
<p>I am solving for <span id="MathJax-Element-11-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mrow class="MJX-TeXAtom-ORD"><mi mathvariant="bold">w</mi></mrow></math>"><span id="MathJax-Span-115" class="math"><span><span><span id="MathJax-Span-116" class="mrow"><span id="MathJax-Span-117" class="texatom"><span id="MathJax-Span-118" class="mrow"><span id="MathJax-Span-119" class="mi">w</span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">w</span></span> via the Poisson's equation <span id="MathJax-Element-12-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><msup><mi mathvariant="normal">&#x2207;</mi><mn>2</mn></msup><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">w</mi><mi mathvariant="bold">x</mi></msub></mrow><mo>=</mo><mspace width="mediummathspace" /><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">f</mi><mi mathvariant="bold">x</mi></msub></mrow></math>"><span id="MathJax-Span-120" class="math"><span><span><span id="MathJax-Span-121" class="mrow"><span id="MathJax-Span-122" class="msubsup"><span><span><span id="MathJax-Span-123" class="mi">∇</span></span><span><span id="MathJax-Span-124" class="mn">2</span></span></span></span><span id="MathJax-Span-125" class="texatom"><span id="MathJax-Span-126" class="mrow"><span id="MathJax-Span-127" class="msubsup"><span><span><span id="MathJax-Span-128" class="mi">w</span></span><span><span id="MathJax-Span-129" class="mi">x</span></span></span></span></span></span><span id="MathJax-Span-130" class="mo">=</span><span id="MathJax-Span-131" class="mspace"></span><span id="MathJax-Span-132" class="texatom"><span id="MathJax-Span-133" class="mrow"><span id="MathJax-Span-134" class="msubsup"><span><span><span id="MathJax-Span-135" class="mi">f</span></span><span><span id="MathJax-Span-136" class="mi">x</span></span></span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">∇2wx=fx</span></span>, in order to evaluate the potentials <span id="MathJax-Element-13-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mspace width="mediummathspace" /><mi>b</mi><mspace width="mediummathspace" /><mi>a</mi><mi>n</mi><mi>d</mi><mspace width="mediummathspace" /><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">h</mi><mi mathvariant="bold">x</mi></msub></mrow></math>"><span id="MathJax-Span-137" class="math"><span><span><span id="MathJax-Span-138" class="mrow"><span id="MathJax-Span-139" class="mspace"></span><span id="MathJax-Span-140" class="mi">b</span><span id="MathJax-Span-141" class="mspace"></span><span id="MathJax-Span-142" class="mi">a</span><span id="MathJax-Span-143" class="mi">n</span><span id="MathJax-Span-144" class="mi">d</span><span id="MathJax-Span-145" class="mspace"></span><span id="MathJax-Span-146" class="texatom"><span id="MathJax-Span-147" class="mrow"><span id="MathJax-Span-148" class="msubsup"><span><span><span id="MathJax-Span-149" class="mi">h</span></span><span><span id="MathJax-Span-150" class="mi">x</span></span></span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">bandhx</span></span>. So that the scalar potential <span id="MathJax-Element-14-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mspace width="mediummathspace" /><mi>b</mi><mo>=</mo><mspace width="mediummathspace" /><mi mathvariant="normal">&#x2207;</mi><mo>&#x22C5;</mo><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">w</mi><mi mathvariant="bold">x</mi></msub></mrow></math>"><span id="MathJax-Span-151" class="math"><span><span><span id="MathJax-Span-152" class="mrow"><span id="MathJax-Span-153" class="mspace"></span><span id="MathJax-Span-154" class="mi">b</span><span id="MathJax-Span-155" class="mo">=</span><span id="MathJax-Span-156" class="mspace"></span><span id="MathJax-Span-157" class="mi">∇</span><span id="MathJax-Span-158" class="mo">⋅</span><span id="MathJax-Span-159" class="texatom"><span id="MathJax-Span-160" class="mrow"><span id="MathJax-Span-161" class="msubsup"><span><span><span id="MathJax-Span-162" class="mi">w</span></span><span><span id="MathJax-Span-163" class="mi">x</span></span></span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">b=∇⋅wx</span></span> and vector potential <span id="MathJax-Element-15-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">h</mi><mi mathvariant="bold">x</mi></msub></mrow><mo>=</mo><mo>&#x2212;</mo><mi