Welcome to the LS-DYNA Product Space

<p>We have a reference for the column from previous study, and we want to try and simulate it using the parameters they've given us, it consist of Concrete, Reinforcements, and a TNT for blast explosion. However we cannot get the same or predicted result because we didnt really know how to use the software and out time is limited. Can some of the experts help us in understanding how the blasting works in Ansys mechanical. Note that, We know how to make it (Geometry and Engineering data maybe), but we're not sure if its right because the results we get are not the same. Thank you if someone notices this.</p>

<p>In LS-DYNA, when defining multiple *CONSTRAINED_GENERALIZED_WELD_SPOT constraints, if the node sets of two constraints contain the same node, the following error is reported:</p><p></p><p>Does LS-DYNA have another type of constraint or tie that allows two constraints to have node sets sharing the same node?</p>

<p>I recently noticed something I didn't understand with the EM_CONTROL_MAGNET keyword. On page 385 of the keyword manual (https://lsdyna.ansys.com/wp-content/uploads/2025/04/LS-DYNA_Manual_Vol_III_R16.pdf) it mentions there are two inputs, both mcomp to turn on the keyword, and ncycm to set the number of cycles. So it would be written like this:<br>*EM_CONTROL_MAGNET<br>$# mcomp ncycm<br>1 100<br>However, when I use lsprepost to make a keyword file and include the EM_CONTROL_MAGNET keyword, there is no ncycm command, only the mcomp, and it is automatically written as:<br>*EM_CONTROL_MAGNET<br>$# mcomp<br>1</p><p> </p><p>Moreover, with the syntax written by LSPP, the simulation will crash stating "forrtl: severe (164): Program Exception - integer divide by zero" after assembling Fem-Bem matricies, and building P mat, Q mat, and W mat through 100 percent.  This may be a problem with the syntax, or maybe the rebuilding of magnetic vector of a deforming magnet happens too often and there is a threshold somewhere between NCYCM being undefined and 100 that allows the simulation to complete.  If it helps, here is the EM chunk of my .k file<br><br>*EM_PERMANENT_MAGNET<br>$#      id       pid     mtype     north     south        hc<br>         1         1         1         2         1     21033<br>*EM_CONTROL<br>$#   emsol     numls         -   dimtype    nperio         -   ncylfem   ncylbem<br>         1       100                   0         0                   1         1<br>*EM_CONTROL_MAGNET<br>$#   mcomp<br>         1<br>*EM_CONTROL_TIMESTEP<br>$#  tstype    dtcons      lcid    factor     tsmin     tsmas     rlcsf    mecats<br>         3       0.0         0       1.0    1.0E-4      0.25        25         0<br>*EM_CONTROL_COUPLING<br>$#   thcpl     smcpl    thlcid    smlcid   thcplfl   smcplfl<br>         1         2         0         0         0         0<br>*EM_SOLVER_FEMBEM_MONOLITHIC<br>$#   mtype     stype    abstol    reltol     maxit<br>         0         1    1.0E-6    1.0E-4       100<br>*EM_MAT_002<br>$#     mid     mtype     sigma     eosid     murel     eosmu    deatht<br>         1         4       0.0         0       1.1         0    1.0E28<br>*EM_EXTERNAL_FIELD<br>$# fieldid     ftype      fdef     lcidx     lcidy     lcidz<br>         1         1         1         4         2         4</p>

<p>Hi all,</p><p>I am trying to simulate a forming process for PET material. I am trying to use the MAT275 material model on LS DYNA V4.10.8. When I try to simulate the process, the part with MAT275 disappears from the simulation and the simulation immediately shows normal termination. I see no error messages in the .out or messag file. If i use another material model (say MAT124) then the simulation runs correctly. I am using ELFORM 15 shell elements. (Axisymmetric Solid)<br><br>What could be the reason for this? Is it due to bad material parameter definition or is there another issue?</p>

