LS-Dyna Guide

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:

or

To make it load automatically upon login issue:

Running LS-DYNA

Running an interactive serial job

To run the LS-DYNA in the interactive mode, please read interactive first. For example:

Running a parallel job

Firstly, you need a submission script, ls-dyna.sh:

Then you can run the parallel program

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:

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:

Substitute the appropriate executable in the examples above.