Abstract
In the piping design of nuclear power plants and chemical plants, a clearance is required between the pipe and the supporting part that supports it so that the pipe can move in the pipe axial direction in order to allow thermal expansion of the pipe in the pipe axial direction. Due to the clearance, the supporting part of the pipe becomes a loose structure with gap. Hence, the structure causes impact vibration during earthquakes, resulting in dissipation damping and impact load. In this study, since the vibration mode of the piping changes before and after the collision phenomenon of the piping, we propose an analytical model of piping impact vibration using a beam model for the pipe and a spring-mass system model for the support part. In particular, we discuss the relationship between the vibration of the supporting part and the coefficient of restitution by using the one-degree-of-freedom spring-mass system model of the supporting part, which is a main part composing the proposed analytical model for impact vibration of piping systems.