<p>Hello,</p><p>I am running a simulation with LS-DYNA in the workbench. To achieve convergence I need to allow for some penetration. But after the simulation I want to create a Fluid domain from the deformed geometry. There I don't want any penetration between the bodies, as this might lead to small gaps, which are difficult to mesh.</p><p>So my question is: Is the a possibility to define a contact offset between to contacting bodies as there is in Mechanical?</p><p>Thanks in advance</p><p>Moritz</p>

<p></p><p>How do I solve this?</p><p>Details:</p><p>==============</p><p>OS: Almalinux</p><p>Ansys version v252</p><p>Downloaded LSDyna 16.1.1 smp_d     separately</p><p>Used INSTALL attached to installer to install Ansys2025R2</p><p>===================================</p><p>Any idea?</p><p>Kind regards</p><p>Roberto</p>

<p>Dear Ansys LS‑DYNA Support Team,</p><p>I hope you are doing well.<br>We have a customer requirement to run simulations specifically using LS‑DYNA R12.2 (R12.2 180). However, this build does not appear in the Ansys Customer Portal under the standard LS‑DYNA download listings.</p><p>Could you please provide:</p>Download access to LS‑DYNA R12.2 (R12.2.180) for our platform (Linux & Windows); orGuidance on how to obtain this exact build if it is a customer‑specific or non‑public release.<p>If you need any additional information to process this request, please let me know.</p><p>Thank you for your support.</p><p>Kind regards,<br>Gangadhar Rathod.<br>Senior Team Lead Engineer – CAE<br><br></p>

<p>Hello, if possible, I like to confirm some basic understanding of ICFD turbulence models.     To that end, I have a few questions, maybe basic but really appreciate your help:</p><p>1) if I don't use ICFD_control_turbulence or ICFD_Boundary_prescribe_turbulence in a ICFD model in LS-Dyna, does the solver still utilize some default turbulence model or is turbulence (say vortex shedding) completely turned off?  </p><p>2) I have a simple air flow though channel against a ball (spherical wall) problem and if I turn on ICFD_control_turbulence or ICFD_Boundary_Prescribe_turbulence, the solution simply hangs.   I tried different boundary layers thickness/growth in mesh_BL and looked at K-E and K-omega models and tried different inlet velocity conditions, but the solution simply hangs (seems to indicate divergence) and velocity reading is completely wrong. </p><p>In fluent, this would have terminated the job but in Dyna, it seems to be going forever without terminating.    is it possible to help me understand the general logic of what the ICFD solver is checking when we turn on turbulence models?  </p><p>I also appreciate any reading material on this topic.   I've been looking at the basic problems and try to look at the fluent tutorials to try to redo them inside Dyna.   My ultimate goal is to utilize LS-Dyna for strongly coupled FSI problems where even the simplest types of problems become impossible in system coupling between Fluent and Mechanical and that's why Dyna becomes very advantageous. </p><p>Thank you for your help. </p>

<div><p>Dear all,</p><p>I have identified several sub‑keyword classes in<br>...\Lib\site-packages\ansys\dyna\core\keywords\keyword_classes\auto<br>that are incorrectly implemented in the pydyna 0.11.0 release.</p><p>Examples include:</p>define_curve.pydefine_table.pydefine_transformation.pyinitial_strain_solid.pyinitial_stress_solid.pyparameter.pyset_node_general.py...and others.<p>The main issues are related to incorrect data structures, particularly in implementations intended to support multi‑line inputs using a generic Card, whereas the proper data structures should be SeriesCard, TableCard, or TableCardGroup.</p><p>In addition, several other problems have been identified. For example, the INITIAL keyword family is located in the wrong place within the library (inside the boundary directory), while the initial directory is missing entirely.</p><p>I would appreciate hearing from others who may be dealing with similar issues.</p></div>

<p>Goodmorning,</p><p>I'm analysing the impact of a BEAM element with MAT_ELASTIC on the water. </p><p>I need the local pression in different points of the body. I've definied with DATABASE_FSI several different points but importing the .dbfsi results file in post processing I get the same plot for all the points. </p><p></p><p>The odd points I've defined don't plot any results, just a straight line at 0. </p><p>What I'm doing wrong? Is there another keyword to define?</p>