Aspects of Contact Dynamics Relevant to Wear

An overview is provided of the generation and modeling of dynamic loads and motions that can occur at sliding contacts. Dynamic loads can be generated by disturbances within the contact or can be transmitted from remote locations within a system. The presence of contact vibrations can add fluctuating loads to the average loads that must be supported, potentially increasing wear. Due to the nonlinear character of most contacts, dynamic loads can affect both the instantaneous motions and the average configuration of a sliding system. These motions can increase or decrease wear rates, depending on the circumstances. Sliding contacts exhibit mechanical stiffness and damping behavior, often ignored, which, in conjunction with the loading and overall system characteristics, determine contact loads and motions. Furthermore, the running in and wear of surfaces can alter the dynamic characteristics of both the contact and the sliding system.