mathvariant="normal">&#x2207;</mi><mo>&#x00D7;</mo><mspace width="mediummathspace" /><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">w</mi><mi mathvariant="bold">x</mi></msub></mrow></math>"><span id="MathJax-Span-164" class="math"><span><span><span id="MathJax-Span-165" class="mrow"><span id="MathJax-Span-166" class="texatom"><span id="MathJax-Span-167" class="mrow"><span id="MathJax-Span-168" class="msubsup"><span><span><span id="MathJax-Span-169" class="mi">h</span></span><span><span id="MathJax-Span-170" class="mi">x</span></span></span></span></span></span><span id="MathJax-Span-171" class="mo">=</span><span id="MathJax-Span-172" class="mo">−</span><span id="MathJax-Span-173" class="mi">∇</span><span id="MathJax-Span-174" class="mo">×</span><span id="MathJax-Span-175" class="mspace"></span><span id="MathJax-Span-176" class="texatom"><span id="MathJax-Span-177" class="mrow"><span id="MathJax-Span-178" class="msubsup"><span><span><span id="MathJax-Span-179" class="mi">w</span></span><span><span id="MathJax-Span-180" class="mi">x.</span></span></span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">hx=−∇×wx</span></span>. But obviously, the <span id="MathJax-Element-16-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mi>c</mi><mi>u</mi><mi>r</mi><mi>l</mi></math>"><span id="MathJax-Span-181" class="math"><span><span><span id="MathJax-Span-182" class="mrow"><span id="MathJax-Span-183" class="mi">c</span><span id="MathJax-Span-184" class="mi">u</span><span id="MathJax-Span-185" class="mi">r</span><span id="MathJax-Span-186" class="mi">l</span></span></span></span></span><span class="MJX_Assistive_MathML">curl</span></span> of <span id="MathJax-Element-17-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mspace width="mediummathspace" /><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">w</mi><mi mathvariant="bold">x</mi></msub></mrow></math>"><span id="MathJax-Span-187" class="math"><span><span><span id="MathJax-Span-188" class="mrow"><span id="MathJax-Span-189" class="mspace"></span><span id="MathJax-Span-190" class="texatom"><span id="MathJax-Span-191" class="mrow"><span id="MathJax-Span-192" class="msubsup"><span><span><span id="MathJax-Span-193" class="mi">w</span></span><span><span id="MathJax-Span-194" class="mi">x</span></span></span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">wx</span></span> (<span id="MathJax-Element-18-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">h</mi><mi mathvariant="bold">x</mi></msub></mrow><mo>=</mo><mo>&#x2212;</mo><mi mathvariant="normal">&#x2207;</mi><mo>&#x00D7;</mo><mspace width="mediummathspace" /><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">w</mi><mi mathvariant="bold">x</mi></msub></mrow></math>"><span id="MathJax-Span-195" class="math"><span><span><span id="MathJax-Span-196" class="mrow"><span id="MathJax-Span-197" class="texatom"><span id="MathJax-Span-198" class="mrow"><span id="MathJax-Span-199" class="msubsup"><span><span><span id="MathJax-Span-200" class="mi">h</span></span><span><span id="MathJax-Span-201" class="mi">x</span></span></span></span></span></span><span id="MathJax-Span-202" class="mo">=</span><span id="MathJax-Span-203" class="mo">−</span><span id="MathJax-Span-204" class="mi">∇</span><span id="MathJax-Span-205" class="mo">×</span><span id="MathJax-Span-206" class="mspace"></span><span id="MathJax-Span-207" class="texatom"><span id="MathJax-Span-208" class="mrow"><span id="MathJax-Span-209" class="msubsup"><span><span><span id="MathJax-Span-210" class="mi">w</span></span><span><span id="MathJax-Span-211" class="mi">x</span></span></span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">hx=−∇×wx</span></span>), has components in <span id="MathJax-Element-19-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mi>j</mi><mspace width="mediummathspace" /><mi>a</mi><mi>n</mi><mi>d</mi><mspace width="mediummathspace" /><mi>k</mi></math>"><span id="MathJax-Span-212" class="math"><span><span><span id="MathJax-Span-213" class="mrow"><span id="MathJax-Span-214" class="mi">j</span><span id="MathJax-Span-215" class="mspace"></span><span id="MathJax-Span-216" class="mi">a</span><span id="MathJax-Span-217" class="mi">n</span><span id="MathJax-Span-218" class="mi">d</span><span id="MathJax-Span-219" class="mspace"></span><span