About Mechanical Contact Properties

In a mechanical contact simulation the interaction between contacting bodies is defined by assigning a contact property model to a contact interaction (see Contact Properties for General Contact in Abaqus/Standard, Assigning Contact Properties for Contact Pairs in Abaqus/Standard, Assigning Contact Properties for General Contact in Abaqus/Explicit, and Assigning Contact Properties for Contact Pairs in Abaqus/Explicit for details). Mechanical contact property models:

  • may include a constitutive model for the contact pressure-overclosure relationship that governs the motion of the surfaces;

  • may include a damping model that defines forces resisting the relative motions of the contacting surfaces;

  • may include a friction model that defines the force resisting the relative tangential motion of the surfaces;

  • may include a constitutive model in which you define the normal and tangential behavior in user subroutine UINTER in Abaqus/Standard;

  • may include a constitutive model in which you define the normal and tangential behavior in user subroutine VUINTER in Abaqus/Explicit when using the contact pair algorithm;

  • may include a constitutive model in which you define the normal and tangential behavior in user subroutine VUINTERACTION in Abaqus/Explicit when using the general contact algorithm;

  • in Abaqus/Standard may include a constitutive model for the penetration of fluid between two contacting surfaces;

  • in Abaqus/Standard may include a constitutive model for the interaction of debonded surfaces;

  • in Abaqus/Explicit may include a constitutive model that simulates the failure of bonds connecting the interacting bodies; and

  • may include surface-based cohesive behavior that allows modeling of delamination of bonds or “sticky” contact using progressive damage evolution models.

This section provides a general outline of how to define the components of a mechanical contact property model. Specific details about the different components of the contact property models and the algorithms used for the contact calculations are found in other sections of this chapter.

See Also
About Contact Interactions
About Contact Pairs in Abaqus/Standard
Assigning Contact Properties for General Contact in Abaqus/Explicit
Assigning Contact Properties for Contact Pairs in Abaqus/Explicit
Contact Pressure-Overclosure Relationships
Contact Damping
Contact Blockage
Frictional Behavior
User-Defined Interfacial Constitutive Behavior
Interaction of Debonded Surfaces
Breakable Bonds
Contact Cohesive Behavior
In Other Guides
*SURFACE INTERACTION

Defining the Contact Property Model

There are different methods for defining the components of a mechanical contact property model.

Defining the Contact Pressure-Overclosure Relationship

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.

Defining a Friction Model

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.

Defining Contact Cohesive 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.

Defining a Surface Interaction Model with Damping between the Surfaces

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.

Defining Contact Blockage in Abaqus/Explicit

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.

User-Defined Interfacial Constitutive Behavior

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.

Defining a Pressure Penetration Load in Abaqus/Standard

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.

Defining CZone Crush Characteristics in Abaqus/Explicit

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.

Defining the Interaction of Debonded Surfaces in Abaqus/Standard

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.

Defining Breakable Bonds in Abaqus/Explicit

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.