Wenbin Yu's blog
http://imechanica.org/blog/3392
enPurdue Composites Manufacturing & Simulation Center is Hiring
http://imechanica.org/node/21162
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Purdue Composites Manufacturing & Simulation Center is looking for outstanding candidates to fill multiple faculty positions at the level of Full, Associate and Assitant Professor in composites manufacturing & simulation. Please check <span><a href="https://cdmhub.org/explore/newsletter">https://cdmhub.org/explore/newsletter</a> for mroe details. </span></p>
</div></div></div>Wed, 19 Apr 2017 16:48:57 +0000Wenbin Yu21162 at http://imechanica.orghttp://imechanica.org/node/21162#commentshttp://imechanica.org/crss/node/21162Turn your computer codes into Apps connected to HPC in the Cloud
http://imechanica.org/node/21148
<div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/5863">cloud computing</a></div><div class="field-item odd"><a href="/taxonomy/term/10410">cdmHUB.org</a></div></div></div><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 Imechanicians, I hope this turns out to be useful for some of you who are interested in sharing their computer codes. We are working on a free platform, cdmHUB.org, to allow users to quickly turn your scripts into Apps connected with HPC power in the cloud. Currently, the system can easily handle Linux or Windows executables. We are developing new functionalities so that other typical <span>scripts such as Abaqus UMATs, Python scripts, matlab scripts can also be disseminated as launchable Apps in cloud. No change of your codes is necessary. </span><span>These Apps can be executed on any device connected to Internet through a broswer. Of course, you have complete control of your code and you decide who can use your code. cdmHUB also provides many functionalities such as secure groups, projects, discussion boards, blogs and wikis for real-time collaborations in a virtual environment. Supported by DARPA and industrial sponsors, we are providing cdmHUB as a free platform for all users. Our technical focus is on design and manufacturing of composites (materials featuring anisotropy and heterogeneity at length scale larger than micron). I think much of your work are relevant to this platform. To get a test of its capabilities, you can try to use your favorite device to carry out a multiscale constitutive modeling of textile composites at </span><a href="https://cdmhub.org/resources/texgen4sc">https://cdmhub.org/resources/texgen4sc.</a> To understand more about this platform, please see <a href="https://cdmhub.org/resources/1246">https://cdmhub.org/resources/1246</a>. </p>
<p> </p>
</div></div></div>Thu, 13 Apr 2017 18:33:18 +0000Wenbin Yu21148 at http://imechanica.orghttp://imechanica.org/node/21148#commentshttp://imechanica.org/crss/node/21148Webinar: Structure Genome: A Revolutionary Multiscale Approach to Bridging Materials Genome and Structural Analysis
http://imechanica.org/node/20932
<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>Register the free webinar at </span><span><span><a href="https://www.nafems.org/events/nafems/2017/multiscalefeb2017/">https://www.nafems.org/events/nafems/2017/multiscalefeb2017/</a>. </span></span></p>
<p><span>Materials Genome Initiative (MGI) aims to deliver the required infrastructure and training to accelerate discovery, developing, manufacturing, and deploying of advanced materials in a more expeditious and economical way. However, material by definition is a matter from which a thing can be made of. Ultimately speaking, it is not the material performance, but the structural performance or rather system performance we are after. Thus, materials genome must integrate with structural analysis to maximize the benefits of accelerated development of advanced structural materials.</span></p>
<p> To fill the gap between materials genome and composite structural analysis, a new concept, Structure Genome (SG) is proposed. SG acts as the basic building block connecting materials and structures and contains all the constitutive information needed for a structure the same fashion as the genome contains all the intrinsic information for an organism's growth and development. The Mechanics of Structure Genome (MSG) represents a revolutionary approach to multiscale modeling drastically different from the conventional bottom-up multiscale modeling approaches. The principle of minimum information loss (PMIL) is used to avoid a priori assumptions commonly invoked in other approaches and decouples the original problem into two sets of analyses: a constitutive modeling and a structural analysis. The structural analysis can be routinely performed in commercial FEA software. MSG confines all approximations to the constitutive modeling which can construct constitutive models for all types of structures including 3D solids, 2D plates/shells, and 1D beams, directly linking the structural properties with microstructural details. When specialized to 3D structures, this approach provides a general-purpose micromechanics theory which can provide a better alternative to the RVE analysis and asymptotic homogenization theory in terms of efficiency, accuracy, and versatility. MSG provides a unified treatment for all microstructures (periodic, aperiodic, partially periodic). With MSG, multiscale constitutive modelling is simplified to answer three fundamental questions: 1) what is the original model needed for capturing relevant physics? 2) what is the model wanted for a particular design? 3) what is the SG? With answers of these three questions, MSG allows one to choose the starting scale and ending scale and capture details as needed and affordable. </p>
</div></div></div>Sun, 19 Feb 2017 19:38:31 +0000Wenbin Yu20932 at http://imechanica.orghttp://imechanica.org/node/20932#commentshttp://imechanica.org/crss/node/20932ASC 2017 Abstract due Feb. 17
http://imechanica.org/node/20898
<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 Fellow mechanicians, if your work is related with composites, you might want to consider presending your work on the American Society for Composites Annual Conference to be held on <strong>Purdue campus.</strong> The abstract is due <strong>this Friday (Feb. 17). </strong>Please go to <a href="https://urldefense.proofpoint.com/v2/url?u=https-3A__cdmhub.org_groups_asc2017&d=DQMFAg&c=ilBQI1lupc9Y65XwNblLtw&r=TxmXli54aoFmGBMYl67ZPuO0rxla541wVJ5UoH9athE&m=T3HKXbcVMcFtM7_vp7PPGOhg2Cac-3MS7zuGU6Ib6Ic&s=82nUPpsreEcwa96NDN3uEzEjwxSEhvlD3qz4rij_xxE&e=">https://cdmhub.org/groups/asc2017</a>, click Submit. Students, please take advantage of the excellent opportunity to apply for the 20 travel scholarships ($800 value each). Details can be found at <a href="https://urldefense.proofpoint.com/v2/url?u=https-3A__cdmhub.org_groups_asc2017_scholarship&d=DQMFAg&c=ilBQI1lupc9Y65XwNblLtw&r=TxmXli54aoFmGBMYl67ZPuO0rxla541wVJ5UoH9athE&m=T3HKXbcVMcFtM7_vp7PPGOhg2Cac-3MS7zuGU6Ib6Ic&s=b7DD6vQgFztBcYTBoZhuxk-dh6EQMJzqDi4UGuYMI-w&e=">https://cdmhub.org/groups/asc2017/scholarship</a>. Professors, please encourage potential students to apply. </p>
<p>Thanks a lot for your attention!</p>
<p><span>Wenbin</span></p>
<p> </p>
</div></div></div>Mon, 13 Feb 2017 22:23:05 +0000Wenbin Yu20898 at http://imechanica.orghttp://imechanica.org/node/20898#commentshttp://imechanica.org/crss/node/20898Travel Scholarship and Code Competition for ASC 2017
http://imechanica.org/node/20844
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>To motivate students to attend the conference, ASC 2017 offers up to 20 travel scholarships including free registration and travel expenses up to $500. The top six will also receive additional cash prizes. Details can be found at <a href="https://cdmhub.org/groups/asc2017/scholarship" target="_blank">https://cdmhub.org/groups/asc2017/scholarship</a>. Professors, please encourage your students to apply. The abstract due date is Feb. 17. More details about the conference can be found at <a href="https://cdmhub.org/groups/asc2017">https://cdmhub.org/groups/asc2017</a>.</p>
<p><span>Wenbin</span></p>
</div></div></div>Wed, 01 Feb 2017 15:36:27 +0000Wenbin Yu20844 at http://imechanica.orghttp://imechanica.org/node/20844#commentshttp://imechanica.org/crss/node/20844American Society for Composites Annual Conference Open for Submission
http://imechanica.org/node/20833
<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>We are delighted to invite you to attend the American Society for Composites Annual Technical Conference which will be held on the campus of Purdue University, Oct. 23-25, 2017. The conference website is: </span><a class="js-link post-link" href="https://www.linkedin.com/redir/redirect?url=https%3A%2F%2Fcdmhub%2Eorg%2Fgroups%2Fasc2017&urlhash=1MV5&_t=tracking_anet" target="_blank">https://cdmhub.org/groups/asc2017</a><span>. </span></p>
<p><span>The conference welcomes all papers related with various aspects of composites science and technology. There are total of 25 tracks organized. The important dates are:</span><br /><span>Abstract due: Feb. 17, 2017.</span><br /><span>Full paper due: June 16, 2017.</span><br /><span>Registration starts: July 1, 2017. </span><span><br /></span></p>
</div></div></div>Sun, 29 Jan 2017 20:29:04 +0000Wenbin Yu20833 at http://imechanica.orghttp://imechanica.org/node/20833#commentshttp://imechanica.org/crss/node/20833International Conference on Composites Materials (ICCM-21), Xi'an, China, August 20-25, 2017
http://imechanica.org/node/20756
<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>The 21st International Conference on Composites Materials (ICCM-21) will be held in Xi'an, China, August 20-25, 2017. ICCM, the most premier conference in the field of composite materials, aims at encouraging the exchange of the researches and insights from scientists and scholars, and promoting research, development and use of composite material and structures. You are welcome to submit to Track 2.2 Multiscale Modeling of Structures to share your great ideas on multiscale modeling. Please see </span><span><span><a href="http://www.iccm21.org/">http://www.iccm21.org/</a> for more details. Remember to select Track 2.2. Thanks a lot! </span></span></p>
<p><span> </span></p>
</div></div></div>Sat, 07 Jan 2017 20:50:28 +0000Wenbin Yu20756 at http://imechanica.orghttp://imechanica.org/node/20756#commentshttp://imechanica.org/crss/node/20756Textile Composite Property Calculator in the Cloud
http://imechanica.org/node/20639
<div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/8069">textile composites</a></div><div class="field-item odd"><a href="/taxonomy/term/18">micromechanics</a></div></div></div><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 hope this information will be helpful for some researchers. We recently integrated TexGen with SwiftComp, called <a href="https://cdmhub.org/resources/texgen4sc">TexGen4SC</a>, to provide a very easy app to compute thermoelastic properties for textile composites for all the types of woven microstructures which can be generated by TexGen. This tool can achieve RVE analysis accuracy with a very small fraction of its computing time. This tool can respect the finite thickness of a woven fabric. It can be freely launched on any device (smart phones, ipads, etc) connected to Internet. I thought this might be useful for some of Imechanica members. Feel free to make use of it. To get a quick start, please watch our tutorial video at <a href="https://www.youtube.com/watch?v=VSjZ-boG4Bg&list=PLGwp8OYDfmxFhtnDNJVRUJ8J-HP8FsnIU">Multiscale Structural Mechanics</a>. </p>
</div></div></div>Fri, 02 Dec 2016 03:03:29 +0000Wenbin Yu20639 at http://imechanica.orghttp://imechanica.org/node/20639#commentshttp://imechanica.org/crss/node/20639A Better Alternative to RVE Analysis
http://imechanica.org/node/20517
<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-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/11200">Mechanics of Structure Genome</a></div><div class="field-item odd"><a href="/taxonomy/term/18">micromechanics</a></div><div class="field-item even"><a href="/taxonomy/term/11391">composites.</a></div></div></div><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>RVE analysis is popular for computational homogenization. It can be used independently for virtual testing or as a module for multiscale modeling. Its popularity is mainly due to the maturity and acceptance of commercial finite element software. RVE analysis usually requires a 3D domain to obtain 3D properties and local fields. If a 2D RVE is used, only 2D properties and local fields are obtained. To obtain the complete set of properties, multiple analysis is needed. For example, to obtain the complete stiffness matrix, six 3D RVE analyses are needed. The main drawbacks are the computational cost, and difficulty in applying the right boundary conditions. </span></p>
<p>The recently discovered mechanics of structure genome (MSG) and its companion code SwiftComp, when specialized to 3D structures, can provide a general-purpose micromechanics theory. Many examples, including the <a href="https://cdmhub.org/projects/mmsimulationchalleng">micromechanics simulation challenge</a> have been used to demonstrate that MSG/SwiftComp is more versatile, efficient, and simpler than RVE analysis with out lossing any accuracy and geometric modeling flexibility. More detailed comparison between MSG and RVE analysis can be found <a href="https://cdmhub.org/blog/2016/10/rve-analysis-vs-mechanics-of-structure-genome">here</a>. <span>SwiftComp can be freely launched in the cloud at </span><a href="https://cdmhub.org/resources/scstandard">https://cdmhub.org/resources/scstandard</a><span>. In other words, one can run a super-efficient "RVE analysis" on any devices including smart phones and tablets connected to Internet via a browser. Various GUIs are available for users to choose from including Gmsh, TexGen, ANSYS, and ABAQUS4, all of which are free available on </span><a href="http://cdmhub.org/">cdmHUB</a><span>. </span><span> </span></p>
</div></div></div>Thu, 27 Oct 2016 02:37:07 +0000Wenbin Yu20517 at http://imechanica.orghttp://imechanica.org/node/20517#commentshttp://imechanica.org/crss/node/205172017 ASC Annual Technical Conference at Purdue
http://imechanica.org/node/20460
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Purdue will host the 32nd American Society for Composites (ASC) Annual Technical Conference. This conference convene composites researchers from around the world to interact with industry, government and academia, fostering collaborations among all stake holders in the composites community. More detailed information can be found at the conference website at <a href="https://cdmhub.org/groups/asc2017">https://cdmhub.org/groups/asc2017</a>.</p>
</div></div></div>Fri, 14 Oct 2016 18:14:37 +0000Wenbin Yu20460 at http://imechanica.orghttp://imechanica.org/node/20460#commentshttp://imechanica.org/crss/node/204602016 cdmHUB Annual Workshop at Purdue
http://imechanica.org/node/20418
<div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/949">Workshop</a></div><div class="field-item odd"><a href="/taxonomy/term/1910">multiscale modeling</a></div></div></div><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>Join us for the 2016 Composites Simulation Workshop at Purdue University. </span><span>Learn about and engage with world-class researchers and industry experts in </span><span>multi-scale composites modeling. Interact with state-of-the-art composites </span><span>simulation software; hear expert, cutting-edge advances in strength and </span><span>lifecycle prediction modeling. Experience composites 3D printing and advances </span><span>in composites manufacturing modeling for high-rate automotive applications.</span></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>
<tbody>
<tr class="odd"><td><span class="file"><img class="file-icon" alt="" title="application/pdf" src="/modules/file/icons/application-pdf.png" /> <a href="http://imechanica.org/files/cdmHUB-annual-workshop-flyer-2016.pdf" type="application/pdf; length=213622">cdmHUB-annual-workshop-flyer-2016.pdf</a></span></td><td>208.62 KB</td> </tr>
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</div></div></div>Fri, 07 Oct 2016 20:18:41 +0000Wenbin Yu20418 at http://imechanica.orghttp://imechanica.org/node/20418#commentshttp://imechanica.org/crss/node/20418cdmHUb Hands-on Workshop for Composites Learning, Teaching and Research in the Cloud
http://imechanica.org/node/20250
<div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/10410">cdmHUB.org</a></div></div></div><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>Join us at the American Society for Composites 31st Technical Conference (Williamsburg, VA) for a hands-on workshop, on September 18, from 7:00–9:00pm, on how to use </span><a class="js-link post-link" href="http://www.linkedin.com/redir/redirect?url=cdmHUB%2Eorg&urlhash=Adrn&_t=tracking_anet" target="_blank">cdmHUB.org</a><span> for composites learning, teaching, and research in the cloud. This workshop features an overview of the cdmHUB cyberinfrastructure, and how to use cdmHUB for learning, teaching, and research. We will demonstrate how to use cdmHUB to develop and launch composites simulation tools. Please bring your laptop or tablet so that you can enjoy real-time of exercise all the collaborative</span><br /><span>functionalities of cdmHUB and immediate access of a vast array of composites resources. </span><br /><span>Details can be found in the attached flyer. Please explore </span><a class="js-link post-link" href="http://www.linkedin.com/redir/redirect?url=cdmHUB%2Eorg&urlhash=Adrn&_t=tracking_anet" target="_blank">cdmHUB.org</a> to know more.</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>
<tbody>
<tr class="odd"><td><span class="file"><img class="file-icon" alt="" title="application/pdf" src="/modules/file/icons/application-pdf.png" /> <a href="http://imechanica.org/files/cdmHUB-ASC-Workshop.pdf" type="application/pdf; length=221744">cdmHUB-ASC-Workshop.pdf</a></span></td><td>216.55 KB</td> </tr>
</tbody>
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</div></div></div>Fri, 02 Sep 2016 01:45:29 +0000Wenbin Yu20250 at http://imechanica.orghttp://imechanica.org/node/20250#commentshttp://imechanica.org/crss/node/20250RVE analysis without BCs and periodic mesh requirements
http://imechanica.org/node/20013
<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-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/18">micromechanics</a></div><div class="field-item odd"><a href="/taxonomy/term/934">Composites</a></div><div class="field-item even"><a href="/taxonomy/term/1092">constitutive modeling</a></div><div class="field-item odd"><a href="/taxonomy/term/11200">Mechanics of Structure Genome</a></div><div class="field-item even"><a href="/taxonomy/term/11201">SwiftComp</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>RVE analysis becomes a routine exercise in material modeling. Usually it is carried out using finite element codes such as ABAQUS or ANSYS. The main thing one should pay attention is to applying the right boundary conditions. It is settled that periodic boundary conditions are the preferred boundary conditions to be applied. The BCs are that u_i-\epsilon_{ij}x_j should be equal on the corresponding edges. This type of boundary conditions can be applied using coupled equations constraints. This requires that one creates a mesh with corresponding nodes on periodic edges. For real, complex microstructures, this could be a challenge. Another issue that with a 2D RVE analysis, one can only obtain in-plane properties and local fields, for 3D properties and local fields, 3D RVE analysis are always needed. Six 3D analyses are needed to compute the complete set of 3D elastic properties. Another analysis is needed to compute the local fields for each global state. </p>
<p>A recently developed general-purpose multiscale constitutive modeling code called SwiftComp based on <a href="http://imechanica.org/node/18928">Mechanics of Structure Genome</a>, can be used for micromechanics which is essentially a RVE analysis for dummies. The user does not have to specify the boundary conditions and periodic mesh is not required. All the user has to do is to provide the finite element mesh as input. Another unique feature of SwiftComp is that it can compute complete set of 3D properties from a 2D RVE if the material features 2D periodicity such as unidirectional fiber reinforced composites. All the properties are computed within one analysis and thus it is at least six times more efficient than traditional 3D RVE analysis. The code can be launched freely in the cloud at <a class="js-link post-link" href="http://www.linkedin.com/redir/redirect?url=https%3A%2F%2Fcdmhub%2Eorg%2Fresources%2Fscstandard&urlhash=O970&_t=tracking_anet" target="_blank">https://cdmhub.org/resources/scstandard</a> or used as a plugin for ABAQUS or ANSYS. You are welcome to try it to see the difference from the RVE analysis you are familiar with. </p>
<p> </p>
</div></div></div>Sun, 19 Jun 2016 21:56:48 +0000Wenbin Yu20013 at http://imechanica.orghttp://imechanica.org/node/20013#commentshttp://imechanica.org/crss/node/20013AIAA ICME Prize
http://imechanica.org/node/19921
<div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/9525">ICME</a></div><div class="field-item odd"><a href="/taxonomy/term/2434">Award</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p class="MsoNormal">Dear Imechanicians,</p>
<p class="MsoNormal">Under the auspices of the Materials Genome Initiative (MGI) and to “enable the optimization of the materials, manufacturing processes, and component design long before components are fabricated, by integrating the computational processes involved into a holistic system”, the AIAA Materials Technical Committee has established an ICME (Integrated Computational Materials Engineering) Prize for the best aerospace focused ICME project. The purpose of the ICME Prize is to stimulate computational design in a team environment and to instill product performance and certification requirement early in the design process. The inaugural ICME prize competition is to take place at the AIAA SciTech 2018 conference in January 2018. </p>
<p> </p>
<p class="MsoPlainText">On behalf of the ICME Prize Committee I’m soliciting your assistance in informing individuals interested in participating in this unique competition. In addition to a $1500 award, the ICME Prize winners may have an internship opportunities with prize sponsors Purdue University <a href="https://cdmhub.org/">cdmHUB</a>, NASA, and Rolls-Royce. Further details of the prize can be found at <a href="http://www.aiaa.org/icme/">http://www.aiaa.org/icme/</a>.</p>
<p class="MsoPlainText"> </p>
<p class="MsoPlainText">Wenbin</p>
<p class="MsoPlainText"> </p>
</div></div></div>Wed, 01 Jun 2016 16:32:42 +0000Wenbin Yu19921 at http://imechanica.orghttp://imechanica.org/node/19921#commentshttp://imechanica.org/crss/node/19921Micromechanics Simulation Challenge
http://imechanica.org/node/19379
<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-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/18">micromechanics</a></div><div class="field-item odd"><a href="/taxonomy/term/350">simulation</a></div><div class="field-item even"><a href="/taxonomy/term/3823">challenge</a></div></div></div><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><a href="https://cdmhub.org/">cdmHUB</a> has completed the level I micromechanics simulation challenge. Several micromechanics methods/tools including both commercially available tools such as </span><span>Altair MDS, ESI VPS, Digimat, SwiftComp and research codes such as MAC/GMC/HFGMC and FVDAM, </span><span>are used to analyze six typical 2D/3D microstructures. All the results and model files, inputs and outputs, and the report are hosted on cdmHUB as a live project at </span><a href="https://cdmhub.org/projects/mmsimulationchalleng/">https://cdmhub.org/projects/mmsimulationchalleng/</a><span>. Some tools can also be directly launched from cdmHUB. If you have a micromechanics code/tool, you are welcome to contribute your own results. These problems are also a good learning tool for students who want to study micromechanics. </span></p>
<p><span>Level I problems focus on linear thermoelastic properties and corresponding local fields. We are starting to draft level II problems which will focus on nonlinear problems. If you want to contribute, please feel free to let me know.</span></p>
<p> </p>
</div></div></div>Mon, 25 Jan 2016 23:00:52 +0000Wenbin Yu19379 at http://imechanica.orghttp://imechanica.org/node/19379#commentshttp://imechanica.org/crss/node/19379ICME Prize