id="MathJax-Span-220" class="mi">k</span></span></span></span></span><span class="MJX_Assistive_MathML">jandk</span></span> directions. The wave propagation is considered only in 1-D (<span id="MathJax-Element-20-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mi>i</mi></math>"><span id="MathJax-Span-221" class="math"><span><span><span id="MathJax-Span-222" class="mrow"><span id="MathJax-Span-223" class="mi">i</span></span></span></span></span><span class="MJX_Assistive_MathML">i</span></span>-direction). So, should I ignore the values in other directions (<span id="MathJax-Element-21-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mi>j</mi><mspace width="mediummathspace" /><mi>a</mi><mi>n</mi><mi>d</mi><mspace width="mediummathspace" /><mi>k</mi></math>"><span id="MathJax-Span-224" class="math"><span><span><span id="MathJax-Span-225" class="mrow"><span id="MathJax-Span-226" class="mi">j</span><span id="MathJax-Span-227" class="mspace"></span><span id="MathJax-Span-228" class="mi">a</span><span id="MathJax-Span-229" class="mi">n</span><span id="MathJax-Span-230" class="mi">d</span><span id="MathJax-Span-231" class="mspace"></span><span id="MathJax-Span-232" class="mi">k</span></span></span></span></span><span class="MJX_Assistive_MathML">jandk</span></span>)?. I am pretty sure that I am missing some mathematics in understanding the curl of a 1D vector field.</p>
<p>What will be the components of the potentials <span id="MathJax-Element-22-Frame" class="MathJax" data-mathml="//www.w3.org/1998/Math/MathML"><mi>b</mi><mspace width="mediummathspace" /><mi>a</mi><mi>n</mi><mi>d</mi><mspace width="mediummathspace" /><mrow class="MJX-TeXAtom-ORD"><msub><mi mathvariant="bold">h</mi><mi mathvariant="bold">x</mi></msub></mrow></math>"><span id="MathJax-Span-233" class="math"><span><span><span id="MathJax-Span-234" class="mrow"><span id="MathJax-Span-235" class="mi">b</span><span id="MathJax-Span-236" class="mspace"></span><span id="MathJax-Span-237" class="mi">a</span><span id="MathJax-Span-238" class="mi">n</span><span id="MathJax-Span-239" class="mi">d</span><span id="MathJax-Span-240" class="mspace"></span><span id="MathJax-Span-241" class="texatom"><span id="MathJax-Span-242" class="mrow"><span id="MathJax-Span-243" class="msubsup"><span><span><span id="MathJax-Span-244" class="mi">h</span></span><span><span id="MathJax-Span-245" class="mi">x</span></span></span></span></span></span></span></span></span></span><span class="MJX_Assistive_MathML">bandhx</span></span> looks like? Any references to this problem or curl operators of 1D vector is much appreciable.Please throw some light on my question. Many thanks and much appreciable for help. </p>
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</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div>Mon, 16 Oct 2017 15:02:50 +0000Sundaraelangovan selvam21709 at https://imechanica.orghttps://imechanica.org/node/21709#commentshttps://imechanica.org/crss/node/21709FEA simulation of double joints in shear loading
https://imechanica.org/node/21557
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Hi all,</p>
<p> </p>
<p>I have a question about an FEA simulation. Particularly, about the boumndary conditions that need to be applied to run this simulation. </p>
<p> </p>
<p>attempt1:</p>
<p> </p>
<p>I fixed the right end of the plates and applied loading to the left end. This resulted in stresses go through only the top joint region (W1 in figure attached). </p>
<p> </p>
<p>From our understanding, the deformation is got to be symmetric on both the plates. But, when we applied these BCs, it is not smmetric. </p>
<p> </p>
<p> </p>
<p>attempt-2:</p>
<p> </p>
<p>I applied forces on both the ends as shown on top of the attached image. I contrained 2 nodes on exact middle portions of the plates in X direction. Constrained right most and left most edges where force is applied in Y direction. </p>
<p> </p>
<p>The deformation looks pratical, but this is not the best case as we are not letting the plate portion that is constrained in Y direction to deform as result of poisson's ratio.</p>
<p> </p>
<p>Any thoughts on this simulation will be beneficial. </p>
<p> </p>
<p> </p>
<p>Also, </p>
<p> </p>
<p>are there any symmetry anti-symmetry conditions that I haven't looked into? Please let me know.</p>
