Specifies some friction coefficients for the contact friction force as shown in Figure 1.
Figure 1 Friction Definition dialog box
•Static Threshold Velocity: If the relative velocity between a contact pair is less than this value, the friction coefficient is defined as following.
•Dynamic Threshold Velocity: If the relative velocity between a contact pair is greater than:
•This value, the friction coefficient is same as the specified dynamic friction coefficient.
•“Static Threshold Velocity” and less than this value, the friction coefficient is defined as following.
•Static Friction Coefficient: Specifies a static friction coefficient.
•Maximum Friction Force: If this is checked, the contact friction force is limited to this value.
Figure 2 Relationship between relative velocity and friction coefficient
The friction force of contact elements is determined by the following equations.
Where,
, 
and 
are the contact normal force, the
friction coefficient and the maximum friction force, respectively.
The friction coefficient of is determined by a relative and tangential
velocity on the contact point as shown in Figure2.