http://imechanica.org/node/19259
<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-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><span>The AIAA Materials Technical Committee (TC) with the support of Composite Design and Manufacturing HUB (<a href="https://cdmhub.org/">cdmHUB</a>), NASA (National Aeronautics and Space Administration) and Rolls-Royce Corporation funding have established an ICME prize for the </span><a title="best aerospace-focused ICME project" href="http://www.aiaa.org/uploadedFiles/Membership_and_Communities/Recognition/ICMEBackground.pdf" target="_blank">best aerospace-focused ICME project</a><span>. More details can be found at </span><span><span><a href="http://www.aiaa.org/ICME/">http://www.aiaa.org/ICME/</a>.</span></span></p>
</div></div></div>Fri, 18 Dec 2015 01:35:54 +0000Wenbin Yu19259 at http://imechanica.orghttp://imechanica.org/node/19259#commentshttp://imechanica.org/crss/node/19259Journal Club Theme of October 2015: Mechanics of Structure Genome
http://imechanica.org/node/18928
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p class="MsoNormal"><span>The aim of this post is to introduce the mechanics of structure genome (MSG) as a possible unified approach for constitutive modeling of structures and materials. Because this discussion relates with structural mechanics and micromechanics, two familiar topics which have been studied by many, it is difficult to cite all the relevant references in a blog post without missing important ones. Thus, I only share some general understanding of relevant topics which are available from typical textbooks. Nevertheless, I am eager to provide any reference needed to clarify any points which you think need more details. </span></p>
<p><span><strong><span>Structures vs Materials</span></strong></span><br /></p><p class="MsoNormal"><span>Structures and materials often appear together and sometimes are used interchangeably. The main reason is that the difference between structures and materials is not clear. Our first solid mechanics course, usually called either strength of materials or mechanics of materials, mainly covers structural topics: rods, shafts, columns, beams, pressure vessels, etc. With the increasing capabilities of engineering microstructure of materials, the difference between structures and materials becomes even more elusive. One possible differentiator is </span><span>the presence of boundary: the material itself has no boundaries, but rather may be considered as a material point in the structure.<span class="apple-converted-space"><em><span> </span></em></span></span><span>This point is certainly debatable, your insights will be greatly appreciated.</span></p>
<p><strong><span>Structural Mechanics</span></strong>
</p><p><span>Structural mechanics <span>computes </span><span>deformations<span>,<span class="apple-converted-space"> </span></span>deflections<span>, and </span>stresses<span> or stress resultants within structures. Despite the complexity of a system, the structure, such as the modern aircraft, can be modeled using one or more typical components as listed in Figure 1. I</span></span>f all three dimensions of a component are of similar size, it can be called a 3D structure; if one dimension is much smaller than the other two dimensions, it can be called a plate or shell; if two dimensions are much smaller than the 3rd dimension, it can be called a beam. Many models have been developed for these structural components. The classical ones are Cauchy elasticity for 3D bodies, Kirchhoff-Love model for plates/shells, and Euler-Bernoulli model for beams. Plate/shell models can be considered as 2D models because the unknowns are functions of the two in-plane coordinates and beam models can be considered as 1D models because the unknowns are functions of the axial coordinate only. To this end, beams/plates/shells can be collectively called dimensionally reducible structures as the models of these structural components are reduced from the original 3D model.</span></p>
<p><span><img src="http://imechanica.org/files/StructuralComponents_0.png" alt="" width="682" height="432" /></span></p>
<p>Figure 1. Typical structural components</p>
<p><span>Each model contains three sets of equations including kinematics, kinetics, and constitutive relations (see Figure 2), among which only the constitutive relations change for different materials used to make the structure. </span><span>For composites, the stiffness matrix could be fully populated. <span>The task to predict the constitutive models is usually called structural modeling. </span>3D properties in terms of Young’s moduli, Poisson’s ratios, and shear moduli, could be obtained either experimentally or through a micromechanics calculation. For isotropic homogeneous structures, 3D material properties are direct inputs for structural analysis using solid elements, and these properties combined with geometric characteristics of the structure can be used for plate/shell/beam elements with the structural stiffness obtained based on a priori assumptions such as the Euler-Bernoulli assumptions for beams. However, such straightforwardness does not exist for structures featuring anisotropy and/or heterogeneity. Many refined assumptions, such as higher-order assumptions, zigzag assumptions, layerwise assumptions, have been introduced to better capture the kinematics along the smaller dimensions of the structure, e.g. the thickness of a plate/shell. Formal asymptotic method (FAM) can be used to derive structural models by substituting an assumed asymptotic expansion of 3D displacements into the governing equations of the original 3D model. Variational asymptotic method (VAM) invented by Prof. Berdichevsky (currently at Wayne State) can also be used to derive structural models without a priori assumptions by performing an asymptotic analysis of a functional governing the original 3D model.</span><span> </span><span> The VAM-based beam theory developed by Prof. Hodges and his co-workers has provided a rigorous yet practical tool called <a href="http://analyswift.com/products/vabs-cross-sectional-analysis-tool-for-composite-beams/">VABS</a> for modeling composite blades in both helicopter and wind turbine industry. </span></p>
<p class="MsoNormal"> </p>
<p> <img src="http://imechanica.org/files/structuraltheory.png" alt="" width="749" height="464" /></p>
<p> Figure 2. Basic equations of the classical models for 3D bodies, plates/shells, and beams.</p>
<p><strong><span>Micromechanics</span></strong><br /></p><p class="MsoNormal"><span>Micromechanics focuses on creating </span><span>an equivalent homogeneous material for heterogeneous materials with constituents</span><span> distinguishable at the continuum scale. Usually a representative volume element (RVE) is chosen to describe the microstructure. </span><span>Its first aim is to predict the effective macroscopic propertie</span><span>s of heterogeneous materials. This step is commonly termed homogenization, and many early models were developed solely for this purpose. Homogenization can be used either for virtual materials characterization, i.e., simulating the overall material response under relatively simple loading conditions, or constitutive modeling, where the complete set of effective material properties are computed as inputs for the structural analysis to predict the macroscopic behavior. The second aim of micromechanics is to predict the local fields, such as stress and strain fields, within the microstructure from the macroscopic behavior. This step is commonly termed dehomogenization or localization, and is critical for effectively evaluating the strength and failure of heterogeneous materials. Dehomogenization processes are usually more demanding than homogenization as the local fields are particularly sensitive to the microstructural details. </span></p>