<p> </p>
<p>Yuan Krishna</p>
<p> </p>
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</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/128">education</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/935">FEA</a></div><div class="field-item odd"><a href="/taxonomy/term/9254">Bonded Joints</a></div><div class="field-item even"><a href="/taxonomy/term/7023">Bolted joints</a></div></div></div>Mon, 04 Sep 2017 00:24:24 +0000krishna_yuan21557 at https://imechanica.orghttps://imechanica.org/node/21557#commentshttps://imechanica.org/crss/node/21557PhD candidate for finite element developer
https://imechanica.org/node/21516
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</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/73">job</a></div></div></div>Wed, 16 Aug 2017 23:16:22 +0000mandaldi21516 at https://imechanica.orghttps://imechanica.org/node/21516#commentshttps://imechanica.org/crss/node/21516Finite Element Software Developer
https://imechanica.org/node/21436
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Altair Engineering Inc is seeking a Software Engineer to assist in the development of OptiStruct, a commercial finite element code mainly involved in the structural dynamics and acoustics domain. The candidate will be mainly responsible for writing software in Fortran and C++. It is also desirable for candidates to be familiar with the noise/vibration/harshness (NVH) arena. Click here to learn about Altair’s OptiStruct: <a href="http://www.altairhyperworks.com/product/OptiStruct">http://www.altairhyperworks.com/product/OptiStruct</a>.</p>
<p><strong>Responsibilities:</strong></p>
<ul><li>To derive mathematical formulation mainly in finite element method.</li>
<li>Must be able to program with Fortran and C++</li>
<li>Handle large code and design code day to day basis.</li>
<li>Software testing and debugging.</li>
<li>Strong organizational skills and ability to multi-task.</li>
<li>Ability to work in small teams with little or no supervision is a must</li>
</ul><p><strong>Requirements:</strong></p>
<ul><li>Master’s or PhD in Mechanical, Civil or Aerospace Engineering.</li>
<li>Strong knowledge in Finite Element Analysis (FEA) and Structural Dynamics.</li>
<li>Programming knowledge with Fortran and C++.</li>
<li>Sound mathematical knowledge.</li>
<li>Familiarity with Linux.</li>
<li>Knowledge of HyperMesh and Optistruct products preferred.</li>
<li>Must be a team player.</li>
</ul></div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/73">job</a></div></div></div>Fri, 21 Jul 2017 19:41:53 +0000mandaldi21436 at https://imechanica.orghttps://imechanica.org/node/21436#commentshttps://imechanica.org/crss/node/21436Model two heat source for arc welding simulation using ls-dyna??
https://imechanica.org/node/21426
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Hallo,</p>
<p> </p>
<p id="yui_3_14_1_1_1500558973219_1564">i am trying to compute the temperature distribution in arc welding simulation by using two heat source simultaneously (first one on the top of the plate and second one on the bottom of the plate). For this simulation i am using the software LS-DYNA. But, unfortunately my simulation terminate with following error which i am unable to understand:</p>
<p> </p>
<p id="yui_3_14_1_1_1500558973219_1568">*** Error 60110 (IMP+110)<br /> terminating : MF2 Factorization error 14<br /> E r r o r t e r m i n a t i o n</p>
<p> </p>
<p>When i compute the temperature field by using only one heat source then it works perfectly.</p>
<p> </p>
<p>can anyone give me some suggestion regadring this error message.</p>
<p> </p>
<p>Regards</p>
<p> </p>
<p id="yui_3_14_1_1_1500558973219_1571">Braj</p>
<p><em>Model two heat source for arc welding simulation using ls-dyna??</em>. Available from: <a href="https://www.researchgate.net/post/Model_two_heat_source_for_arc_welding_simulation_using_ls-dyna">https://www.researchgate.net/post/Model_two_heat_source_for_arc_welding_simulation_using_ls-dyna</a> [accessed Jul 20, 2017].</p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div>Thu, 20 Jul 2017 13:56:45 +0000ntuecd21426 at https://imechanica.orghttps://imechanica.org/node/21426#commentshttps://imechanica.org/crss/node/21426Temperature field simulation by using LS-DYNA??
