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I have developed a subroutine for an orthotropic material and implemented in LSDYNA. I want to delete elements once all integration points (in-plane and through thickness) have failed (not only one). Just wondering how that can be done? Thanks

Hello All, After a reboot of our license server, we are required to reconfigure the licensing for LS-Dyna. Is this expected behavior? Do you have any workarounds? Any help is much appreciated. Thanks

Hi everyone, I'm having trouble using near-field dynamics and restart in LS-DYNA, is there any keyword to save the results of the first near-field dynamics calculation?

How can i solve this error?

Hi everyone. I want to share nodes with each other. Also, I want it to be a bonded condition, not a friction condition. Both are solid elements. What contact conditions can I use? Please help me.

Hello,A problem occurred when we needed to simulate an electromagnetism problem with FEM-BEM; we needed to simulate magnetic pulse welding. The magnetic pulse welding process is shown in Figure 1。 We want to simulate the deformation process of the flyer plate using Dyna simulation.Figure 1I could get the simulation results perfectly when my flyplate was just aluminium as shown in figure 2. However, when I add aluminum foil to the aluminum plate, as shown in Figure 3, the dyna does not give me any results or will not converge.Figure 3Why is Dyna not able to calculate the results? We desperately need to simulate the deformation of aluminum plates and foils; Using R15 MPP double precision.Please help me.Regards  

I am doing a simulation where I use eroding contact definitions. When I run a job it makes it through initialization, but then after some time terminates the job with Press any key to continue...I cannot determine the source of this issue, I am running on SMP double 12.1, but this issue persisted with SMP double 14.x. Has anyone experienced this issue and know what the fix is? 

Hello, can you tell me which parameter in the tiebreak contact in LSDYNA mainly controls the strength of the bond?

Hello community,this is my first time trying to set up a Ls-Dyna Restart simulation. I tried different methods but each seem to come with their own difficulties.I would greatly appreciate solution approaches.First Option: Export dynain file and import via external model into new Ls-Dyna systemAdvantages: Import deformed mesh and initial stresses.Issues: Weird artifacts - perhaps due to initial penetration of contacts.I tried to check for and handle this with a keyword snippet:*CONTROL_CONTACT$#  slsfac    rwpnal   islchk   shlthk   penopt   thkchg   orien    enmass      0.0       0.0       0        1        1        0        2        0$#  usrstr      0$#  sfric      0.0$#  ignore    frceng   skiprwg  outseg   spotstp  spotdel  spothin      0         1        0        1        0        1        0.5*ENDSecond Option: Ls-Dyna Restart systems in WorkbenchAdvantages: Easy to understandDisadvantages: Limited features-especially full restartI started with a small restart to delete parts that are not needed for the restart(the full restart does not seem to support that). I tried keyword snippets to delete those parts in the full restart but even though no error appeard the parts continued to exist.With the small restart before the full restart, I can delete those parts. However the full restart only works when connected to the original Ls-Dyna system and not when connected to the small restart.First Option: Export dynain file and import via external model into static structuralAdvantages: No weird artifactsIssues: The initial stress state is imported but based on the stresses at time 0, the stresses are not applied.best regards,Marco

Hello everyone!I am trying to model the penteration of a dropped steel cone for a layer of sand rested on a concrete slab using Explicit dynamics. The thickness of both the concrete and sand layers is 0.5 meters. I simulated the cone material and concrete material with Structural Steel NL and Concrete NL but I cannot find the non linear model of sand.Additionally, I am uncertain about the ideal size for the prism of sand and concrete, considering that the cone's diameter can reach up to 60 cm. I also need to determine the optimal end time for this problem.Regards

Hello.I want to make a fringe plot with some given data calculated by another source.In order to apply data into LSPrePost, I want to utilize User Element Value at User tab in Fringe Component.Is there any information about the file FORMAT?Thank you.😀

Hey, i need help with turning operation in explicit dynamics and analyse temperature, We designed our tool where we kept the insert structured. Then, we designed the workpiece as a tube with a thickness of 2.5mm. After that, we did our assembly in SolidWorks. We tried explicit dynamics on ANSYS. But in the end, either the tool does not move, or if it does move, the workpiece gets deformed and chips are not removed. Or the tool goes inside the workpiece without doing any machining. Our main purpose is to note down temperature while the chips are being removed. Feed is to be kept constant of 0.1 mm/rev. And 9 variation of speed starting from 100m/min to 900m/min. tungsten base uncoated flat cemented carbide (material pf insert) and AISI/SAE 4140 high tensile alloy steel (material of workpiece). We set the end time of 0.005 sec and number of cycles we used were 1000 cycles. What end time and preferred number of cycles should we use to get 5mm length of cut, insert is not touching the wp and is almost at a minor distance of 1.13mm. I need urgent help. @peteroznewman

I created a model on LS-Prepost, but the model is not displayed.How should I do?Thank you.

