•Dynamic Friction Coefficient: Specifies a dynamic friction coefficient for the contact friction force.
Figure 1 Relationship between relative velocity and friction coefficient
•More: Specifies some friction coefficients for the contact friction force.
Figure 2 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. If the relative velocity between a contact pair is greater than “Static Threshold Velocity” and less than this value, the friction coefficient is defined as following.
•Static Friction Coefficient: Specifies a static friction coefficient.
Figure 3 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 Figure 3.