<p><strong><span>Concept of Structure Genome</span></strong><br /></p><p class="MsoNormal"><span>A genome serves as a blueprint for an organism's growth and development. When we use the word genome in non-biological contexts, it can be used to term a fundamental building block toward a larger purpose. According to this, we can define Structure Genome (SG) as the fundamental building block of the structure to emphasize the fact that it contains all the constitutive information needed for a structure the same fashion as the genome contains all the intrinsic information for an organism's growth and development.</span></p>
<p><strong><span>SG for 3D Structures</span></strong><span><strong> </strong></span>
</p><p><span>For 3D structures, SG serves a similar role as RVE. However, there are some difference, see Figure 3. For a structure made of a material featuring 1D heterogeneity (e.g. binary composites made of two alternating layers), SG will be a straight line with two segments denoting corresponding phases as one can mathematically repeat this line in plane to build the two layers of the binary composite, then repeat the binary composite out of plane to build the entire structure. For a structure made of composites featuring 2D heterogeneity (e.g. continuous unidirectional fiber reinforced composites), the SG will be 2D, and for a structure made of composites featuring 3D heterogeneity (e.g. particle reinforced composites), the SG will be 3D. The effective properties should remain 3D regardless of the dimensionality of SG because this is what is required for the 3D structural analysis. For example, for linear elastic analysis, one can obtain the complete 6x6 stiffness matrix from analysis over the 1D SG of the binary composite. Clearly, SG uses the lowest dimension, thus highest efficiency, to describe the heterogeneity, while RVE dimension is usually determined by heterogeneity and what type of properties required for the structural analysis. A 3D RVE is usually required for obtaining the full set of effective properties for 3D structural analysis even if the material is not heterogeneous along all three directions.</span></p>
<p class="MsoNormal"><span><img src="http://imechanica.org/files/SG43DStructures.png" alt="" width="691" height="460" /></span></p>
<p class="MsoNormal"><span>Figure 3. Structure genome for 3D structures</span></p>
<p><strong><span>SG for Dimensionally Reducible Structures</span></strong><br /></p><p class="MsoNormal"><span>SG also allows direct connection with the analysis for dimensionally reducible structures. For example, the structural analysis of slender (beam-like) structures can use beam elements (Figure 4). If the beam has uniform cross-sections, the SG is the 2D cross-sectional domain as we can extrude the cross-section along the beam reference line to build the structure. This inspires a new perspective toward the beam theory, an important topic in structural mechanics. If we consider the beam reference line as a 1D continuum, every material point of this continuum has a 2D cross-section as its microstructure. In other words, constitutive modeling for beams can be effectively viewed as a specific application of micromechanics. If the beam is also heterogeneous in the spanwise direction, we need a 3D SG to describe the microstructure of the 1D continuum, the behavior of which is governed by the 1D beam analysis.</span></p>
<p class="MsoNormal"> <img src="http://imechanica.org/files/SG4Beams.png" alt="" width="666" height="460" /></p>
<p class="MsoNormal"><span>Figure 4. Structure genome for beams</span></p>
<p class="MsoNormal"><span>If the structural analysis uses plate/shell elements, SG can also be chosen properly. For illustrative purpose, typical SGs of plate-like structures are sketched in Figure 5. If the plate-like structures feature no in-plane heterogeneities such as those assumed in lamination theories, the SG is a material line along the thickness direction with each segment denoting the corresponding layer. For a panel with heterogeneity in one of its in-plane directions, for example a sandwich panel with a core corrugated in one direction, the SG is 2D. If the panel is heterogeneous in both in-plane directions, such as a stiffened panel with stiffeners running in both directions, the SG is 3D. Despite of different SG dimensions, what we want out of the constitutive modeling is structural properties for the corresponding structural analysis (such as A, B, D matrices for the classical plate theory) and relations to express the original 3D fields in terms of the global behavior (e.g. moments, curvatures, etc.) obtained from the plate/shell analysis. We know that theories of plates/shells traditionally belong to structural mechanics, but the constitutive modeling of these structures can be treated as special micromechanics applications using the SG concept. For a plate/shell-like structure, if we consider the reference surface as a 2D continuum, every material point of this continuum has the SG as its microstructure. Beam/plate/shell theory constructed using the SG concept also provides a systematic way to handle buildup structures which are prevalent in engineering systems as long as they externally look like beams/plates/shells.</span></p>
<p> <img src="http://imechanica.org/files/SG4Plates.png" alt="" width="744" height="456" /></p>
<p><span> Figure 5. Structure genome for plates</span></p>
<p class="MsoNormal"><span>For periodic or partially periodic structures, it is easy to identify the SG as just described for 3D structures, beams, plates, and shells. However, for real structures which are aperiodic, it is up to the analysts to determine what will be the fundamental building block of the structure representative enough to obtain the constitutive relations, which is usually done in practice.</span></p>
<p><strong><span>Principle of Minimum Information Loss (PMIL)</span></strong><br /></p><p class="MsoNormal"><span>SG serves as the fundamental building block of a structure, no matter whether it is a 3D structure, beam, plate, or shell. For SG to not merely remain as a concept, we need to develop a theory necessary to govern SG so that there is a two-way communication between microstructural details and structural analysis: information from microstructure can be rigorously passed to structural analysis to predict the structural performance and information from structural analysis can be passed back to predict the local fields within the microstructure for failure prediction. We can develop such a theory using the principle of minimum information loss (PMIL) to minimize the loss of information between the original structure with microscopic details and the macroscopic structural model in the structural analysis. For elastic behavior, this can be achieved by minimizing the difference between the strain energy of the materials stored in SG and that stored in the structural model of structural analysis. It is noted that we use the term "microstructure'' and "microscopic details'' in a loose sense. Any details explicitly existing in SG but not in the macroscopic structural model are generally termed microscopic details in this writing. The basic idea of PMIL is briefly illustrated by deriving the classical plate theory starting from 3D elasticity showing in Figure 6. </span></p>
<p class="MsoNormal"><img src="http://imechanica.org/files/Principle%20of%20Minimum%20Information%20Loss_2.png" alt="" width="800" height="1000" /></p>
<p class="MsoNormal">Figure 6. Principle of minimum information loss illustrated by deriving the classical plate theory</p>
<p><strong><span>Discussions</span></strong><br /></p><p class="MsoNormal"><span>MSG provides a possible way to unify constitutive modeling for structures and materials as SG enables the possibility to treat constitutive modeling for beams/plates/shells/buildup structures as special applications of micromechanics. Note that the thought process of MSG is not new and is analogous to the idea of sub-structuring or super-element. MSG provides a rigorous approach to link models across scales based on the homogenization and dehomogenization concepts of micromechanics. As showing in Figure 7, a line element in the global analysis could respond to a box beam made of four laminated walls, a surface element could correspond to a sandwich panel with laminated facesheets and corrugated core. MSG provide a rigorous approach to compute the constitutive models for the line and surface elements based on the local structural details described by the Structure Genome. </span></p>