Hi everyone. I want to apply a pressure of 10kPa. What keywords should I use? Please help me.

Hi all,We are setting up the ANSYS structural package on one of our computers here and have followed the steps taken to have it set up before. For some reason this time we keep getting error messages regarding the MPI that can be seen below with the screenshots. The full structural package was installed including the MPI. Does anyone know what may be causing this?Thank you, Grant.

Hi all.I've done a fatigue test and have questions.I model a tungsten carbide drill tip that drills an SPG die, with a ring of solid body around the die for securing. The material of the die and ring is Mora-Columba concrete.  The units I use are: GPa, mm, ms.The rotation of the drill is set at a speed of rad/ms. I did a short calculation (2 hours), the drill rotated about 30 degrees during this time (the total solution to the problem was 60 hours).I checked the d3plot file. Adequate stress: Next, I decided to do a fatigue analysis to check what it would look like.I got inadequate results:   1. The cumulative damage ratio is too high.2. Expected Fatigue Life - too small, the elements will only last 235 seconds under load? But they drill with such a drill for many hours or even the whole day. Tungsten carbide is a very durable material with high density.3. Expected fatigue cycles are generally empty. Why?Help me understand the results, what could I have done wrong?I also apply some basic fatigue tinctures: SN curve for drill: I also got this warning when I increased the starting point in the SN curve, I got the following results: The damage has become less, it is gone, but the lifespan is still short. PS. To reduce calculation time, I increased the density of the die, ring and drill by 4e10, can this make a difference? Please, help. Thank you.

Hello, I'm trying to set up a simple 2D axisymmetric simulation using the compressible CESE Chemistry (inviscid). I defined an H2-O2 reaction mechanism with 8 reactions and gave the thermodynamic input file.Background:The simulation domain is a rectangle with solid walls and an ignition zone with high pressure and temperature. When I use a 2D planar simulation (igeom=2), a shock wave develops and propagates in the H2-O2 mixture. The temperature, pressure and speed of the shock wave closely match the theoretical CJ values for hydrogen detonation, so I assume the simulation is correct (see the image below). Problem: However, when I switch to the 2D Axissymetric simulation the simulation doesn't converge and weird/non-physical values show up in the results. Instead of a uniform propagation of the shock wave, I get random spots with non-sense values (even away from the ignition point), as shown below. The only difference to the 2D planar simulation is that I define the *CESE_BOUNDARY_AXISYMMETRIC in the y-axis and change the *CESE_CONTROL_SOLVER card to perform a 2D axisymetric simulation (igeom=101). The error message is: *** Error 150209 (CHEM+209)     Chemistry EOS nonlinear temperature solver failed to converge.     Error code = 50 Last iterate temperature = -0.21165E+04I tried to simplify the problem by reducing the reaction mechanism and removing the ignition but the problem persists. Additionally, I reduced the mesh size and the time step and still doesn't converge. However, if I run the CESE axisymmetric simulation without the chemistry cards the results are okay.Has anyone faced similar problems or has any idea on how to approach these issues?? I need to set up the axisymmetric case since my next step is to run a simulation of a cylinder with bigger dimensions. 

Hello, I am trying to set up an FSI simulation. I want to manually define the coupling pressure using a load curve ID. For the pressure as a function of penetration depth, I want to scale the coupling pressure values depending on the Z coordinate of a node on my lagrangian structure. To get the Z coordinate of the node, I can use the *DEFINE_CURVE_FUNCTION keyword.How do I use this obtained z coordinate to define a scale factor for the coupling pressure curve?The coupling pressure curve must have the penetration as the absissca and the scaled(time varying and depends on z coordinate) value of the coupling pressure as the ordinate. 

Problem description: There is confining pressure around the rock, the explosive explodes in the blast hole, and the rock in the red area is broken, causing the confining pressure to be released, unloading occurs, and the remaining rock stress is redistributed.How to simulate the stress redistribution of remaining rock caused by rock crushing in Dyna?

