When we have stress, say in x direction, due to poisson effect, we get strain in y and z directions.
What is the reason that associated stress does not develop due to this strain in y and z directions? Is it due to the fact that there is no restraint to this strain, something similar to when free thermal expansion does not result in stress?
I am trying to start studying HIFU (high intensity focused ultrasound) absorption mechanisms and modeling methods, specially for clinical applications(absorption in tissue). But I cant find any straightforward article in this field.Would you please help me on this.
With great Thanks.
I need help in executing ANSYS user programmable feature (UPF), specifically subroutine userpr (changing element pressure information) for my 2D model. I have read the manual but don't understand the subroutine program structure (attached below). Can someone kindly explain how can I activate and run the subroutine?
"Subroutine Userpr text file":
Do yo know if there is some software to calculate if a dielectric solid is broken down when is applied a electrical potential? For example, I was using ANSYS, but I only can calculate an electrostatic analysis... So I can calculate the electric field distribution inside the solid. In this case the electrical fiel is concentrated only near the electrode, and I know that in this area the electric field is bigger than the breakdown electric field... But in the experiments you can see that the breakdown in produced in all of the solid because the potential is transmitted inside the solid step by step (because cracks are produced) when the electric field is bigger than the breakdown electric field
I hope that somebody can help us!
For my graduation work (student at the Delft university of Technology, The Netherlands), I am trying to model the aeroelastic behavior of a wind turbine rotor. For this end I use an Abaqus model of a wind turbine blade (which is a composite structure with different fiber layers and corresponding orientation). The aerodynamic force is calculated by a BEM code (Blade Element Momentum theory), which is a simplified engineering aerodynamic code: fast but still quite good. Using CFD to calculate the loads is out of the question since it requires far too much time to calculate.
In joint material interface between elastic and elastic-plastic material, how can we show the continuity of displacement theoretically?It must be continuous and compatible of deformation in practical case.Could anyone help me to understand this answer?
Hi, folks! I'm a new user of Abaqus. Please can you help me with remesh, ALE remesh technique in Abaqus/CAE. May be you have any example in Abaqus/CAE. If you have any, plese me on email@example.com.
FIRST TIME EVER ON THIS SITE, IT IS GREAT!
WELL, IF YOU HAVE QUESTIONS TO ASK JUST SHOOT, I AM BEGGINING AN SPECIALIZATION IN STRENGHT OF MATERIALS AND I MAY KNOW SOME THINGS.
AS PER ME, I HAVE A QUESTION. I AM WORKING ON CURVED BEAMS AND I HAVE A HOLLOW SECTION THAT GENERATES DOUBTS IN ME; I HAVE APPLIED WINKLER SINCE I KNOW IT WILL WORK WELL TAKING INTO ACCOUNT THE THICKNESS OF THE WALLS AND CALCULATING SOME COEFFICIENTS FROM OLD BOOKS OF TIMOSHENKO (THAT SOMEWAY TOLD ME TO APPLY WINKLER, BUT...), SO I WOULD LIKE TO KNOW IF YOU HAVE STUDIED SIMILAR CASES AND THE WAY YOU SOLVE IT.
The ability to control the domain patterns in ferroelectric nanostructures holds promise as a method to tailor physical properties for specific applications. We proposed a new way to control the domain patterns in ferroelectric nanostructures. Desirable domain patterns can be obtained through different surface charges. The surface charges can be supplied by the atomic and molecular adsorbates on the surfaces of ferroelectric nanostructures.
The deadline for abstracts for the 21st Annual Melosh Competition has been extended until January 30. All interested graduate students are encouraged to apply.
This competition for the Best Student Paper in Finite Element Analysis will be held at Duke University on Friday, April 24, 2009. The competition has become one of the premier graduate student events in the broad area of computational mechanics.
Hi, I am using Abaqus.
Need to model simple beam-column connection (with beam elements). Connection should allow rotation but not translation. I am new to Abaqus so please help.
Tried connector section, defined it, but I dont know how to use/apply it.
Hi all .. What are the advantages of XFEM over std FEM other than remeshing ?
Because when ever XFEM is introduced only remeshing alone is highlighted ... Can the experts from this field please list out the other advantages?
All above are in context to Fracture.
thanks in advance.
Molecular dynamics study of effects of sp3 interwall bridging upon torsional behavior of double-walled carbon nanotubeSubmitted by haiyang song on Mon, 2009-01-12 19:58.
I am creating a mesh for a composite material using Fortran by assigning two different material markers for the data. I am able to see the output in tecplot but i would like to set two different colors for the two materials such that i can see the same in tecplot. As of now, i can see just one color for the whole mesh and i cant differentiate where the second material is distributed. Please suggest on how i can see the tecplot with different colors for the two different materials i have used in my .dat file. I am new into using all this so i need the advise. please suggest.
a recent pre-print about the mechanics of plectonemic DNA in extension-rotation experiments (under submission Biophysical Journal)
Journal version: http://www.cell.com/biophysj/abstract/S0006-3495(09)00564-5
Authors: N. Clauvelin, B. Audoly, S. Neukirch
I am krishna working on FE knee joint modeling in ABAQUS. I am beginner to Abaqus
As i have read from the journal papers, I understood that cartilage and meniscus are poroelastic (porous medium).
My axisymmetric model consists of following.
1. Cartilage is modelled with CAX4PH (axisymmetric pore pressure elements)
2. Meniscus is also with the same elements
3.Tibial bone with CAX4 elements.
contact beween two deformable bodies create computational difficulties,
I am using membrane with low stiffness between the cartilage and
Membrane is tied to meniscus and modeled with MAX1 elements.
a recent pre-print concerning the elasticity of a knotted rod (submitted to Journal of the Mechanics and Physics of Solids)
Authors: N. Clauvelin, B. Audoly, S. Neukirch
I have no mechanics background so be gentle. Looking for advice on how to approach this problem:
I have a long, slender, straight beam that is then bent into a curve using wire rope as a tension element between either end. Very similar to an archery bow.
I want the final shape of the beam (specifically the surface away from the radius of curvature) to be a parabola whose vertex is in the center of the beam. The beam will be a constant thickness but varying width. Modulus of Elastisity is assumed constant and there is no yielding in the material (or a thickness that prevents the stress from rising too high is selected).
By varying the width and therefore the moment of inertia, I should be able to follow the parabola.
I am trying to figure out how to call UMAT through the abaqus command. I have a local abaqus licence. How do I get into the command window to type in the commands? I have installed fortran. I am trying to run one of the examples in the manual which gives me the .inp file and .f file. I went through a number of forums and the manual which tells me to use compile_fortran and abaqus make commands. Can someone guide me through the procedure? I am using version 6.7-5.
How to perform post-buckling analysis using ABAQUS correctly?
I have obtained an eigenvalue from a linear analysis using BUCKLE command. The shape from mode 1 is good (tally with the physical experiment).
However, the result from the post-buckling analysis (using IMPERFECTION command and RIKS analysis) has not produced the buckling shape like the mode 1 from the linear analysis.
If you all have any suggestion, please share it with me. Greatly need it.
Can anyone please tell me the constitutive or the 'C' matrix for a linear viscoelastic material model (with no relaxation in bulk)? I have been using the one outlined in the Computaional Mechanics book by Simo and Taylor, but I feel that ANSYS is using a different matrix as my results are different from ANSYS. I could not find details about the 'C' matrix for a viscoelastic material anywhere else. Any links too might be helpful.
Structural and Multidisciplinary Optimization Lab.
University of Florida
Don't know why the post to the journal club won't show up, post it here instead.
In addition to the tissue engineering application, the study on cell mechanics is also motivated by the interest on the mechanotransduction – the process of converting physical forces into biochemical signals and integrating these signals into the cellular responses. I’d like to add this perspective to the discussion. Understanding the mechanotransduction requires the integration of the measured mechanical properties (stiffness, viscoelastic time constants, etc) and the cell biology; thus, it poses a main challenge to the cell mechanics.
My research interest focuses on concrete damage constutitive model and its numerical implementation, performance-based seismic design of bridge structures, variational integrand method and conservative propertied of irreversible process, methmatical base of damage theory .Now I work as a postdoctoral research till Sep. 2009 at Tongji University, P R China. My current research are supported partly by China Postdoc Fund Committee and Shanghai Postdoc Fund Committee.