The Slip Velocity node facilitates a simplified form of slip friction modeling, which can be used in the case that the direction and speed of the sliding is known. In this case, there is no need to solve for the friction forces and slip orientation.
The selection in the Slip Velocity node is the same as that of its parent
Contact node. There can only be one
Slip Velocity node under a specific
Contact node.
The Slip Velocity and
Friction nodes are mutually exclusive.
The Slip Velocity node is only available with some COMSOL products (see
https://www.comsol.com/products/specifications/).
Select a Friction model —
Coulomb,
Exponential dynamic Coulomb, or
User defined. Since the velocity is prescribed, a velocity dependent friction model can be used also in a stationary analysis.
Enter a Cohesion sliding resistance Tcohe to provide an offset to the tangential traction.
Independently, you can enter a Maximum tangential traction Tt,max. This is the maximum tangential traction, independent of the contact pressure. The default expression is
Inf, indicating that no limit on the tangential traction is active.
When Friction model is set to
User defined, enter an expression to define
Tt,crit. This expression can depend on any quantity. However, the implementation of the friction model is only correct if
Tt,crit does not depend implicitly on the current friction force.
Enter the relative velocity between the destination and source boundaries, vslip. The velocity is expressed in the coordinate system provided in the
Coordinate System Selection section, interpreted on the destination boundary.
Select Compute frictional dissipation to compute and store to the energy dissipated by friction. This adds one extra set of state variables to be stored. The integration is explicit, and adds only marginally to the computational cost.
Physics tab with Contact selected in the Model Builder tree: