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I am using 3D tet remeshing in a FEM application and I can only get a uniform element size in the entire body. I have tried to change "MM" in keyword *CONTROL_REMESHING but it does not matter what value I use I still get a uniform element size. Since I need to use small elements on the surface to get the contacts to work I get a very large number of elements in the body. Is there any way to get the tet element size to grow from the surfaces?

Hi all,   I am running a repeated-impact simulation chain and I cannot get the full-deck restart to work in R14.1.1. I would appreciate any insight into whether thermal-state restore on full restart is expected to work for a coupled S-ALE multi-material model with a phase-change thermal material, and whether the boundary-condition crash described below is a known issue.   SOLVER / ENVIRONMENT - ANSYS 2025 R2 (v252): lsdyna_mpp_dp_msmpi.exe and lsdyna_mpp_dp_impi.exe - Both report: LS-DYNA MPP double precision, Revision R14.1.1-16-gfadfb49b17   (MS MPI V10.0 and Intel MPI builds respectively) - Windows 10/11 x64, 16 MPI processes, double precision - Both the initial run and the restart use the same revision and the same   number of processes, so the d3full version/rank-count requirements are met.   MODEL (initial run, "Impact 01") - 2D axisymmetric S-ALE, coupled structural-thermal:     *SECTION_ALE2D (ALEFORM=11, ELFORM=14)     *ALE_STRUCTURED_MESH + *ALE_STRUCTURED_MESH_CONTROL_POINTS     *ALE_STRUCTURED_MESH_VOLUME_FILLING (ALL / BOXCOR / ELLIPSOID with      velocity vector via VID)     *ALE_MULTI-MATERIAL_GROUP (3 AMMGs) - Materials:     *MAT_JOHNSON_COOK (MAT_015) + *EOS_GRUNEISEN for the HSLA-100 target     *MAT_ELASTIC_PLASTIC_HYDRO (MAT_010) + *EOS_GRUNEISEN for the WC      projectile (2220 m/s)     *MAT_ALE_VACUUM for the surrounding void - Thermal:     *MAT_THERMAL_ISOTROPIC_PHASE_CHANGE for the target (T09)     *MAT_THERMAL_ISOTROPIC for projectile and vacuum     *CONTROL_SOLUTION SOLN=2 (coupled)     *CONTROL_THERMAL_SOLVER SOLVER=12, EQHEAT=1, FWORK=0.9     *CONTROL_THERMAL_TIMESTEP / *CONTROL_THERMAL_NONLINEAR     *INITIAL_TEMPERATURE_SET (NSID=0, 296.15 K) - Boundary conditions via *BOUNDARY_SALE_MESH_FACE: SYM on the axis face   (negx), NONREFL on the posx/negy/posy faces. - *DATABASE_BINARY_D3DUMP writes d3dump01/d3full01 at t = 5.3e-5 s. - *CONTROL_MPP_DECOMPOSITION_DISTRIBUTE_ALE_ELEMENTS is used.   The initial run terminates NORMALLY at t = 5.3e-5 s (4845 cycles) with a physically sound thermal state (final temperature norm ~1.0e5, nonlinear thermal residual norms ~1e4-1e6). d3dump01 and d3full01.0000-0015 are written as expected.   RESTART RUN ("Impact 02") Full-deck restart deck = full model + *STRESS_INITIALIZATION (PIDO=10, PIDN=0, the S-ALE mesh part) + a new *ALE_STRUCTURED_MESH_VOLUME_FILLING (ELLIPSOID, with VID) introducing a second projectile. Executed with:     mpiexec -np 16 lsdyna_mpp_dp_xxxmpi.exe i=restart.k n=d3full01 memory=200m The restart reads the dump correctly (problem time 5.3000e-5, cycle 4845, "material 10 in restart file initializes"), but then fails at the very first cycle in TWO distinct ways:   FAILURE 1 - thermal solver divergence, Error 40359 (SOL+359):     "the minimum time step has been reached and the maximum temperature      change is greater than specified"     solution time 5.3000e-5, node 6234 (inside the previously impacted,     hot region of the target), temperature change 5.2976e+12.   The first thermal solve after restart has an initial residual norm of   7.4432e+22, i.e. 18 orders of magnitude larger than any thermal solve in   the healthy initial run (~1e4-1e6). During the Newton iterations the   trial temperatures drop to ~112 K in material that ended the initial run   hot. The residual is bit-identical whether or not the restart deck   contains *INITIAL_TEMPERATURE_SET, so the initial-temperature card is not   the cause - the thermal state after the restore appears inconsistent/   corrupted regardless of the deck.   FAILURE 2 - access violation in the 2D ALE non-reflecting boundary:   When the NONREFL *BOUNDARY_SALE_MESH_FACE card is active, the run instead   crashes at the first mechanical cycle with     forrtl: severe (157): Program Exception - access violation     NRBCALE2D (dyn60.F, line 36922) <- APPLY_LOADS <- FEM3D <- SOLTN   With the NONREFL card commented out, this crash disappears (the run then   reaches Failure 1 instead). The identical NONREFL setup runs without any   problem in the initial (non-restart) run.   QUESTIONS 1. On a full-deck restart with *STRESS_INITIALIZATION + n=d3full01, is the    nodal temperature field (and phase-change history) of a coupled    structural/thermal S-ALE model supposed to be restored from the dump?    Any known limitations for MAT_THERMAL_ISOTROPIC_PHASE_CHANGE on restart? 2. Is the NRBCALE2D access violation on the restart path a known issue for    2D S-ALE non-reflecting boundaries? (I noticed the R14.1.0 release note    about an incorrect shear modulus in 2D S-ALE non-reflecting boundary    elements, and the R14.0.0 fix to *BOUNDARY_NON_REFLECTING_2D for    discontinuous boundary lines.) 3. Is there a documented workaround other than abandoning the restart and    running both impacts as one continuous simulation (which is my current    fallback)?   For context: under R16.1.1 the same model family crashes at cycle 0 with an access violation inside *MAT_THERMAL_ISOTROPIC_PHASE_CHANGE (already reported separately), which is why this chain was migrated to R14.1.1.   I can provide the keyword decks, d3hsp/mes files, and (if useful) the d3full01 family as a reproducer.   Thanks in advance, Amrith  

