Rigidwalls are analytical representations of surfaces or volumes that are frequently used to represent stiff structures that are either stationary or in motion. Viewing of such analytical definitions in D3PLOTs were not possible for most rigidwalls. A new option in LS-DYNA named DISPLAY that can now be used to any *RIGIDWALL definitions which causes LS-DYNA [...]
Archive for the 'LS-DYNA Elements' Category
*RIGIDWALL_{DISPLAY} option
Published by May 3rd, 2010 in LS-DYNA Bytes and LS-DYNA Elements. 0 CommentsMass calculations for Discrete Beams
Published by May 13th, 2009 in LS-DYNA Bytes and LS-DYNA Elements. 0 CommentsDiscrete 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 [...]
Membrane Thinning in Shell Elements
Published by November 4th, 2007 in LS-DYNA Bytes and LS-DYNA Elements. 0 CommentsIn 2D shell elements, the stress in the normal (fiber) direction is iteratively reduced to zero to meet the plane-stress condition. The strains are however nonzero in the fiber direction and will be linear though the thickness. Under membrane straining, LS-DYNA allows an option to account for the reduction in the shell thickness in the [...]
Mesh Refinement Studies Involving Shell Elements
Published by August 28th, 2007 in LS-DYNA Bytes and LS-DYNA Elements. 2 CommentsIn many situations, we tend to change the mesh density to study its effect on simulation responses. Two issues things that are seldom addressed are the contact thickness and the mass-scaling which blend in with the true effects of the mesh refinement. As stated in some of the earlier posts, LS-DYNA computes the contact thickness [...]
Default element sorting for 3-noded shell elements uses the collapsed BT formulation which is not recommended but is maintained for backward compatibility. The first option that LS-DYNA offers is to sort these elements to use a C0 triangular shell formulation which may provide better answers than the default formulation. LS-DYNA 971 (R3 and later) now [...]
Bulk Viscosity for Shells and Solids in LS-DYNA
Published by January 26th, 2007 in LS-DYNA Bytes and LS-DYNA Elements. 4 CommentsIn any wave propagation code, such as LS-DYNA, which belongs to a family of ‘Hydro’ codes, bulk viscosity is essential to treat shocks. Smooth initial data can lead into shock discontinuities and if left untreated can result in severe instabilities. LS-DYNA has the capability (performed by default) to automatically detect the shocks and treat them [...]
Recent Comments