Meaning
Resistance forces occurring between sliding contact surfaces determine the power loss and mechanical wear of moving joints. The coefficient of dynamic friction must be carefully measured to predict structural damping and actuator loads. This value remains lower than the static friction limit.
Motion State
Kinetic behavior governed by sliding interfaces is highly dependent on velocity. The system operates under continuous slip conditions when external forces exceed the static breakaway limit. Measurements show that the force remains relatively constant across a moderate speed range.
If the velocity increases beyond this range, localized temperature changes can alter the material properties.
Interface Behavior
Physical surface interactions at the contact points undergo continuous shear deformation during motion. The roughness of the mating materials creates microscopic contact spots that shear and reform constantly. Low-friction coatings help minimize this effect by reducing the shear strength of the boundary layer.
Heat Generation
Mechanical energy converted to thermal energy at the sliding junction raises the local temperature. This heat dissipation is critical for electronic assemblies because thermal expansion can cause structural distortion. The temperature rise is calculated from the normal load, the sliding speed, and the dynamic friction coefficient of the interface materials.
Excessive temperature increases the risk of material degradation. If the thermal load is too high, the localized bonding of materials may lead to interface seizure or galling.