I am attempting to create a 27-node solid 3D user-defined element with the LS-Dyna object code. However, it appears to me that the object code is hard coded in many, many places for 8-node solid elements. For example in the dyn21usld.f file and then in the usrsld() subroutine, the main subroutine the calls the user-defined element subroutine, declares the bmtrx variable as: common/bel7loc/bmtrx(nlq,3,3,8*(3+NXDOFUE)) where (based on my interpretation): nlq - number of elements in current block 3,3 - matrix of shape function derivatives 8*(3+NXDOFUE) - number of nodes,8, times the number of degrees of freedom per node This matrix is hard coded in many places throughout the dyn21usld.f file. Also, this is just one example of the hard coded nature of an 8-noded element there are also other variables such as the bvec array, as well as, do-loops that appear to be hard-coded for 8-nodes.  Q1: Can user-defined elements be developed with more than 8-nodes per element?  Q2: Does that require tracing through all the places where an 8-node element is assumed?  Q3: Is there an easier way to develop a user-defined element with more than 8-nodes rather than finding all the places where it is hard-coded? Q4: How will the rest of the program know how many nodes are being used for the element?  Q5: Am I correctly interpreting that at least some of the variables and do-loops are hard-coded for 8-node solid elements?     

Hello, I want to ask if there's any instruction on how I can modify the default behavior of workbench LSDYNA in terms of how it writes out input files. For example, if I want to use a material model by inserting a lsdyna commnand in the geometry section, it doesn't allow me to put the load curve in that same command file, I have to insert it under lsdyna analysis setting.  I like to modify the input write-out logic such that load curve can be inserted in the command under geometry. There are many other examples, is it possible?

I am running an implicit analysis on a foam-filled square tube. I am using a single curve for both the loading and unloading. The solver crashes during the unloading phase. Could you please advise on which inputs are incorrect or causing conflict? squaretubefoam.key

Additional controlled test completed: a 2× S‑ALE mesh refinement changed the maximum total-energy loss only from 1.58755% to 1.59180%. Mass conservation, geometry, stable timestep, GLSTAT component closure and material-account closure all pass. The loss is primarily associated with the EMULSION material. Could anyone clarify two R16.1 output semantics questions? Is Ekinlos an additive energy term that should be included in the global conservation balance? Which supported database/output gives per-cell, per-material internal energy, kinetic energy and burn fraction for axisymmetric S‑ALE with *MAT_HIGH_EXPLOSIVE_BURN/JWL? These definitions are needed before further numerical changes can be interpreted.

