LS-OPT 4.0 is now released.

The LS-OPT Version 4.0 beta release is now available at: LS-OPT 4.0 The Presentations folder has an overview and outlook of LS-OPT. The main feature is the next generation post-processor (Viewer). Note that LS-OPT/Topology will be available later in 2009 as a separate module.

May 13, 2009 | by

Discrete variables in LS-OPT

Starting version 3.0, LS-OPT supports the definition of discrete variables. Discrete type of design parameters are helpful when there is a need to find the optimum values from a “set” of values. A good example would be the choice of element formulation. The possible values for LS-DYNA for a quad can only be a subset…

February 9, 2009 | by

Fast Debug of LS-OPT driven Optimization Problems

LS-OPT is widely used to optimize designs or parameters using a number of experiments obtained by running LS-DYNA simulations. The number of experiments (simulations) per iteration is dependent on the number of variables defined in LS-OPT in addition to the type of point-selection (DOPT, LatinHyperCube, etc). When a large number of simulations are involved, it…

January 28, 2009 | by

Free Limited LS-DYNA Version to Assist Displaced Workers

LSTC has introduced a free limited LS-DYNA version for U.S. unemployed LS-DYNA users as a result of the current poor economic conditions. A free LS-DYNA course may also be introduced in the coming months. Please contact Marsha Victory at 925 449 2500 or send her an email at

December 13, 2008 | by

Multi Solver Run in LS-OPT

In LS-OPT, one can run a multi-disciplinary optimiztion or a multi-solver type optimization problem, where the variables can be shared among the different solvers. In performing DOE or any optimization using LS-OPT, it is important that consistent experimental points are used in the evaluations. To ensure this, one can use solver experiment duplicate solver_1 command…

November 11, 2008 | by

Packing LS-DYNA Input Files for Easy Distribution (v1.1a)

In a previous post about a simple Python script that scans a LS-DYNA input file to package all INCLUDED files recursively so the entire model can be compressed and sent to the recipient. Based on some new suggestions, largely by Brian Wainscott, I have attached a revised script that handles the included files a little…

October 15, 2008 | by

Damage modeling using GURSON

Material parameter identification of GURSON material requires a process of fitting using an optimization package such as LS-OPT to match against a measured response such as a test. Following is a stress-strain curve that is achieved as a process of parameter identification using LS-OPT and LS-DYNA.

October 13, 2008 | by

Optimizing monotonically increasing load curves

In cases where a monotonically increasing curve such as pressure_vs_leakage in *AIRBAG or effective_stress_vs_effective_strain in plasticity models in *MAT are to be parametrically identified by an optimization software such as LS-OPT to match against a physical test, it is important to ensure that the points identified by LS-OPT satisfy the non-negative slope. To satisfy this,…

October 9, 2008 | by

Characterizing plasticity material models using data from test

It is common to perform a uni-axial tensile test on a material sample to generate stress-strain curve for use in numerical models in LS-DYNA. The problem frequently encountered by analysts is the cleaning of the test data that is usually noisy. I recently wrote a small Python utility that takes any test generated force-deflection curve…

October 9, 2008 | by

Termination due to Added Mass

In older versions of LS-DYNA (950 and lower) , when mass-scaling was active and over the course of the simulation when the percentage of added mass was greater than ENDMASS in *CONTROL_TERMINATION , LS-DYNA would terminate that job with no additional message. However, recent versions of LS-DYNA terminate the job AND provide a list of…

September 4, 2008 | by