What are the type of contacts commonly used in DYNA?
Single surface. These contact types are the most widely used contact options in LS-DYNA, especially for crashworthiness applications. With these types, the slave surface is typically defined as a list of part ID’s. No master surface is defined.
How contact works in LS-DYNA?
How Contact Works. In LS-DYNA, a contact is defined by identifying (via parts, part sets, segment sets, and/or node sets) what locations are to be checked for potential penetration of a slave node through a master segment. A search for penetrations, using any of a number of different algorithms, is made every time step …
What is soft in LS-DYNA?
Soft=1 calculates contact stiffness based on stability considerations taking into account the timestep. In other words, you can liken Soft=1 contact to a group of simple spring-mass systems, each with a Courant timestep matched to the actual timestep used in the simulation.
What is contact thickness?
For each contact node, the contact thickness is set to the thickness of the shell element that contains it. If SFST/SFMT or SFT are set, scale the thickness (with SFT overriding SFST/SFMT). If SSTHK is 0 and the contact is single surface, limit thickness to 40% of the minimum edge length of the element.
How many contact types are there in LS-DYNA?
In particular, LS-DYNA has more than 70 different contact types, and each type supports numerous options and special settings. While this generous selection guarantees extreme flexibility for the contact definition, it also requires a great deal of knowledge on the user’s side to make proper use of it.
Where can I find the LS-DYNA user’s manual?
LS-DYNA USER’S MANUAL LS-DYNA USER’S MANUAL Nonlinear Dynamic Analysis of Structures May 1999 Version 950 Copyright © 1989-1999 LIVERMORE SOFTWARE TECHNOLOGY CORPORATION All Rights Reserved Mailing Address: Livermore Software Technology Corporation 2876 Waverley Way Livermore, California 94550-1740 Support Address:
Why does my LS-DYNA contact interface not work?
Sometimes automatic contact interfaces appear not to work because this contact threshold is reached early in the simulation. This often occurs if extremely thin shell elements are included in the contact surface.
How are initial penetrations eliminated in LS-DYNA?
LS-DYNA will make one pass to eliminate any detected initial penetrations by moving the penetrating slave nodes to the master surface. Not all initial penetrations will necessarily be removed and this can lead to nonphysical contact behavior. Time taken in setting up an accurate initial geometry is always time well spent.