<p class="MsoNormal"><span><img src="http://hypersizer.com/img/High-Speed-Aircraft5-PanelConcepts_000.GIF" alt="" width="650" height="510" /> </span></p>
<p class="MsoNormal"><span>Figure 7: Sub-structuring for sizing a sample aircraft (Figure linked from Hypersizer.com) </span></p>
<p class="MsoNormal"><span>Many points presented above are certainly debatable and many of you have worked extensively in both micromechanics and structural mechanics. I am looking forward to your comments. MSG has been implemented into a general-purpose constitutive modeling code called SwiftComp, which is available in the cloud at <a href="https://cdmhub.org/resources/scstandard">https://cdmhub.org/resources/scstandard</a> for interested users to try.<br /></span></p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"><span>Reference: </span></p>
<p class="MsoNormal"><span><span>1.<span> </span></span><span>Yu, W.</span><span>: “Structure Genome: Fill the Gap between Materials Genome and Structural Analysis,” </span><em><span>Proceedings of the 56th Structures, Structural Dynamics, and Materials Conference</span></em><span>, Kissimmee, Florida, Jan. 5-9, 2015.</span> (<a href="https://cdmhub.org/resources/605">pdf</a>)</span></p>
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</div></div></div>Wed, 30 Sep 2015 23:54:07 +0000Wenbin Yu18928 at http://imechanica.orghttp://imechanica.org/node/18928#commentshttp://imechanica.org/crss/node/18928Composites Simulation Workshop
http://imechanica.org/node/18856
<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-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><span>Join the Composites Design and Manufacturing HUB for the 2015 Composites Simulation Workshop at Purdue University. Experience the first Composites Simulation Fair with commercial software providers in an open exhibit format. Overview the fundamentals of composites simulation; experience state-of-the-art composites simulation software; hear expert, cutting-edge advances in strength, fatigue and virtual allowables modeling from academic, industry and commercial software experts. Also featured is an extensive hands-on SwiftComp workshop through cdmHUB, a general-purpose multi-scale composites modeling software, recently developed and commercialized by Purdue. </span></p>
<p><span> To register, please go to<a href="http://www.conf.purdue.edu/cdmhub"> www.conf.purdue.edu/cdmhub</a>. </span></p>
<p><span>Workshop resources will be made available at <a href="https://cdmhub.org/members/groups/workshop2015">cdmhub.org/members/groups/workshop2015</a>.</span></p>
<p> </p>
</div></div></div>Wed, 16 Sep 2015 19:43:31 +0000Wenbin Yu18856 at http://imechanica.orghttp://imechanica.org/node/18856#commentshttp://imechanica.org/crss/node/18856Micromechanics Simulation Challenge Level I Initial Results Available
http://imechanica.org/node/18561
<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-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><span>The initial results of level I of micromechanics simulation challenge have been compiled into a report, which is available at </span><span><span><a href="https://cdmhub.org/resources/948">https://cdmhub.org/resources/948</a>.</span></span><span> </span><span>Results for various composites including iber reinforced composites, particle reinforced composites, laminates, woven composites, short fiber composites from several readily available micromechanics simulation tools include MAC/GMC, MAC/HFGMC, FVDAM, MDS, DIGIMAT, SwiftComp are compiled. The accuracy and efficiency of each tool are compared with 3D FEA of RVE with periodic boundary conditions using either ABAQUS or ANSYS. Comments will be appreciated. it is a live report and will be constantly revised and updated by inputs from the community. All the data generating the report are hosted in a live database entitled <a href="https://cdmhub.org/members/project/mmsimulationchalleng/view">Micromechanics Simulation Challenge</a> at cdmHUB. </span><span>This will serve as a reference for those who want to learn about the readily available homogenization tools, most importantly from the perspective of different models' predictive capabilities.</span></p>
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</div></div></div>Wed, 08 Jul 2015 16:44:29 +0000Wenbin Yu18561 at http://imechanica.orghttp://imechanica.org/node/18561#commentshttp://imechanica.org/crss/node/18561IACMI Indiana Starts Hiring
http://imechanica.org/node/18456
<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-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Purdue University is developing the composite virtual factory HUB (cvfHUB), a cutting-edge Cyber infrastructure platform for delivering integrated and validated commercial software tools to the Institute for Advanced Composites Manufacturing Innovation (IACMI), the fifth NNMI. This platform provides predictive capabilities through simulation and modeling to transform composites manufacturing. We are looking for highly motivated, creative, and innovative professionals to join us in this exciting and fast-paced effort. For the first phase, we are hiring multiple software engineers, validation engineers, and application engineers. Please find more details at <a href="https://cdmhub.org/members/1582/blog/2015/06/iacmi-indiana-starts-hiring">https://cdmhub.org/members/1582/blog/2015/06/iacmi-indiana-starts-hiring</a>.</p>
</div></div></div>Tue, 16 Jun 2015 11:00:37 +0000Wenbin Yu18456 at http://imechanica.orghttp://imechanica.org/node/18456#commentshttp://imechanica.org/crss/node/18456Share/run engineering simulation codes in the cloud
http://imechanica.org/node/18116
<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-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/10408">cloud comuting</a></div><div class="field-item odd"><a href="/taxonomy/term/10409">cyberinfrastructre</a></div><div class="field-item even"><a href="/taxonomy/term/10410">cdmHUB.org</a></div></div></div><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>I know the mechanics community have many codes to share. If you have developed engineering software including legacy Windows codes or linux codes, you can easily publish your code in the cloud and have it run on any devices including smart phones through cdmHUB.org. The codes could be simple codes you wrote for your dissertation or comprehensive commerical package like ABAQUS or ANSYS. You don't have to change your code, no source codes are needed. All you need to do is to upload your executable through a very straight forward way which only takes a few minutes. And the best of all, it is free and y</span><span>ou control your own code.</span><span> Please explore<span class="apple-converted-space"> </span></span><span><a href="https://www.linkedin.com/redirect?url=https%3A%2F%2Fcdmhub%2Eorg%2F&urlhash=2b0c&_t=tracking_anet" target="blank"><span>https://cdmhub.org/</span></a></span><span class="apple-converted-space"><span> </span></span><span>for more details. We launch this platform for encouraging collaborations around composites simulations. Your comments, suggestions and contributions will be greatly appreciated. </span></p>
</div></div></div>Sat, 28 Mar 2015 04:06:49 +0000Wenbin Yu18116 at http://imechanica.orghttp://imechanica.org/node/18116#commentshttp://imechanica.org/crss/node/18116Micromechanics Simulation Challenge - Level 1
http://imechanica.org/node/17842
<div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/18">micromechanics</a></div><div class="field-item odd"><a href="/taxonomy/term/10309">computer software</a></div></div></div><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>For the purpose of establishing the best practice for homogenization and dehomogenization needed in composites design and manufacturing, </span><a href="https://cdmhub.org/">cdmHUB </a>launches the Micromechanics Simulation Challenge. After incoporating comments <span>from academia, industry and commercial software providers, we have finalized the final draft for Level 1 problems, which is attached here with more details can be at </span><a href="https://cdmhub.org/resources/665">https://cdmhub.org/resources/665</a><span>. You are welcome to work on these problems using whatever micromechanics codes you are familiar with and report the results on cdmHUB. If you are teaching a class on micromechanics, or multiscale modeling, feel free to use these problems as homework problems for students. The cdmHUB team thanks your attention and possible contribution to this effort in advance!</span></p>
