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contact_geometry index geometry_entity_item geometry_entity_index

This record specifies a contact geometry. The allowed geometries and their material outward normals are listed below

This normal can be switched sign by setting the contact_geometry_switch with the same index to -yes.

In stead of geometries, also contact with all elements will be checked. Only contact with the elements -bar2, -tria3, -quad4 and -tet4 can be detected. The outer boundary of the elements should be specified by node_boundary records. Often it is sufficient to apply node_boundary records on the body with the coarsest mesh; if the meshes of the contacting bodies are of the same size however, you should specify node_boundary records for both contacting bodies.

The time steps should be such small, that contacter nodes penetrate the other elements only in small steps.

If a contact_geometry is used, then the contacter node should also be within the tolerance of the geometrical entity to be noticed!

If contact is detected, normal contact forces of size contact_penalty_velocity $*$ penetration are generated between the contacting node and the other element. Moreover, also a frictional force of size friction $*$ normal force is generated (see contact_friction).

You need more iterations, see control_timestep_iterations, then normal; say 10 or so.

As an alternative to the contact algorithm, see node_slide.


next up previous contents
Next: contact_geometry_switch index switch Up: Input: data part Previous: contact_friction friction   Contents
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1999-04-23