LS-DYNA 971 Release 4 Manual Available for Download

You can download the LS-DYNA 971 r4 Manual (PDF, 11.5 Mb)

Update The broken link has been fixed

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.

Mass calculations for Discrete Beams

Discrete beams, like discrete springs, require valid mass at the nodes to compute the timestep. Unlike continuum based elements, the length of the discrete beams, are not used in the timestep calculations. Hence realistic density in the discrete beam material model must be used. There are two methods this can be achived.

Density (RHO) in the material card is not equal 1.0
When the density in the material is anything but unity, it is required to set appropriate value for the parameter “VOL” in the SECTION_BEAM keyword. When VOL is non-zero and RHO in the material card is not unity, LS-DYNA computes the mass by simply multiplying these two parameters and lumps it equally to the two nodes that make up the discrete beam.

Density (RHO) in the material is equal to 1.0
Whne the density in the material card is equal to unity, LS-DYNA uses the VOL parameter in the SECTION_BEAM keyword as the mass value and lumps them to the beam-nodes.

For non-zero and zero-length discrete beams, both methods are valid but methods must yield realistic mass to provide a reasonable timestep.