Hello everyone, I need some assistance with LS-Dyna. I am currently working on a beam model and I am interested in understanding how the strain of each element relates to the overall displacement. I can already generate curves for stress over time using history - elements. I extract the displacement data through an ASCII-nodout. Normally, I would create an XY plot and cross-reference these values, but this is not possible with stress data. My goal is to create a histogram in python that shows x% of the values are within a range of x-x at a displacement of x mm. Is there perhaps a better method to achieve this? Thank you in advance for your help.

Hello everyone. How can I import mesh to LS-Prepost?I`m trying open .k file in LS-Prepost which was imported from Workbench LS-dyna. In this case all information from Workbench transfer to LS-prepost but I want only mesh.Is this possible open .k file only with FEM part or may be I should use other software for mesh and after that open in LS-Prepost?

Hi all. I assigned a SPC to the body along the edge, but it still moves!Why? Thank you.

Hello, I am looking for tips and advice for the best way to set up my simulation.Background: I want to investigate the effect of far field soil liquefaction on soil-structure-interaction (SSI) results of a deeply embedded cylindrical structure under earthquake loading. Goal is to to conduct a parametric study, representing the structure by linear elastic elements, surrounded by non-liquefiable backfill soil (modelled nonlinear, red in screenshot attached), and liquefiable soil (modelled nonlinear, green in screenshot attached) in the far field. I would then change the extent and properties of the non-liquefiable soil until the impacts on the SSI results are negligible. Since I am only interested in the relative difference in results of the different scenarios, I was thinking a 2D analysis would be appropriate.At this time my two main questions / concerns are:1) To model soil liquefaction I want to follow the approach per paper by Richard Sturt 'Modelling liquefaction of soils with LS-DYNA using a SANISAND-based material model'. Now per my research so far the SANISAND material model is meant for solid elements only. So is the MAT_HYSTERETIC, which I was planning on using for the non-liqueqfiable soil. Could I use these material models in a 2D analysis ? Apparently they do work for plane strain and axisymmetric shell formulations (and thick shell formulations for MAT_HYSTERETIC)...2) When solving a very simple 2D analysis in LS Dyna, I received the following warning message: "A 2D-Model is a beta feature for an Explicit LS-Dyna analysis." All papers / examples I found on SSI using LS Dyna are 3D models. Now I am wondering if a 2D analysis is a good choice in general ? Or should I rather opt for a full 3D simulation ? My main driver for a 2D analysis was simplifying the modelling and saving computing resources. But if I run into issues and can't find any documentation or resources, I have gained nothing. I want to note I am very new to Ls Dyna, and Ansys in general.I am using Ansys workbench 2024R1 (not the student version). Grateful for any advice I can get! Thank you.Joerg

I am recreating the floating ship model found in https://ftp.lstc.com/anonymous/outgoing/hao/sale/ by replacing all the keywords with the ones for Structured FSI. (Structured mesh volume filling, Structured_FSI, Structured multi-material group) etc. I am sucessfully able to replicate this example and also include ambient elements of AETYPE =4 to simulate an infinite fluid region.But I do not understand the nature of Fluid structure interaction and the behaviour of the lagrangian part. The example has the lagrangian container defined with a shell element of thickness 0.2 m and steel as the material. But the deformations observed from the simuations are very unrealistic. I have also attempted changing the material properties and shell element thickness, but they seem to show no difference in the results.Similarly i have also tried to change the structure to a rigid by chaning the material keyword. But again the entire lagrangian structure remains fixed in space (similar scenario happens also with the example file).Could someone please guide me to a proper 3D setup of hydrostatic equillibrium for a floating body.Thanks & RegardsAbhemanyu

Hello all, In Workbench LS-Dyna I'm trying to set up an S-ALE problem. I create the material using "LSDYNA External Model" tool with *MAT_JOHNSON_COOK and *EOS_GRUNEISEN models. After running I get the error:  *** Error 41319 (SOL+1319)     The # 1 ale multi-material which is of material     type 15 has element erosion set. Please define an     vacuum material and make it one of the ale multi-materials     so the failed material could be switched to vacuum. So, MAT_JOHNSON_COOK model requires dummy vacuum material in *ALE_MULTI-MATERIAL_GROUP to replace it during material failure. The issue is that *ALE_MULTI-MATERIAL_GROUP card is created automatically and filled with materials from ALE bodies material assignments. Each body has only one material assignment. Furthermore, there is no *MAT_VACUUM model in "LSDYNA External Model" tool. Is it possible to overcome this issue? -- Regards, Dmytro Fedin