Creeping motion characteristics due to bulk wave excitation in an elastic half-space

In this work, the contact problem between a preloaded rigid surface against a restrained elastic half-space is considered under wave excitation. The half-space is assumed to be bonded imperfectly to the rigid surface, and subjected to external tractions and bulk waves. Under incident bulk wave excitation at the contact, we study the creeping motion of the preloaded rigid surface. Two possible local regions at the interface are considered, namely slip region, and region of separation, which are described by the corresponding boundary conditions and inequalities at the interface. With these considerations, creeping motion characteristics and interface conditions are obtained analytically and discussed. The effects of interface imperfection, wave parameters, and preload tractions are studied numerically. The creeping motion is found to be affected significantly by nature of the imperfection. In addition, creep motion is also analyzed considering friction at the interface. These aspects have potential applications in ultrasonic devices for micro-positioning and micro-motion control.