<p><span> </span></p>
<p><span>Wenbin</span></p>
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<tr class="odd"><td><span class="file"><img class="file-icon" alt="" title="application/pdf" src="/modules/file/icons/application-pdf.png" /> <a href="http://imechanica.org/files/Micromechanics%20Challenge%20Specification%20-%20Level%201.pdf" type="application/pdf; length=673767">Micromechanics Challenge Specification - Level 1.pdf</a></span></td><td>657.98 KB</td> </tr>
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</div></div></div>Tue, 27 Jan 2015 20:55:03 +0000Wenbin Yu17842 at http://imechanica.orghttp://imechanica.org/node/17842#commentshttp://imechanica.org/crss/node/17842cdmHUB.org: Online Composites Community of the Future
http://imechanica.org/node/17528
<div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/5863">cloud computing</a></div><div class="field-item odd"><a href="/taxonomy/term/934">Composites</a></div></div></div><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 thought this might be of interest for some imechanicans, particularly those who work on composites (anisotropic and/or heterogeneous materials). Sorry if it sounds a bit infomercial. </p>
<p>Imagine a youtube-like environment for you to deploy a cloud version of your code without any change to your original code. Your research code can be immediately shared with the global community. </p>
<p>Imagine a place you can find all the computer tools for composites simulation including comprehensive commercial codes like ABAQUS to research codes written by graduate students who are working on their theses.</p>
<p>Imagine having fingertip access to composites simulation tools anywhere, anytime, on any device including smart phones. Tools that are not java applets but real commercial codes connected to HPC resources in the cloud.</p>
<p>Would you have questions about results or underlining models, imagine being able to ask subject matter experts and world leading researchers 24/7 and being able to add your voice to the rest of the community.</p>
<p>Imagine a new way of publishing: the equations in your paper are directly connected to the computer codes in the same place so that others can easily understand and adapt your research.</p>
<p>Imagine going a tradeshow of composites simulation software where you can try all the potential tools at your own pace using your own problems. You won’t get just the sales pitch but can have access to all the information about the software, including reviews from others and evaluations from experts. Plus no travel is needed!</p>
<p>At Purdue, we are launching the Composites Design and Manufacturing HUB (cdmHUB.org). Powered by the cyberinfrastructure of HubZero, supported by the collective wisdom and knowledge of the community, and sponsored by our visionary industrial leaders, cdmHUB will:</p>
<ul><li>Provide a single site for review of all composites simulation tools</li>
<li>Convene composites experts to establish a simulation tool maturity level (TML)</li>
<li>Identify opportunities and mechanisms for integration of simulation tools</li>
<li>Identify needs for new tool innovations</li>
<li>Support the growth and maturation of new simulation tools</li>
<li>Support data bases necessary for verification and validation of simulation tools</li>
<li>Support the development of intellectual talent in simulation tool use and new tool development</li>
<li>Facilitate pervasive and accelerated learning of composites</li>
<li>Establish and promote “Best Practices” for composites simulation tools</li>
</ul><p>All you need is a web browser connected to cdmHUB.org. <span>As we are still in development stage, any of your comments will be greatly appreciated and help guide the future of cdmHUB. Please provide your feedbacks either here or through <a href="https://cdmhub.org/members/1230/blog/2014/11/online-composites-community-of-the-future">cdmHUB.org</a>.</span></p>
<p> </p>
<p> </p>
</div></div></div>Fri, 21 Nov 2014 12:10:58 +0000Wenbin Yu17528 at http://imechanica.orghttp://imechanica.org/node/17528#commentshttp://imechanica.org/crss/node/17528Micromechanics Simulation Challenge
http://imechanica.org/node/17220
<div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/18">micromechanics</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>As the importance of micromechanics is increasingly realized in composites design & manufacturing at the industry level, <a href="https://cdmhub.org/">cdmHUB </a>is launching a <a href="https://cdmhub.org/members/1582/blog/2014/09/micromechanics-challenge">Micromechanics Simulation Challenge</a> for the purpose of establishing the best practices for homogenization and dehomogenization needed in composites design and manufacturing. The Micromechanics Simulation Challenge consists of 3 levels with increasing complexities, each with benchmark-type problems to access the strengths and trade-offs of existing micromechanics codes. We are currently defining level 1 problems and soliciting comments from micromechanics tool developers and other interested parties. Any inputs from the imechanica community will be greatly appreciated. More details can be found at: <a href="https://cdmhub.org/members/1582/blog/2014/09/micromechanics-challenge">https://cdmhub.org/members/1582/blog/2014/09/micromechanics-challenge</a>. </p>
</div></div></div>Tue, 23 Sep 2014 18:13:33 +0000Wenbin Yu17220 at http://imechanica.orghttp://imechanica.org/node/17220#commentshttp://imechanica.org/crss/node/17220cdmHUB: Publish and Run Composites Simulation Tools In the Cloud
http://imechanica.org/node/17006
<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-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/9978">cdmHUB</a></div><div class="field-item odd"><a href="/taxonomy/term/934">Composites</a></div><div class="field-item even"><a href="/taxonomy/term/1117">design</a></div><div class="field-item odd"><a href="/taxonomy/term/269">manufacturing</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>We recently launched the Composites Design and Manufacturing HUB (<a href="https://cdmhub.org/">cdmHUB.org</a>), a community-driven, collaborative platform that has the unique capability to let users to freely <strong>publish</strong> and <strong>run</strong> simulation codes in the cloud in addition to all the social network functionalities (blogging, questions/answers, groups, etc.). <a href="https://cdmhub.org/">cdmHUB</a> is build upon the same cyberinfrastructure as <a href="https://nanohub.org/">nanoHUB</a>, a site praised in Materials Genome Initiative as a good example for open innovation and collaboration. This platform removes the need of installation of the codes on client machines and the need of high end computing resources as it is linked with HPC resources in the cloud. Basically, one can run huge engineering simulations using mobile devices. In additional to computer codes, cdmHUB also host many other types of resources such as animations, lecture notes, oneline presentations, publications, ect. With the collective wisdom and knowledge of the community, we plan to
</p><ul><li>Provide a single site for review of all composites simulation tools</li>
<li>Convene composites experts to establish simulation tool maturity level (TML)</li>
<li>Identify opportunities and mechanisms for tool integration</li>
<li>Identify needs for new tool innovations</li>
<li>Support the growth and maturity of new simulation tools</li>
<li>Support data bases necessary of verification and validation of simulation tools</li>
<li>Support the development of intellectual talent in simulation tool use and development</li>
</ul><p><span><span>We are still in the stage of exploring the functionalities of <a href="https://cdmhub.org/">cdmHUB</a>. For example, one can establish their research group online with discussions, wikis, resources, and computer codes accessbile only to their group memebers. Any comments/suggestions are greatly appreciated. We welcome your participation and contribution in any format. </span></span></p>
