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<p>Hi,</p><p>I am trying to analyze shear pin breaking analysis in LS-DYNA Workbench. After 1 hour of running, run progressed to only 1e-6 seconds of 0.25 seconds of total time. Used material has Multilinear Isotropic Hardening and Plastic Strain Failure properties assigned. 56.5k elements are present in the mesh structure. There are no contacts. Force is applied to the surface of the pin. 4 cores are used. Hourglass control no 4 is selected. I can send the archived project file by the method you specify. What is the solution to this problem?</p>
<p>I find a lot of posts about this error using the <span style="text-decoration: underline;">free student</span> version, but here we have the <span style="text-decoration: underline;">academic/research licences</span> and we still experience this error when trying to solve a dummy problem with LS-Dyna: Our sales rep certifies that we are supposed to have access to that solver with our licences. Would you please tell us how to use this solver?</p>
<p>Hi,</p><p>I got an error -> "forrtl: severe (157): program exception - access violation" when running ls-dyna with S-ALE domain, in MPP run mode and using *ALE_Structured_Mesh_volume_filling keyword. Running the same file using SMP is ok. I have to used the keyword *Initial_volume_fraction_geometry to replace *ALE_Structured_Mesh_volume_filling in order to run MPP. I upgraded my solver to V252 but still have this problem. Wonder whether anyone encounters this issue as well. </p>
<p>In a LSDYNA thermal-structural analysis, I am trying to think through if it matters at all if tempearture is in K or in C and if I can set it to Rankine if I wanted? </p><p>To keep unit consistency, is it correct to think that as long as I set every other varaible to have the right unit consistent with the temperature of the problem, it wouldn't matter? <br><br>A prime example is if we have a viscoelastic model with WLF shift function generated from from a reference temperature of 25C in the time-temperature superposition. In that case, must I keep the temperature unit at C or K? or is there a way to use rankine if I wanted? </p><p><span style="font-size: 14pt;">Appreciate the thoughtful feedback. </span></p>
<div>Hello, I am running a cold forging simulation in LS-DYNA using the implicit solver, and I am experiencing a sudden solver termination before the end time.<br>The workpiece is modeled using the EFG (Element-Free Galerkin) formulation (elform 42). At a certain stage of the forming stroke the solver stops abruptly due to negative volume error. I would like advice on which aspects of my model setup should be improved or reconsidered in order to solve the issue. I can post here some of the keywords I use: </div>
<p>Hello, </p><p>I'm trying to modelize high velocity impacts of tungsten balls on tungsten plates, with ranges from 600 to 4000m/s (subhypervelocity). Given the speed, I'd like to use Johnson Cook or Modified Zerilli Armstrong cards, but whenever I use them without the MAT_ADD_EROSION, I have either a non physical behavior (with ELFORM 1), or negative volume issues (ELFORM 2). If I add the MAT_ADD_EROSION card, the ball erodes too much if I use the criteria given in the litterature. Am I on the wrong path ? Are the EFFEPS, MXEPS, MINEPS dependent of the size of the mesh? Do you have any tips ? </p><p>Thanks for you answers! </p>
noe.lacombe@student.isae-supaero.fr
April 20, 2026
<p>I like to ask if it's possible for Ansys to share how exactly does workbench LSDYNA writes out certain keywords and how I can create my own version of writing out input deck. For example, I like to create an object that writes out the *node keyword based on a set of (x,y,z) coordinate based on a coordinate system that I created. This *Node wouldn't be a real node in the GUI but it will show up as a node in LSPP because *NODE exists. </p><p>there are many other examples I like to do myself. </p><p>I am considering writing my own ACT extension to change the behavior of workbench LSDYNA but I would really like to have a place to start, as opposed to starting with nothing. </p><p>Would it be possible to share something?</p>
<p>Hi,</p><p>I am trying to analyze shear pin breaking analysis in LS-DYNA Workbench. After 1 hour of running, run progressed to only 1e-6 seconds of 0.25 seconds of total time. Used material has Multilinear Isotropic Hardening and Plastic Strain Failure properties assigned. 56.5k elements are present in the mesh structure. There are no contacts. Force is applied to the surface of the pin. 4 cores are used. Hourglass control no 4 is selected. I can send the archived project file by the method you specify. What is the solution to this problem?</p>
<p>I find a lot of posts about this error using the <span style="text-decoration: underline;">free student</span> version, but here we have the <span style="text-decoration: underline;">academic/research licences</span> and we still experience this error when trying to solve a dummy problem with LS-Dyna: Our sales rep certifies that we are supposed to have access to that solver with our licences. Would you please tell us how to use this solver?</p>
<p>Hi,</p><p>I got an error -> "forrtl: severe (157): program exception - access violation" when running ls-dyna with S-ALE domain, in MPP run mode and using *ALE_Structured_Mesh_volume_filling keyword. Running the same file using SMP is ok. I have to used the keyword *Initial_volume_fraction_geometry to replace *ALE_Structured_Mesh_volume_filling in order to run MPP. I upgraded my solver to V252 but still have this problem. Wonder whether anyone encounters this issue as well. </p>
<p>In a LSDYNA thermal-structural analysis, I am trying to think through if it matters at all if tempearture is in K or in C and if I can set it to Rankine if I wanted? </p><p>To keep unit consistency, is it correct to think that as long as I set every other varaible to have the right unit consistent with the temperature of the problem, it wouldn't matter? <br><br>A prime example is if we have a viscoelastic model with WLF shift function generated from from a reference temperature of 25C in the time-temperature superposition. In that case, must I keep the temperature unit at C or K? or is there a way to use rankine if I wanted? </p><p><span style="font-size: 14pt;">Appreciate the thoughtful feedback. </span></p>
<div>Hello, I am running a cold forging simulation in LS-DYNA using the implicit solver, and I am experiencing a sudden solver termination before the end time.<br>The workpiece is modeled using the EFG (Element-Free Galerkin) formulation (elform 42). At a certain stage of the forming stroke the solver stops abruptly due to negative volume error. I would like advice on which aspects of my model setup should be improved or reconsidered in order to solve the issue. I can post here some of the keywords I use: </div>
<p>Hello, </p><p>I'm trying to modelize high velocity impacts of tungsten balls on tungsten plates, with ranges from 600 to 4000m/s (subhypervelocity). Given the speed, I'd like to use Johnson Cook or Modified Zerilli Armstrong cards, but whenever I use them without the MAT_ADD_EROSION, I have either a non physical behavior (with ELFORM 1), or negative volume issues (ELFORM 2). If I add the MAT_ADD_EROSION card, the ball erodes too much if I use the criteria given in the litterature. Am I on the wrong path ? Are the EFFEPS, MXEPS, MINEPS dependent of the size of the mesh? Do you have any tips ? </p><p>Thanks for you answers! </p>
noe.lacombe@student.isae-supaero.fr
April 20, 2026
<p>I like to ask if it's possible for Ansys to share how exactly does workbench LSDYNA writes out certain keywords and how I can create my own version of writing out input deck. For example, I like to create an object that writes out the *node keyword based on a set of (x,y,z) coordinate based on a coordinate system that I created. This *Node wouldn't be a real node in the GUI but it will show up as a node in LSPP because *NODE exists. </p><p>there are many other examples I like to do myself. </p><p>I am considering writing my own ACT extension to change the behavior of workbench LSDYNA but I would really like to have a place to start, as opposed to starting with nothing. </p><p>Would it be possible to share something?</p>
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