A recent investigation to determine the best viewing configuration for any arbitrary model required me to understand the ‘QUAT’ that appears in LS-PREPOST every time you rotate a model or change its view. If you are interested to understand this, you can view this Powerpoint document for more information.
While working on a simulation model, it is often very convenient for oneself or to others to make necessary notes that documents the changes in the input file. While each person’s method of documenting changes in short sentences could vary, a formal pattern of documentation could help unify the documentation so anyone can easily follow…
In an earlier post on CONTACT INTERIOR , we saw how adding interior contact can help prevent negative volumes. An additional method that is available in LS-DYNA is the use of SET_SEGMENT_GENERAL to generate the interior segments of solids. When a list of parts are defined using PART_SLDIO in the SET_SEGMENT_GENERAL, LS-DYNA generates both external…
Here is a TAR file that consists of a simple setup to demonstrate TIEBREAK interface contact in LS-DYNA. The example can be used under TENSION, COMPRESSION, TORSION and PEELING type of load. acumulatori camere constructii interioare avion romania spania cablu electric camera digitala canon componente motor sofer curier plante de decor excursii roma montaj faianta…
Domain decomposition is central to MPP-LSDYNA as it determines the final load balance on each of the compute nodes. The default (and most widely used) decomposition method is the Recursive Coordinate Bisection (RCB) which recursively halves the model using the longest dimension of the input model. army assessment risk dodge car accessory pipe water ochelari…
Under large compressive forces, elements belonging to either Foams, Honeycombs and Rubbers tend to invert causing numerical instabilities. To avoid such difficulties, which is one of the primary causes of simulation waste (unusable simulation results), a good set of modeling practices are first necessary as outlined in an earlier post . As an added protected…
A simple variable ‘DCOMP’ can be used in *DATABASE_EXTENT_BINARY keyword to suppress unwanted information about rigidbodies to help reduce the size of D3PLOT files. Please note that this feature has no effect if your model has only deformable elements.
In an earlier post on decomposition and region domains we saw how customized PFILE can be used to improve load balancing. Two new commands “aledist” and “sphdist” can now be included in “PFILE” that allows LS-DYNA to distribute the ALE and SPH information across all processors. This will greatly improve the load balancing when using…
As of today, D3VIEW 2.0beta has been officially released in a closed environment. Update Due to heavy traffic, the site is currently down. Should be up shortly.
Attached is a simple Excel sheet that can be used to quickly evaluate the timestep calculated by LS-DYNA for solids, beams and shells. It must be noted that for solid elements, Q is based on the C1 (default = 0.06) only. timestep.xls Update For solid elements using MAT_SPOTWELD, LS-DYNA uses a slightly different method of…
