Welcome to the LS-DYNA Product Space

<p data-pm-slice="1 1 []">Hello everyone,</p><p>I am doing impact analysis for a concrete block using Explicit dynamics.</p><p>I used the default concrete Engineering data offered by Workbench, then added Polynomial EOS and J H strength. Both shear modulus and bulk modulus are frozen in the isotropic elasticity properties. After I had finished setup, I tried to run the solution, but I received an error message, "Concrete must have shear modulus defined," and it terminated.</p><p>Could you please help me figure out this problem?</p>

<p>Hello, I am doing a comparison between Ansys Mechanical and LS-Dyna for their modal analysis.    Everything is basically the same except in LS-Dyna, the rotational DOF has 0 participation factors for the 1st 10 modes. </p><p>I first thought that 1) it's because of the scaling of rotscl from implicit_control_eigenvalue but that doesn't check out and 2) it's because it's all solid elements but that it's also solid elements in Ansys Mechanical side. </p><p>Both tool are using block Lanczos mode extraction methods.    Can anyone think of a reason why I get 0 participation factor in rotational DOF in dyna?</p><p></p><p>However, the same problem in Ansys Mechanical returns rotational DOF</p><p></p>

<p>Hello, is it possible to get access to the example files in this ALH course - https://learninghub.ansys.com/learn/courses/1654/simulation-of-adhesive-curing-in-ansys-ls-dyna-software/lessons/11909/media-1</p><p>It's for modelling adhesive curing and there are several demo files at the end that I would really love to look at the input file directly.</p><p>If this is possible, would you please let me know.   You can also send it to my email address at zchen6@gatech.edu.</p><p> </p><p>Thank you</p>

<p>Hello everyone,</p><p>I am modelling impacts on ceramics and have some doubts regarding that. I am using MAT_110 for Alumina (Al2O3). The model consist of cermic and metal (Al) and steel impactor. Both the metals are using JC material model with linear EOS. I am using hourglass 5 (Qm=0.08) and TSSFAC =0.9. I used accuracy card and turned on the hourglass energy in control_energy. I am using Eroding contacts for ceramic and metal against the impactor and Automatic surface to surface between ceramic and metal plate. Some doubts I have are:-</p>Is MAT_ADD_EROSION necessary for ceramic modelling? When i didnt used the erosion card, the penetration is not happening and my projectile is simply passing through the ceramic plate. Or do I have to improvise my contact definations.How to determine the erosion criteria and which parameter to use for the erosion (MXEPS, EFEPS etc.)? Most literature defines it as 0.06 for Alumina. I am defing it for MXEPS but not getting good results. What is the best erosion criteria that should be used for for simulating ceramic impacts?https://www.dynalook.com/conferences/european-conf-2003/implementation-and-validation-of-the-johnson.pdf defines erosion for ceramics as total plastic strain (FS) or if the value is enetered as negative then it represents maximum tensile pressure. Which criteria should be used and when?Is there any standard ceramic-metal armor paper for impact analysis as there may be a chance I am modelling metal incorrectly.<p>Thankyou</p>

<p>hello,</p><p>does someone know how to program user subroutine (umat or ueos ... ) in CESE, i can not find the interface except in icfd, but it seems not the right interface for cese.</p>

<p><p>Dear Ls-dyna community,</p><p>I hope you all are pretty fine. I am reaching out to seek your expertise in ANSYS LS-DYNA, specifically regarding the modeling of crack setups using the MAT_ADD_EROSION material model during the blasting of hard rock.</p><p>I am currently working on a project that involves simulating crack propagation in hard rock under blast loading conditions. I aim to use the MAT_ADD_EROSION model in LS-DYNA to capture material failure and erosion effectively. However, I am facing challenges in setting up the model correctly, particularly in defining the erosion criteria and ensuring accurate crack propagation behavior.</p><p>Could you kindly provide guidance or share best practices for the following:</p><p>·        Properly configuring the MAT_ADD_EROSION parameters for hard rock blasting simulations.</p><p>·        Defining appropriate failure criteria to model crack initiation and propagation.</p><p>·        Any specific meshing techniques or element types recommended for capturing crack behavior accurately.</p><p>·        Common pitfalls to avoid when setting up such simulations in LS-DYNA.</p><p>If you have any example input files, case studies, or references related to similar applications, I would greatly appreciate it if you could share them. Additionally, I’d be happy to discuss my project in more detail or provide specific information about my setup if that would help in tailoring your advice.</p><p dir="ltr">Thank you for your time and consideration. I look forward to your insights and any recommendations you might have.</p><p dir="ltr"> </p><p>Regards, </p><p>Yalew Tebeje</p></p>

<p>I have noticed that LS-DYNA currently provides an integrated LBE+ALE approach, which can more efficiently handle obstacles in air blast simulations. Based on this, I wonder whether the same method could be applied to analyze underwater explosions? In the LBE method, the blast pressure data is derived from the historical CONWEP air blast database. If I have corresponding underwater explosion data, could I use user-defined functions to implement underwater explosion analysis?</p>

<p><p><p>Hello,<br>I'm a student and I want to simulate conrete under the impact of warhead. I need some library and detailed parameters for concete with models as:</p><p>MAT 005</p><p>MAT 193</p><p>MAT 272 </p><p>and MAT 273</p><p>Thank you so much</p></p></p>

<p>As I'm becoming more and more acquainted with LS-DYNA's ALE implementation, I noticed in the Keyword Manual Vol I, CONTROL_ALE description that the smoothing algorithms are not supported by MPP versions. So, if I run a multi-material ALE simulation on my HPC, am I effectivley only doing an Eulerian simulation since the rezoning is not being supported? Can someone help clarify if I am correct in this assumption?</p><p>Peter</p>

<p data-start="64" data-end="69">Hi,</p><p data-start="71" data-end="308">I’ve been trying to run LS-DYNA on a cluster that uses Red Hat 9 with the latest versions of Intel and OpenMPI. However, the only builds I can find are CentOS versions, which were compiled with older versions of both Intel and OpenMPI.</p><p data-start="310" data-end="425">Is it possible to get an LS-DYNA build for Red Hat, preferably compiled with a newer version of Intel or OpenMPI?</p><p data-start="427" data-end="436">Thanks,</p>