</div></div></div>Sat, 09 Aug 2014 12:48:27 +0000Wenbin Yu17006 at http://imechanica.orghttp://imechanica.org/node/17006#commentshttp://imechanica.org/crss/node/17006Help compile list of available micromechanics codes
http://imechanica.org/node/16965
<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-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/18">micromechanics</a></div><div class="field-item odd"><a href="/taxonomy/term/9991">codes</a></div></div></div><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>Computer simulations will be used more and more for composites design and manufacturing. Before an engineer can simulate, there are at least two questions: what are the tools available and which one works for my problem. Thus, as a start,<span class="apple-converted-space"> </span><a href="https://cdmhub.org/"><span>cdmHUB </span></a>plan to compile a list of micromechanics codes for the community, including commercial codes, public domain codes, or research codes. To make the list as complete as possible, we need your help. If you know some micromechanics codes, please provide the name of the tool and contact information (url will be sufficient). We will also appreciate a brief describe of your experience with it if you have used some of these codes. This question is originally posted on <a href="https://cdmhub.org/answers/question/34"><span>cdmHUB.org</span></a>. You can provide feedback here or at<span class="apple-converted-space"> </span><span><a href="https://cdmhub.org/">cdmHUB.org</a></span>.</span></p>
</div></div></div>Thu, 31 Jul 2014 17:12:52 +0000Wenbin Yu16965 at http://imechanica.orghttp://imechanica.org/node/16965#commentshttp://imechanica.org/crss/node/16965Run GEBT online within a web browser
http://imechanica.org/node/16924
<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-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/4431">composite beam</a></div><div class="field-item odd"><a href="/taxonomy/term/371">nonlinear</a></div><div class="field-item even"><a href="/taxonomy/term/9978">cdmHUB</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>One can now run <a href="https://cdmhub.org/resources/gebt">GEBT (Geometrically Exact Beam Theory)</a>, a general-purpose nonlinear composite beam solver, online within a web browser through <a href="https://cdmhub.org/">cdmHUB.org</a>. Users do not have to install the code on their own machine. And users can access to immediate support if run into any questions. You are welcome to try out the code and let me know any of your questions. </p>
</div></div></div>Tue, 22 Jul 2014 19:30:51 +0000Wenbin Yu16924 at http://imechanica.orghttp://imechanica.org/node/16924#commentshttp://imechanica.org/crss/node/16924Please recommend a good mechanics of material book
http://imechanica.org/node/16658
<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-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>
I am teaching mechanics of materials to sophomore. However, our students do not have a separate static course. They get a some exposure to free body diagrams in particle dynamics. I am currently using the book by Gere and Goodno. But I found that both the teaching and learning experience were not good. Thanks a lot in advance for your suggestions!
</p>
<p>
</p>
<p>
Wenbin
</p>
</div></div></div>Fri, 23 May 2014 14:14:48 +0000Wenbin Yu16658 at http://imechanica.orghttp://imechanica.org/node/16658#commentshttp://imechanica.org/crss/node/16658Three ways to derive the classical plate model
http://imechanica.org/node/12283
<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-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/6288">plate theory</a></div><div class="field-item odd"><a href="/taxonomy/term/7309">variational asymptotic method</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p class="MsoNormal">
<span>Attached is part of my lecture notes for a graduate structural mechanics. In<br />
the notes, we derived the classical plate theory, which is also called<br /></span><span>the Kirchhoff plate theory</span><span>, in three ways: Newtonian method, variational<br />
method, and variational asymptotic method, using 3D elasticity theory as the<br />
starting point. The self-contradictions of Kirchhoff assumptions and plane-stress assumptions used in both<br />
Newtonian method and variational method are clearly pointed out. The<br />
variational asymptotic method does not rely on any ad hoc assumptions, ending<br />
in a self-consistent theory. It can be considered as a theoretical<br />
tutorial for <a href="http://hifi-comp.com/vapas.aspx">VAPAS</a>, a general-purpose tool for modeling composite plates. </span>
</p>
<p>
<font face="Times New Roman" size="3"><br /></font>
</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>
<tbody>
<tr class="odd"><td><span class="file"><img class="file-icon" alt="" title="application/pdf" src="/modules/file/icons/application-pdf.png" /> <a href="http://imechanica.org/files/plate.pdf" type="application/pdf; length=209520" title="plate.pdf">plate.pdf</a></span></td><td>204.61 KB</td> </tr>
</tbody>
</table>
</div></div></div>Fri, 13 Apr 2012 04:20:53 +0000Wenbin Yu12283 at http://imechanica.orghttp://imechanica.org/node/12283#commentshttp://imechanica.org/crss/node/12283Three-ways to derive the Euler-Bernoulli-Saint Venant Beam Theory
http://imechanica.org/node/12188
<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-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/464">bending</a></div><div class="field-item odd"><a href="/taxonomy/term/469">torsion</a></div><div class="field-item even"><a href="/taxonomy/term/667">beams</a></div><div class="field-item odd"><a href="/taxonomy/term/6055">vabs</a></div><div class="field-item even"><a href="/taxonomy/term/7309">variational asymptotic method</a></div><div class="field-item odd"><a href="/taxonomy/term/7310">extension</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><font face="Times New Roman" size="3"><br /></font></p>
<p class="MsoNormal">
<span>After having taught graduate structural mechanics for several years, I am finally<br />
able to write down my lecture notes (attached) for teaching the beam theory. In<br />
the notes, we formulated the complete classical beam model<br />
(extension/torsion/bending in two directions), which is also called<br />
Euler-Bernoulli-Saint beam theory, in three ways: Newtonian method, variational<br />
method, and variational asymptotic method, using 3D elasticity theory as the<br />
starting point. Many self-contradictions of the various assumptions used in both<br />
Newtonian method and variational method are clearly pointed out. The<br />
variational asymptotic method does not rely on any ad hoc assumptions, ending<br />
in a self-consistent theory. Many confusion points (at least for myself when I was an undergraduate student) about the beam theory have been clarified. Deriving<br />
Timoshenko model was left as a homework problem. It can be considered as a theoretical<br />
tutorial for <a href="http://hifi-comp.com/vabs.aspx">VABS</a>, a tool for blade modeling extensively used in helicopter and<br />
wind turbine industries. </span>
</p>
<p><font face="Times New Roman" size="3"><br /></font></p>
<p class="MsoNormal">
<span> </span>
</p>
<p><font face="Times New Roman" size="3"><br /></font></p>
<p class="MsoNormal">
<span>Any<br />
comments/critiques are welcome.</span>
</p>
<p><font face="Times New Roman" size="3"><br /></font></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>
<tbody>
<tr class="odd"><td><span class="file"><img class="file-icon" alt="" title="application/pdf" src="/modules/file/icons/application-pdf.png" /> <a href="http://imechanica.org/files/EulerBernoulli3D.pdf" type="application/pdf; length=258159" title="EulerBernoulli3D.pdf">EulerBernoulli3D.pdf</a></span></td><td>252.11 KB</td> </tr>
</tbody>
</table>
</div></div></div>Wed, 28 Mar 2012 16:11:37 +0000Wenbin Yu12188 at http://imechanica.orghttp://imechanica.org/node/12188#commentshttp://imechanica.org/crss/node/12188