Hi everyone, I am setting up an ICFD simulation of gas flow through a porous domain in LS-DYNA. The model currently consists of the  fluid domain and the porous-medium region; I am not yet including structural deformation. During initialization, the simulation terminates with the following error:   *** Error 120003 (ICFD+3) ICFD::ERROR: Invalid BC on SIZE or INTERF surf. PID 1     The simulation does not proceed beyond initialization. I am using an ICFD volume part for the porous medium and have defined the corresponding ICFD material and porous-medium model. I suspect that the issue is related to the boundary condition assigned to the surface with PID 1, but I am unsure what constitutes an invalid BC for a SIZE or INTERF surface in this setup. Could someone please clarify: What does "Invalid BC on SIZE or INTERF surf. PID 1" specifically mean? What boundary conditions are permitted on SIZE and INTERF surfaces? How should the surfaces of a porous ICFD volume be defined when modelling hydrogen flow into/through porous soil? Is there a particular ICFD keyword or surface definition that I should check? Thank you in advance.

Hello all! I'm currently extracting several variables from my model where several bodies contact one another with a near-frictionless penalty-based contact (*CONTACT_AUTOMATIC_SINGLE_SURFACE). I'm trying to compare contact variables to an experimental reference where they report peak pressure, mean pressure, and contact area gathered using Tekscan pressure films. I have some questions that I hope someone else has experience with. If two different parts are in contact, should both parts have the same contact pressure, force, and area readings? I have a force transducer on each of the two contacting parts, and I found that the forces from RCFORC agree pretty much exactly, but the results for pressure and contact area were close (~5 to 20% difference) and not exactly the same. Is this related to the mesh or element density, or could it point to something wrong in my contact setup? If it is just discretization, is there a recommended convention for which side to report or to average both sides? I noticed that I have access to several "pressure" variables in LS-PrePost, so I'm wondering what each variable represents and which could be better suited to my purpose:a) "Pressure" from d3plot, which I guess could be hydrostatic pressureb) "Interface Pressure" from intfor, obtained using a transducerc) "Peak Pressure" from intfor, after setting NPRESU to 3 on *DATABASE_EXTENT_INTFOR I compared these three variables across several simulations and the values were close, but not exactly the same. Is any of these options better to compare against a pressure film? Also, what's the difference between peak pressure and just taking the maximum value of interface pressure at a given state?3. Related to the above, I also need contact area for the same comparison. Would anyone know how LS-PrePost computes the "Contact Area" quantity? Is there a threshold being used to sum elements or does it add all elements with nonzero values?Thanks in advance for any guidance!Best,  Andres  

Hello, I am currently using the Ansys LS-DYNA Student version for my academic research. Until a few days ago, LS-DYNA displayed the following warning when I started an analysis: Student license active, 1 days remaining. The license has now expired, and LS-DYNA terminates with the following messages: [license/error] *** ANSYS LICENSE MANAGER ERROR ***[license/error] Request name dyna does not exist in the licensing pool.Student license expired 2 days ago.*** Error 70022 (OTH+22)Error termination Therefore, I am currently unable to run LS-DYNA analyses. I checked the official Ansys Student download pages to renew the license. However, I could not find a newer LS-DYNA Student version with an updated built-in license. I understand that the LS-DYNA Student license is built into the Student version and that simply replacing a license file is no longer the recommended renewal procedure. Could you please advise me on the following? Is there a newer version of LS-DYNA Student with a valid license that I can download? If not, how can I renew or update the LS-DYNA Student license? Is there another recommended procedure for continuing to use LS-DYNA Student until the next version is released? I have attached a screenshot of the Error 70022 message for reference. Thank you for your assistance.

Hi! I'm having some trouble downloading LS-PrePost.Every time I try to connect to the FTP server, I get the following error: Access Denied You don't have permission to access "http://ftp.lstc.com/anonymous/outgoing/lsprepost/" on this server.