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bleong

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  1. I tried but it didn't work. I've tried deleting the contact surface itself and it runs through the 0 iteration, remeshes successfully, runs 8 or so iterations, remeshes again, then fails during the element quality check. I then tried to turn off the element quality check but the same error occurred. Rahul, here are the out files. Shape_Opt_04.out Shape_Opt_04_rmsh001.out
  2. Here are both the original and remeshed fem files. Shape_Opt_04.fem Shape_Opt_04_rmsh001.fem
  3. Hi Everyone, I'm performing shape optimization on a part, and I've run into the issue where after about 8-10 iterations the solver stops with the error of excessive element distortion. I've set the REMESH control card to 1 as suggested here: http://www.altairuniversity.com/wp-content/uploads/2015/06/REMESH_opti_control.pdf . However, when I do this the solver does iteration 0, outputs the excessive mesh distortion error, says that I have a feasible design (no stress constraints violated in the original part), gives me the "***** END OF REPORT *****" message, then says it's starting the remesh. It then proceeds to run the remesh on one core (I have 8) and takes forever (it's still running after an hour, but with very little RAM usage). Is this what's supposed to happen or am I doing something wrong? What I don't get is why it now says there is an excessive element distortion on iteration 0. Thanks! **Update: So the remesh finally finished (after about 2 hours) and the solver reloaded, but gave the following error: *** See next message about line 7281 from file: Shape_Opt_04_rmsh001.fem "SURF 2ELFACE" Syntax error(s) found in bulk data 'SURF' card. I have two contact surfaces in the model, not sure if that's the issue, as in the .fem file this line is right near the definition of the contact surface.
  4. Ok yeah now I realize my mistake. Volfrac doesn't exist for shape optimization because that doesn't make sense. I'll do a minimize volume objective.
  5. Thanks for your help! I think the issue was that near where the members meet the mesh strays slightly from the geometry to prevent really thin tetra elements and thus when I use select nodes by geom some nodes don't get selected and so there are patches of unselected nodes within the selected regions. I had been making a desvar for each member I wanted changed but considering my settings for all of them were the same I remade a single desvar containing all of the regions and the solver got past the point where the previous error was. However, now it is giving me: *** ERROR # 1814 *** VOLFRAC response on DRESP1 card 3 is not applied to a topology or free-size domain. I'm doing a minimize volfrac objective with a stress constraint. Is this not allowed for a free-shape optimization? Thanks!
  6. Hi Everyone, I'm trying to fine-tune a topology optimized part using free shape optimization on some of the members. Unfortunately when I run Optistruct, it gives me the following: *** ERROR # 7312 *** DSHAPE card 1 contains 2 disconnected patches. Patch(es) listed below contain too few grids that are likely insufficient for defining a smooth surface/curve. I can't find anything on this error. Also, it doesn't list any "patches" so I'm not even sure where it's having problems. Any advice? Thanks! Size_Opt_Setup
  7. Hi, Thanks for your reply. I've tried the refinement box before, I just can't figure out how to select the elements within the refinement box. Would you be able to provide more details? I'm sorry I've only been using Hyperworks for about a month. Thanks!
  8. Hi Prakash, I've used OSSmooth to export a geometry before, but its not very smooth and creates a very complex geometry when loaded into SolidWorks that is filled with surface errors. Is there any simple way I could use the optimized geometry as a guide for drawing a cleaner part in SolidWorks? Thanks!
  9. Hi Everyone, I've been using Optistruct topology optimization for a project I'm working on and I am satisfied with the results of the optimization. I'm now trying to make a CAD model of the part to simplify the geometry and make it more practical (adding surfaces for bolts to sit on and getting rid of the rough surface created by the mesh and OSSmooth). I'm using Solidworks as my CAD tool and can't seem to find anything about the most efficient ways of doing this. Does anybody have any advice? Thanks!
  10. Hi, I'm trying to refine a tetra mesh around a bolt hole after a topology optimization. OSSmooth only returns a mesh so I don't have any geometry, only tetra elements. I've tried using split elements but it doesn't seem to do anything as well as refine elements which apparently only works on shell elements. Any suggestions?
  11. Hi Everyone, I'm new to Hyperworks and working my way through the tutorials but for some reason I can't seem to see meshes on my parts when I create them. Here's a screenshot of what I can see: No matter how far I zoom in the mesh doesn't appear, and I can only see it when using the "shrink" visualization setting, which appears as below: My graphics card driver should be up to date as I just updated it a few weeks ago. I'm running a Radeon graphics card on Gentoo Linux, and using Hyperworks 14.0 Desktop. Thanks!
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