About Mechanical Contact Properties

The default contact pressure-overclosure relationship used by Abaqus is referred to as the “hard” contact model. Hard contact implies that:

• the surfaces transmit no contact pressure unless the nodes of the secondary surface contact the main surface;

• no penetration is allowed at each constraint location (depending on the constraint enforcement method used, this condition will either be strictly satisfied or approximated);

• there is no limit to the magnitude of contact pressure that can be transmitted when the surfaces are in contact.

You can define a nondefault pressure-overclosure relationship for a surface interaction. The various pressure-overclosure relationships available in Abaqus are discussed in Contact Pressure-Overclosure Relationships, and the constraint methods available to enforce these relationships are discussed in Contact Constraint Enforcement Methods in Abaqus/Standard.

By default, Abaqus assumes that contact between surfaces is frictionless. You can include a friction model as part of a surface interaction definition.

Details of the various friction models available in Abaqus are discussed in Frictional Behavior.

You can define contact cohesive behavior to model delamination of initially bonded surfaces or to model “sticky” contact between parts that are initially separated but bond on coming into contact, with the possibility that the bond may undergo progressive damage and fail.

Contact cohesive behavior is modeled within the general contact framework in Abaqus/Explicit and within the general contact or contact pair framework in Abaqus/Standard. Details of the contact cohesive behavior model are discussed in Contact Cohesive Behavior.

You can define damping forces to oppose the relative motion between the interacting surfaces.

In Abaqus/Standard the specified contact damping affects the motion in the normal direction only, whereas in Abaqus/Explicit contact damping can affect both the relative tangential motion and the motion normal to the surfaces.

The details of the contact damping model are discussed in Contact Damping.

In Abaqus/Explicit you can control the combination of surfaces that can cause blockage of flow out of a surface-based fluid cavity. The details of contact blockage are discussed in Contact Blockage.

Instead of choosing one or some combination of the various interfacial behavior models that are available in Abaqus, you can define any special or proprietary interfacial constitutive behavior through a user subroutine. In Abaqus/Standard you can use the subroutine UINTER; whereas in Abaqus/Explicit you can use VUINTER if you are using the contact pair algorithm and VUINTERACTION if you are using the general contact algorithm.

In Abaqus/Explicit a penalty enforcement of the contact constraint must be used for interacting surfaces whose interfacial behavior is governed by VUINTER or VUINTERACTION.

Details of the definition of a user-defined interfacial constitutive behavior are discussed in User-Defined Interfacial Constitutive Behavior.

You can define pressure penetration loads to simulate the penetration of fluid between two contacting surfaces in Abaqus/Standard. The details of the pressure penetration model are discussed in Fluid Pressure Penetration Loads.

The CZone capability in Abaqus/Explicit integrates material, element, and contact modeling aspects to simulate crushing of laminated composites. This capability is discussed in CZone Analysis.

You can allow two initially bonded surfaces to debond in Abaqus/Standard, as discussed in Crack Propagation Analysis. The details of the contact interaction model after debonding are discussed in Interaction of Debonded Surfaces.

In Abaqus/Explicit you can define breakable bonds that connect the interacting surfaces. The kinematic contact pair algorithm must be used when defining breakable bonds.

The breakable bonds affect both the relative tangential motion and the motion normal to the surfaces. Breakable bonds cannot be used with analytical rigid surfaces. The details of the breakable bond model, known as the spot weld model, are discussed in Breakable Bonds.