https://imechanica.org/node/21425
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Hallo welding simulation experts,</p>
<p> </p>
<p>i am trying to simulate the temperature field in a single pass weld by using the commercial software LS-DYNA. I had simulated the welding torch by using beam element concept and it works perfect.</p>
<p> </p>
<p id="yui_3_14_1_1_1500558827424_1502">The welding torch (beam element) moves with a constant velocity from one node of the plate to the end node of the plate on a straight trajectory. I want to simulate the cooling phenomena , i.e. when the welding torch reaches the end node of the plate then it should stop providing more heat, so one can see how the temperature field is distributed once the welding torch is off.</p>
<p> </p>
<p>Can anyone help me out, how can i do such kind of simulation by using LS-DYNA.</p>
<p> </p>
<p>Thanking you</p>
<p> </p>
<p id="yui_3_14_1_1_1500558827424_1505">Braj</p>
<p><em>Temperature field simulation by using LS-DYNA??</em>. Available from: <a href="https://www.researchgate.net/post/Temperature_field_simulation_by_using_LS-DYNA">https://www.researchgate.net/post/Temperature_field_simulation_by_using_LS-DYNA</a> [accessed Jul 20, 2017].</p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div>Thu, 20 Jul 2017 13:55:51 +0000ntuecd21425 at https://imechanica.orghttps://imechanica.org/node/21425#commentshttps://imechanica.org/crss/node/21425Question reg ABAQUS-VUMAT and Updated Lagrangian formulation.
https://imechanica.org/node/21424
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Hello all,</p>
<p>I am working on implementing a viscoelastic constitutive model from a hyperelastic stored energy potential (for finite-elasticity) and a dissipation potential (for the viscouls evolution). The elastic constitutive relation, hence derived from the stored energy potential is rate-independent and it is expressed as T(Cauchy's Stress) = f(B), where B is the Left-cauchy green deformation tensor.</p>
<p>The evolution equation is derived out in an objective rate form, which I am integrating over time using a 2nd order accurate explicit method.</p>
<p>My question:</p>
<p>1. How does I let ABAQUS know/(How do I toggle) to use Updated Lagrangian formulation, given that I code my constitutive relation in the format mentioned above?</p>
<p> </p>
<p>Thank you.</p>
<p>Srikanth</p>
<p>Research Scholar</p>
<p>Department of Mechanical Engineering</p>
<p>IIT Madras, India.</p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/795">viscoelasticity</a></div><div class="field-item odd"><a href="/taxonomy/term/11555">Abaqus VUMAT</a></div><div class="field-item even"><a href="/taxonomy/term/1588">VUMAT</a></div><div class="field-item odd"><a href="/taxonomy/term/289">ABAQUS</a></div></div></div>Wed, 19 Jul 2017 14:37:25 +0000ksrikanth52321424 at https://imechanica.orghttps://imechanica.org/node/21424#commentshttps://imechanica.org/crss/node/21424LS DYNA-Structural Mechanics
https://imechanica.org/node/21368
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>I am trying to simulate a seismic earthquake analysis in order to study collapse pattern on LS DYNA.</p>
<p>I have build the keyword from scratch.Although, I am new to LS Dyna, I have never performed such a simulation, I have build a test model consisting of 2 columns joined by a beam resting on a finite element representing soil.</p>
<p>The soil block(Red) consists of a block 15mx45mx12m consisting of two 9mx9mx6m cavities for non linear soil(Blue). The columns(Green) are 3mx3mx9m with beam(Yellow) being 3mx27mx3m.(This sounds far unrealistic model, so please don't mind as this is just a test simulation as I am only trying to figure out how it is performed.For reference, please see the image"<strong>test model Image for reference</strong>")</p>
<p>The material used for the columns and a beam is concrete model RHT(272). The material used for soil is soil_concrete(078).</p>
<p>The contacts used are Tied surface to surface between all the contact regions in the model.</p>
<p>I have applied gravity load for first 25 seconds for pre-stressing using dynamic relaxation(convergence is observed at 5-6 seconds) before introducing earthquake acceleration loads(in directions x, y & z) at time 20 seconds in the analysis.</p>
<p>The moment I run the session, I get a GMBIN error.(Please see the image"<strong>GMBIN error</strong>")</p>
<p>Also when I replace the soil(Red) by material PML_Elastic(230), I get an error that elements are missing from PML block.(Please see the image"<strong>PML error</strong>")</p>
<p>Please someone tell me what is wrong and how to fix this.</p>
