Assigning Contact Properties
The default contact property model in Abaqus/Standard assumes “hard” contact in the normal direction, no friction, no thermal interactions, etc. You can assign a nondefault contact property definition (surface interaction) to specified regions of the general contact domain. These regions are identified with surface names or material names. For example, contact property ContProp_A can be assigned to the combination of surface Surf_1 and the surface whose underlying elements have a section assignment with material Rubber. Surfaces associated with Surf_1 and Rubber can span multiple parts.
Contact properties for general contact in Abaqus/Standard are assigned at the beginning of the analysis and cannot be modified across steps, with an exception for changes to the friction model, as discussed below.
The surface names used to specify the regions where nondefault contact properties should be assigned do not have to correspond to the surface names used to specify the general contact domain. In many cases the contact interaction will be defined for a large domain, while nondefault contact properties will be assigned to a subset of this domain. Any contact property assignments for regions that fall outside of the general contact domain will be ignored. The last assignment will take precedence if the specified regions overlap.
Changing Friction Properties during an Analysis
The friction properties associated with a given named surface interaction definition can be modified in any particular step of an Abaqus/Standard analysis, as discussed in Changing Friction Properties during an Abaqus/Standard Analysis.
Example
The following contact property assignments are specified below as model data in a general contact analysis:
-
a global assignment of
contProp1to the entire general contact domain; -
a local assignment of
contProp2to self-contact forsurf1; -
a local assignment of the default Abaqus contact property to contact between
surf2andsurf3; and -
a local assignment of
contProp3to contact between the entire contact domain andsurf4. The friction coefficient forcontProp3is reset from the initial value of 0.20 to 0.05 in the second step.
SURFACE INTERACTION, NAME=contProp1 FRICTION 0.1 SURFACE INTERACTION, NAME=contProp2 FRICTION 0.15 SURFACE INTERACTION, NAME=contProp3 FRICTION 0.20 CONTACT CONTACT INCLUSIONS, ALL EXTERIOR CONTACT PROPERTY ASSIGNMENT , , contProp1 surf1, surf1, contProp2 surf2, surf3, , surf4, contProp3 … STEP Step1 STATIC … END STEP STEP Step2 STATIC … CHANGE FRICTION, INTERACTION NAME=contProp3 FRICTION 0.05 END STEP