Welcome to the LS-DYNA Product Space

<p>Hi <br>According to my research, GPU acceleration is not available for the explicit LS-DYNA solver. However, I came across the following article on the NVIDIA website:<br>https://developer.nvidia.com/blog/advancing-ansys-workloads-with-nvidia-grace-and-nvidia-grace-hopper/ </p><p>The car crashing cannot be implicit so could you please clarify whether GPU acceleration is available for the explicit solver or not?</p>

<p>Hello,</p><p>Is it possible to simulate the FSI using CESE fluid solver with a structural component defined using SPH. If yes, which keywords are required to define coupling?</p><p>Regards,<br>Atish </p>

<p>Hi,</p><p>I downloaded input files for battery modelling from https://lsdyna.ansys.com/battery/#download. Some of them cannot be run due to different problems. </p><p>For the input file of Basic_intshort, it shows *** Error 10246 (KEY+246)<br>     line contains improperly formatted data<br>      *** Error reading *EM_MAT card.<br>          At line# 89 of file<br> --------------------------------------------------------------------------<br>          4         1<br> --------------------------------------------------------------------------<br> <br> *** Error 10450 (KEY+450)<br>     in keyword command:<br>         5         2    3.70e7<br>          At line# 90 of file<br>For the case of  Basic_socshift,   it shows</p><p> *** Error 10246 (KEY+246)<br>     line contains improperly formatted data<br>      *** Error reading *EM_MAT card.<br>          At line# 67 of file<br><br> --------------------------------------------------------------------------<br>          4         1<br> --------------------------------------------------------------------------<br> <br> *** Error 10450 (KEY+450)<br>     in keyword command:<br>         5         2    3.70e7<br>          At line# 68 of file<br> For the case of Meshless, it shows</p><p> *** Error 10307 (KEY+307)<br>     CHECKING MATERIAL INPUT Part ID= 1<br>     PART ID 1 has TMID= 0 which does not exist.<br>     This is PART 22 in the order of input.<br>     Coupled structural thermal analysis needs to have a thermal material ID defined.</p><p>There are different errors with other cases. I am using R16 solver, I wonder if these input files are old or other reasons. Thank you!</p>

<p>Hello everyone.<br>Please help me configure CONTROL_CONTACT so that Contact doesn't return calculation errors:</p><p></p><p>Thank you.</p>

<p><p>Hello everyone, I am modeling a reinforced concrete column under axial load applied as a rigid body load. I modeled the concrete using solid elements elform of 3 and hourglass type 3, for rebars I am using beam element. Concrete material is MAT072R3 and steel is MAT024. For bond between concrete and steel first I used Lagrange in solid but it was affecting the stress distribution in concrete then I switched to beam in solid which seems no issues in concrete stresses. However, I am not able to see the stress in rebar in either cases whether using Lagrange in solid or beam in solid. It seems the stress or axial force is not getting transferred to rebar because when running the simulation there is no movement in rebar. I did activate the extent binary keword by putting the value of BEAMIP to 1. I would appreciate your help to solve this issue I am facing. Please see attached photos for clarity.</p><p>  </p><p></p>

<p></p><p>I'm analysing the impact of a MAT_ELASTIC shell with S-ALE formulation but is not realistic.</p><p>A few steps after  the contact with water, the ALE element drops down before touching the shell. </p><p>I've tryed many different setups and keyword but the issue doesn't expire</p><p> </p><p> </p>

<p>Hello everyone, I'm calculating a rubber cylinder in the LS-DYNA workbench. Steel vanes are installed inside the cylinder so that when the rubber inflates, the vanes prevent it from deforming too much.<br>The contact between the rubber and the vanes constantly causes a negative volume error and eroded node errors. Please help me set up this contact. I've tried everything, including the built-in contact bonded in the workbench, setting the offset, changing the contact type to normal Lagrange, etc. I've also tried using the snippet insert command contact TIDE with different settings. I've refined the grid to 20 million cells.<br>Nothing helps. Please help me set up the contact; if I turn it off, everything works fine.<br>Thank you.</p><p></p><p></p>

<p>Hello, I want to inquire about if LSDyna ICFD solvers implement wall functions and where I can find some information about this?  </p>

