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  1. cvan42

    Pressure on areas applied in Y axis?

    Flash, good to know about these elements, will give them a try. Kosik, if you get the surface area ( the length of the tab multiplied buy the width of the chamfer) and multiply by the pressure you should get the Y force. When you scope to the surface ANSYS automatically splits the force up...
  2. cvan42

    Stent Crimping

    Jay, If I read it correctly it sounds like you are compressing to crimp diameter, expanding to design diameter, then pulling axially a certain amount. If you cannot constrain one side of the stent to always be restricted axially, there is another way without having to write scripts. Need to...
  3. cvan42

    Pressure on areas applied in Y axis?

    Kosik, it looks like you might need to apply a force. Forces will always be directed in the vector you chose (like Y in your pic), and pressures will always follow perpendicular to the surface it is scoped to. A big difference if those faces rotate as they deform. If those surfaces are...
  4. cvan42

    Stent Crimping

    Jay, Looks good man, it looks like you are applying radial displacements to the inner and outer surfaces. This might be ok if the struts are the same width/thickness. For reference, our design has two different widths of struts around the circumference, so they are going to move differently...
  5. cvan42

    stress at location

    Bram, Have you tried modifying your geometry? When we have this issue we create split lines in SolidWorks to the surfaces of interest in order to scope lines or points.
  6. cvan42

    Convergence issues (force converges, but moment don't)

    Hervandil, Thank you for the update. SHELL208 and 209 have only 3 DOF, but with SHELL181 and 281 you should have all 6 DOF. I'm guessing you have the 181 or 281, so it sounds like there is something else going on. My experience using shell to model large structures and frames is very low...
  7. cvan42

    Convergence issues (force converges, but moment don't)

    Hi Hervandil, Have you tried the stabilize command? In 14.0+ it is an option in the Nonlinear Controls tab. Earlier versions you need a script STABILIZE, CONSTANT (OR REDUCE) ENERGY,1E-5,ANYTIME. In the results it's a good idea to compare stabilze energy to strain energy to make sure the...
  8. cvan42

    Stent Crimping

    Hi Jay, Our group has been working on this type of problem for the last year or so. We are compressing down to crimp dia, then expanding to design diameter. There is a lot that goes into this study. We use all solids and found surface cylinders with the most hyperelastic properties would...
  9. cvan42

    Analyzing Nonlinear Contact Using ANSYS Workbench?

    Chabaain, if you can subscribe to xansys on top of this forum you'd get more rounded information. You can do a search in their archives. This is a very good question, and there is probably some high detail ADPL scripting required to figure this out. If I had more time I'd look into this as...
  10. cvan42

    Type of elements in ANSYS Solidworks

    Chaabain, long time no speaketh. If your company got a seat and keeps maintainence, you can log onto the ANSYS site, login, and go download the element type reference. This reference goes through all the types in detail, and you'd be surprised how many element types there are. Depending on...
  11. cvan42

    Fatigue analysis used ANSYS Workbench

    You could look for published papers online, most places you'll have to pay a small fee to get the pdf. Also, if you're still connected with your university, ask around with the professors and such, although a lot of biomed is on Abaqus. Just go through the help files to find out what data...
  12. cvan42

    New to FEA & ANSYS Workbench - Help Please

    dhray, I believe what is going on is your contact pair isn't near or touching on the first substep and your bowl is taking off to the moon since it's only constrained not to rotate along the axis. Let it run to nonconvergence, look at Solution->Deformation->Total, right click and Evaluate All...
  13. cvan42

    Fatigue analysis used ANSYS Workbench

    Chaabain, The fatigue module needs fatigue data for each material. You could use the standard aluminum and steel, but these will not be even close to the ceramics you are talking about. We're in biomed and working on fatigue of nitinol filter wires during vena cava cycles, and we had a...
  14. cvan42

    Strain Energy in Workbench

    Been working on an extrusion process simulation, and we're interested in the strain energy density of the extruded material, PTFE. Problem is, the model simulates PTFE material extruding against stainless steel bodies along the length of the ID and OD. Also, I assigned SOLID186 brick to the...
  15. cvan42

    ANSYS WB nodal averages of surfaces

    Alex, Thanks for the code, I owe you one. We're simulating curing different stent graft geometries, and this will be a huge help. http://www.bardpv.com/_nonvascular/product.php?p=75 Chad...
  16. cvan42

    ANSYS WB nodal averages of surfaces

    Good Evening, wondering if any of you know how to script the averages of a result across a surface. Normally I'd be hesitant in stress/strain. We're working on simulating an oven and would really like to script average temperatures and fluxes across some surfaces, as min and max don't really...
  17. cvan42

    Modal Analysis: Why high stress/displacement?

    Greg, Stringmaker, Thanks for the insight, will be sure to do more research on forced responses. Knew there's an obvious explanation for this. Chad
  18. cvan42

    Modal Analysis: Why high stress/displacement?

    Good evening, working in Workbench. Been analyzing a small plastic (Valox) gear, and was interested in modes. Where reasonable frequencies are shown in results, 6 modes within 1200 Hz to 1500 Hz, stresses and displacements are unreasonably high, 1.5 e8 PSI with lowest stress 50 KSI. With a...
  19. cvan42

    Force or Pressure

    Like crisb I use pressure heavily. Another aspect to think of, is forces are typically assigned in x,y,z coordinates, and pressures are applied perpendicular to the surface. So, if you have a rod/plate bending or buckling, a pressure load could induce it quicker than force load.
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