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Hello, I have been trying to use tiebreak contact (CONTACT_AUTOMATIC_ONE_WAY_SURFACE_TOSURFACE_TIEBREAK) [Option 9] with the 20 noded Hexahedral solid element (ELFORM 23). When I select the surfaces using the segment set approach- it keeps giving me an error that certain master, slave surfaces have not been not found. Because this didn't work, I then tried defining tiebreak contact using the PARTIDs. But, with this approach the nodes on the middle of the edges don't get selected and only the nodes on the corners are tied. I strongly prefer to use the segment set selection of tiebreak surfaces, and need to know to how to execute this for the 20 noded hexahedral elements. Also another associated issue is that when I use a regular a contact definition between two hex elements and apply a closing/compressive load, there is interpenetration at the middle nodes (i.e. the nodes in the middle of the edge)- which should not occur. Requesting ANSYS personnel to  help figure a solution to these problems on priority. If the model files need to be shared, please advise on who this should be sent to? Thanks  

Hi everyone, I'm looking for a way to include linear viscoelastic behavior in the passive component of the muscles in LS-DYNA. I'm considering either *MAT_MUSCLE (*MAT_156) or *MAT_SPRING_MUSCLE (*MAT_S15). Ideally, I'd like to model the passive response using a linear viscoelastic formulation (such as a Prony series) while keeping the active muscle behavior unchanged. Does anyone know if this is possible with either of these material models? Or is there another way to achieve this, such as adding a separate viscoelastic element in parallel? I'd appreciate any suggestions or examples. Thanks!

I need to access the current element nodal coordinates in the user defined material subroutine to be able to calculate the Jacobian for the regularization scheme I am implementing.  Any help on how to access this data would be very much appreciated.  Thanks.

Hello everyone , I am using ansys - workbench - ls dyna and im trying to mesh my model . Any idea why these white lines are far from the body ? They appear only on LS DYNA - model and not in the geometry . When im meshing is causing the body to show waves on the surface.

Hi,I'm trying to download Ls-PrePost on Windows using the following link provided by Ansys:https://ftp.lstc.com/anonymous/outgoing/lsprepost/It says "Access Denied" and I don't know why, since it worked until 2 months ago. What can I do??Thankss

I have configured ANSYS RSM, I submit the job from laptop to PC, it successfully finishes solve on PC and wirtes output files (d3plot) in the selected folder on PC, but it does not transfer the files back to the laptop? Any ideas how to resolve this issue?

Hi, Is there a way to access the current integration point number from the user-defined material subroutine?  I see in appendix R that it is accessible to the user-defined cohesive materials model subroutines. However, I do not see how to access it in the standard user-defined material models.  I need to compute higher order derivatives of the shape functions as part of a regularization scheme at each integration point for my material model.  Thanks!  

Hi, I am a PhD candidate in Mechanical Engineering at Purdue University implementing a user defined material (umat41) for LS-DYNA MMALE simulations of granular flow. Ansys Support (Kristy, ACE Customer Operations) replied on September 21, 2026 that academic support is provided through this forum, which is why I am posting here. I understand the ftp.lstc.com/objects credentials cannot be shared. Following the earlier thread "Request for access to dyn21.f file for research project", could an Ansys employee download the matching usermat package and send it to me directly? The Download Center carries the LS-DYNA solver binaries but not the usermat packages. Solver: lsdyna_dp_mpp.e from Purdue's Ansys 2026 R1 installation, revision R16.1.1-32-g1f25c69f9c, Linux x86_64, MPP, double precision, SSE2, Intel Fortran 19.0, Intel MPI 2018.3.222, sharelib. Expected package name: ls-dyna_mpp_d_R16_1_1_x64_centos79_ifort190_sse2_intelmpi-2018_sharelib.usermat.tgz_extractor.sh The license is Purdue University's academic license. I can share our Ansys customer number privately and am happy to continue by email at gngo@purdue.edu.

Dear all, I was wondering whether there is a way to define an isotropic power-law model using the *ICFD_POROUS_MODEL keyword, as is possible in Fluent, for example. The current card only seems to offer the Ergun and Darcy–Forchheimer models. I would appreciate any guidance you could provide on this. Thank you in advance for your help. Best regards, Gred

這是模擬器平衝壓成型的過程，外面還有一個外模具，我的沖壓頭會一直穿過鋁片，前面都已經試過contact了，後面用body interaction還是會穿過去