<p>Hi Everyone</p><p>I created a dome composed of many beams as shown in the figure 1 and 2, and made a cylinder imapct it. I applied *CONTACT_AUTOMATIC_BEAMS_TO_SURFACE_ID between the cylinder and each beam. As for beams, there is a little difference in height between 2 beams. I didn't add any contacts. I added *CONSTRAINED_GENERALIZED_WELD_SPOT or *CONSTRAINED_SPOTWELD between the nodes of 2 beams closest to the intersection. After I ran the simulation, the cylinder went through the dome rather than impacting it, as shown in figure 3. The beams appeared to have a little oscillation. It seems that there is still some interaction force between the beam and the cylinder. But the cylinder just directly went through the beams. Does anybody know the reason and how to fix it? </p><p>I attached my .k file : https://tuprd-my.sharepoint.com/:u:/g/personal/tut06916_temple_edu/IQAtEDBPZhKLRYw4Kr0EEa_AAeYXal-n6FkEF1ROSpG_67k?e=86nLOW</p><p></p><p></p><p></p>

<div class="text-neutral-content"><div class="mb-sm mb-xs px-md xs:px-0 overflow-hidden" data-post-click-location="text-body"><div id="t3_1rr5r9z-post-rtjson-content" class="md text-14-scalable pb-2xs [--emote-size:20px]" dir="auto"><p>Hi,</p><p>I'm modeling hypervelocity impact (2.22 km/s tungsten carbide sphere on HSLA-100 steel) with coupled thermal-structural analysis using S-ALE (Structured ALE) mesh.</p><p>Initial Attempt & Issue:</p><p>I first tried the implicit thermal solver using:</p><p>- *CONTROL_SOLUTION (Thermal-Structural Analysis)</p><p>- *CONTROL_THERMAL_NONLINEAR</p><p>- *CONTROL_THERMAL_SOLVER</p><p>- *CONTROL_THERMAL_TIMESTEP</p><p>However, I observed physically unrealistic temperature rates (dT/dt on the order of billions of °K), which is physically impossible. I switched to the Explicit Thermal Solver (*CONTROL_EXPLICIT_THERMAL_* cards) as an alternative, but encountered a fatal initialization error.</p><p>Current Error:</p><p></p><p>forrtl: severe (164): Program Exception - integer divide by zero</p><p>Image PC Routine Line Source</p><p>lsdyna_mpp_dp_imp 00007FF731E6B4CC XPLCTH_INIT 1148 dyn20x.F</p><p>...</p><p></p><p>The crash occurs during initialization (XPLCTH_INIT), suggesting a division by zero in the thermal data setup.</p><p>Specific Questions:</p><p>Explicit Thermal Setup with S-ALE:</p><p>For cards like *DATABASE_ALE, *CONTROL_EXPLICIT_THERMAL_INITIAL, and *CONTROL_EXPLICIT_THERMAL_OUTPUT, the manual states SETID can be left blank for "all parts," but LS-PrePost/LS-DYNA requires an integer. Since S-ALE mesh elements are generated internally at runtime (not predefined in *ELEMENT_SHELL), I cannot reference them via traditional *SET_SHELL_LIST.</p><p>- How do I properly define SETID for S-ALE domains in these cards? Should I use *SET_MULTI_MATERIAL_GROUP instead?</p><p>Phase Change Modeling:</p><p>My material definition includes *MAT_THERMAL_ISOTROPIC_PHASE_CHANGE for the steel target (solid-to-liquid). Does the Explicit Thermal Solver support phase change energy (latent heat), or is this capability restricted to the implicit thermal solver? If supported, are there specific considerations for S-ALE multi-material groups?</p><p>Divide-by-Zero Cause:</p><p>The error trace points to XPLCTH_INIT (dyn20x.F:1148). This typically indicates zero thermal mass (density × specific heat) in a thermal part definition. Given that my vacuum/void material (*MAT_ALE_VACUUM) has near-zero thermal properties, could this be triggering the crash? Should vacuum regions be excluded from the thermal solver via *SET_PART_LIST, or is there a minimum non-zero thermal density requirement?</p><p>Model Context:</p><p>- 2D Axisymmetric S-ALE mesh (fine resolution)</p><p>- 3 ALE Multi-Material Groups: HSLA-100 Steel, Tungsten Carbide, Vacuum</p><p>- Thermal properties defined via *MAT_THERMAL_ISOTROPIC and *MAT_THERMAL_ISOTROPIC_PHASE_CHANGE</p><p>- Using MPP R14.1.1 on Windows</p><p>Keyword file attached for reference:</p><p><a class="relative pointer-events-auto a cursor-pointer underline" href="https://buffalo.box.com/s/y7rz3bqg4xsvuir6z94b50mcg2g3jp1s" target="_blank" rel="noopener">https://buffalo.box.com/s/y7rz3bqg4xsvuir6z94b50mcg2g3jp1s</p><p>Any guidance on proper explicit thermal initialization with S-ALE and phase change setup would be greatly appreciated.</p><p>Thanks,</p><p>Amrith</p></div></div></div><div> </div>