--- title: "LS-Dyna Guide" canonical: "https://kb.uconn.edu/space/SH/26033653105/LS-Dyna%20Guide" format: markdown --- ### LS-DYNA LS-DYNA is an advanced general-purpose multiphysics simulation software package developed by the Livermore Software Technology Corporation (LSTC). While the package continues to contain more and more possibilities for the calculation of many complex, real world problems, its origins and core-competency lie in highly nonlinear transient dynamic finite element analysis (FEA) using explicit time integration. LS-DYNA is being used by the automobile, aerospace, construction, military, manufacturing, and bioengineering industries. LS-DYNA smd version is used on single node multicore and LS-DYNA mpp version is used on multiple nodes. ### ANSYS LS-DYNA is now part of the ANSYS suite of products, and is not installed as a separate product on HPC. To use LD-DYNA first load he ANSYS module. ### Loading the Module To load the newest version, issue the command: ``` module load ansys ``` or ``` module load ansys/R2023R2 ``` To make it load automatically upon login issue: ``` module initadd ansys ``` ### Running LS-DYNA #### Running an interactive serial job To run the LS-DYNA in the interactive mode, please read [interactive](https://kb.uconn.edu/space/SH/26032963685/SLURM+Guide) first. For example: ``` [hpc-user@login4 ~]$ fisbatch --ntasks=12 --nodes=1 --partition=general FISBATCH -- the maximum time for the interactive screen is limited to 6 hours. You can add QoS to overwrite it. FISBATCH -- waiting for JOBID 52319 to start on cluster=cluster and partition=Westmere ! FISBATCH -- Connecting to head node (cn04) [hpc-user@cn423 ~]$module load ansys/R2023R2 [hpc-user@cn423 ~]$lsdyna_dp.e *************************************************************** * ANSYS 2023 R2 LEGAL NOTICES * *************************************************************** * * * Copyright 1971-2023 ANSYS, Inc. 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The software products and documentation may be * * used, disclosed, transferred, or copied only in accordance * * with the terms and conditions of that software license * * agreement. * * * * ANSYS, Inc. is a UL registered * * ISO 9001:2015 company. * * * *************************************************************** * * * This product is subject to U.S. laws governing export and * * re-export. * * * * For U.S. Government users, except as specifically granted * * by the ANSYS, Inc. software license agreement, the use, * * duplication, or disclosure by the United States Government * * is subject to restrictions stated in the ANSYS, Inc. * * software license agreement and FAR 12.212 (for non-DOD * * licenses). * * * *************************************************************** Date: 11/13/2023 Time: 12:56:01 ___________________________________________________ | | | LS-DYNA, A Program for Nonlinear Dynamic | | Analysis of Structures in Three Dimensions | | Date : 11/15/2022 Time: 13:48:14 | | Version : smp d R13 | | Revision: R13.1.1-13-g5480eca294 | | | | Features enabled in this version: | | Shared Memory Parallel | | CESE CHEMISTRY EM ICFD STOCHASTIC_PARTICLES | | FFTW (multi-dimensional FFTW Library) | | ARPACK (nonsymmetric eigensolver library) | | ANSYSLIC enabled | | | | Licensed to: | | | | Platform : Xeon64 System | | OS Level : Linux 4.4.49 uum | | Compiler : Intel Fortran Compiler 19.0 SSE2 | | Hostname : login4 | | Precision : Double precision (I8R8) | | | | Unauthorized use infringes Ansys Inc. copyrights | |___________________________________________________| please define input file names or change defaults : >i= [hpc-user@cn423 ~]$ exit Connection to cn423 closed. FISBATCH -- exiting job [hpc-user@cn423 ~]$ ``` #### Running a parallel job Firstly, you need a submission script, ls-dyna.sh: ``` #!/bin/bash #SBATCH -c 12 # number of the cpus assigns to the job #SBATCH -p general # specify a partition export LSTC_LICENSE="ansys" lsdyna_dp.e i= ``` Then you can run the parallel program ``` sbatch ls-dyna.sh ``` #### Memory allocation Depending on the ls-dyna executable that is used from above, memory allocation can change. The double precision executables have an option to specify the memory2 parameter along with memory1 to allocate memory to the ls-dyna job. MEMORY_2 depends on the number of processors, the more number of processors, the smaller the decomposed model, and consequently, smaller the memory required. MEMORY_2 (only for MPP) depends on the number of processors. A good number would be to start with 20-40% of the total memory available on the nodes after which LS-DYNA will then dynamically allocate more memory if required. MEMORY_2 is used for the remaining processes not allocated to the decomposition model. The memory2 option is used by all the processors (including the master processor) to solve the various decomposed problems that are performed in ls-dyna. This description indicates that it will use allocate the memory that is declared in the command line option to all the assigned nodes for the job. It is recommended to allocate memory to the decomposition using the memory1 parameter (this value will change depending on the model) and the job will allocate the needed memory it needs for memory2 later on after the decomposition completes. command syntax would be: ``` mpiexec lsdyna_dp.e i=inputfile memory1=24000m ``` 24000m is equivalent to 24000 mega words or 192GB (24,000 Megabytes (24 GB) * 8 Bytes) Feel free to change the memory1 value to the needed value to complete the decomposition model. #### Single vs. Double Precision LS-DYNA has four separate executables that are designed for the following use cases: | | | | --- | --- | | lsdyna_dp.e | Double-precision | | lsdyna_dp_mpp.e | Double-precision, Massively Parallel | | lsdyna_sp.e | Single-precision | | lsdyna_sp_mpp.e | Single-precision, Massively Parallel | Substitute the appropriate executable in the examples above.