<p>My whole intention behind this is to simulate a progressive collapse of a structure made of several bricks.</p>
<p>Thanks in advance.</p>
<p> </p>
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<tr class="odd"><td><span class="file"><img class="file-icon" alt="Image icon" title="image/jpeg" src="/modules/file/icons/image-x-generic.png" /> <a href="https://imechanica.org/files/error%20gmbin.JPG" type="image/jpeg; length=45898" title="error gmbin.JPG">GMBIN error</a></span></td><td>44.82 KB</td> </tr>
<tr class="even"><td><span class="file"><img class="file-icon" alt="Image icon" title="image/jpeg" src="/modules/file/icons/image-x-generic.png" /> <a href="https://imechanica.org/files/SSI.JPG" type="image/jpeg; length=148691" title="SSI.JPG">test model Image for reference</a></span></td><td>145.21 KB</td> </tr>
<tr class="odd"><td><span class="file"><img class="file-icon" alt="Image icon" title="image/jpeg" src="/modules/file/icons/image-x-generic.png" /> <a href="https://imechanica.org/files/error%20ls%20dyna%20pml.JPG" type="image/jpeg; length=88695" title="error ls dyna pml.JPG">PML error</a></span></td><td>86.62 KB</td> </tr>
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</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div>Sat, 01 Jul 2017 14:57:04 +0000Jai Khullar21368 at https://imechanica.orghttps://imechanica.org/node/21368#commentshttps://imechanica.org/crss/node/21368why natural frequency of functionally graded plate decreases while increasing temperature of FGM plate
https://imechanica.org/node/21058
<div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Free Tags: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/11419">Modal analyssis of FGM plates in thermal environment</a></div></div></div>Thu, 23 Mar 2017 21:01:42 +0000bohrapankaj21058 at https://imechanica.orghttps://imechanica.org/node/21058#commentshttps://imechanica.org/crss/node/21058constitutive model of polymers
https://imechanica.org/node/20913
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>I have been studying constitutive models of polymers for four years, and I have written vumat codes of several constitutive models, such as BPA, Arruda-Boyce, Mulliken-Boyce, Johnson-Cook, DSGZ and G’Sell-Jonas, but I don't understand the theory of anand constitutive model. If anybody share the corresponding the vumat codes of <span>anand constitutive model, I will appreciate his or her help very much, and I am also willing to help him or her by sharing my codes with </span><span> </span><span>him or her. My mailbox is <a href="mailto:wanghaitao@hust.edu.cn">wanghaitao@hust.edu.cn</a>. Looking forward to your letter.</span><span> </span></p>
<p>By the way, the corresponding papers of anand are as follows:</p>
<p>(1) A theory of amorphous solids undergoing large deformations, with application to polymeric glasses</p>
<p>(2) On modeling the micro-indentation response of an amorphous polymer</p>
<p>(3) A thermo-mechanically coupled theory for large deformations of amorphous polymers. Part I: Formulation</p>
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<tr class="odd"><td><span class="file"><img class="file-icon" alt="PDF icon" title="application/pdf" src="/modules/file/icons/application-pdf.png" /> <a href="https://imechanica.org/files/A%20theory%20of%20amorphous%20solids%20undergoing%20large%20deformations.pdf" type="application/pdf; length=309737">A theory of amorphous solids undergoing large deformations.pdf</a></span></td><td>302.48 KB</td> </tr>
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</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div><div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div>Thu, 16 Feb 2017 08:48:34 +0000yiqinuli20913 at https://imechanica.orghttps://imechanica.org/node/20913#commentshttps://imechanica.org/crss/node/20913XFEM in Abaqus Explicit
https://imechanica.org/node/20813
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Hello Everybody,</p>
<p>one interesting question:</p>
<p>As I found, there is no possibility to use XFEM in Abaqus Explicit. !!!</p>
<p>maybe, somebody has any idea or trick to use XFEM in Abaqus Explicit?!!!</p>
<p>thanks in advance,</p>
</div></div></div><div class="field field-name-taxonomy-forums field-type-taxonomy-term-reference field-label-above"><div class="field-label">Forums: </div><div class="field-items"><div class="field-item even"><a href="/forum/357">Computational Mechanics Forum</a></div></div></div>Fri, 20 Jan 2017 15:19:21 +0000Hassan Nazari20813 at https://imechanica.orghttps://imechanica.org/node/20813#commentshttps://imechanica.org/crss/node/20813Error | iMechanica