Visualizing LS-OPT®Sampling points in d3VIEW

LS-OPT offers several sampling schemes among which D-OPT, Space filling and Latin Hypercube are among the popular schemes. Using d3VIEW’s LS-OPT output parser, the three schemes were used to generate experiments for variables that ranged from a mininum of 0.0 and a maximum of 1.0. Following images compare the distribution of the samples for all…

November 6, 2018 | by

LS-DYNA Conference 2014

The 13th LS-DYNA  conference was the largest conference which was attended by over 650 attendees from around the world. You can find the papers from the conference here Following are some pictures from the hugely successful LS-DYNA conference recently held in Dearborn, Detroit. 1. Dr. John Hallquist, President and CEO of LSTC,  presenting the latest developments…

June 13, 2014 | by

Commenting LS-DYNA Keyword Blocks

A clever way to comment out blocks of keyword can be easily achieved using the *COMMENT keyword. Example: In the following example, the keyword *MAT_ELASTIC and all cards until the next keyword is commented out by simply adding a *COMMENT in front of it. *MAT_ELASTIC 1, 1.0e-9, 210.00, 0.3 *SOME_OTHER_KEYWORD …. …. to *COMMENT*MAT_ELASTIC 1,…

April 24, 2014 | by

Cohesive Element Timestep

Cohesive material models are well suited for representing the behavior of structural and non-structural adhesives that is now increasingly used. To accommodate extreme dimensions of the element such as zero volume or near-zero volume, the timestep of the Cohesive element is based on the characteristic stiffness and mass of the element instead of the characteristic…

March 11, 2014 | by

Parameter DIR in DEFINE_COORDINATE_SYSTEM

In earlier versions of LS-DYNA, the axis N1-N2 was always set as the local-x but in new versions (since LS-DYNA v971), the N1-N2 vector can be configured to be either X,Y,or Z. Image below shows the influence of DIR in the local system set up.

December 9, 2013 | by

Recommended settings for Spotwelds

When using spotwelds, there are several non-default parameters that are recommended to improve the spotweld behavior and model robustness. Following are some of the important parameters: 1. CONTACT_CONTACT/OUTSEG This parameter helps to get a list of all spotweld nodes and the parent segment information. This is helpful in earlier designs to ensure the spotweld node…

October 25, 2013 | by

Total Mass, Physical Mass and Added Mass

LS-DYNA reports three types of mass information for the model. The total mass and the physical mass is the same which is the mass of the model before any added mass is calculated. Added mass is the mass required to add to the nodes for all elements whose timestep is below abs(DT2MS). The effective mass…

May 2, 2013 | by

Air particles and relaxation when using Particle based airbag inflation

When using particle based airbag inflation method using *AIRBAG_PARTICLE, the initial air in the airbag can be modeled using control-volume approach or as particles. This is governed by the parameter IAIR. When IAIR=1, a uniform-pressure model is used to specify the initial atmospheric temperature inside the bag. When IAIR=2, one can specify the number of…

April 29, 2013 | by