Starting in LS-DYNA version 970 and later, we can now use expressions instead of digitized values to define an XY curve. Optionally, the expressions can refer to other curves which could be defined using either digitized points or using expressions themselves. Here is an example of its usage:
Polynomial Expressions
You can define a generic polynomial [...]
Archive for September, 2006
In contact-impact interactions, friction plays an important role in accurately capturing the sliding behavior. In LS-DYNA, the coulomb treatment of friction is used where a static and a dynamic friction can be defined which are used to determine the shear force while resisting penetration. By default, all [...]
Contact Thickness in Single Surface Contact
Published by September 25th, 2006 in LS-DYNA Contact. 2 CommentsSingle surface contacts have dramatically eased the way we currently model the contact-impact treatment for complicated simulation models in LS-DYNA. One of the important considerations is the final thickness used by contact algorithms especially for shell elements. By default, LS-DYNA considers the minimum of thickness specified in the *SECTION_SHELL or from *ELEMENT_SHELL_THICKNESS and the 40% [...]
Identifying Problem Areas for Poorly Converging Implicit Solutions
Published by September 21st, 2006 in LS-DYNA Bytes and LS-DYNA Implicit. 2 CommentsFor non or poorly converging implicit solutions, the parameter D3ITCTL parameter in *CONTROL_IMPLICIT_SOLUTION may come handy to isolate regions of interest. When D3ITCTL is non-zero, LS-DYNA outputs the model information at each Iterative step into a binary file named D3ITER which is in the same format as D3PLOT. The number of steps for which the [...]
Mapping of Deformed Nodal Coordinates for SubSystem/Component Analysis
Published by September 21st, 2006 in LS-DYNA Output. 2 CommentsSeveral analyses sometimes requires the mapping of nodal positions (coordinates) from a previous run for use in current run. For single component this is a rather easy task since it just involves writing a DYNAIN file for part(s) of interest using *INTEFACE_SPRINGBACK_LSDYNA keyword which would consist of final deformed nodal coordinates and element history [...]
Number of Shell History Variables in *INTERFACE_SPRINGBACK
Published by September 19th, 2006 in LS-DYNA Elements and LS-DYNA Output. 0 Comments*INTERFACE_SPRINGBACK provides an easy way to store a part’s state at the end of a simulation for later use. The part’s state consists of element history variables such as stress and strain tensor (in the form of *INITIAL_STRESS/*INITIAL_STRAIN) and also nodal values such as its final coordinates (*NODE). Optionally, when using the THICKNESS option, it [...]
Recent Comments