Numerical Simulation of Impact Vibration Caused by Spatial Gaps Between Piping and Piping Support in High-Temperature Piping Systems

Abstract In high-temperature piping, a gap is provided in the piping support part to release the thermal expansion of the piping. As a result, impact vibration occurs during an earthquake, causing impact loads and nonlinear vibrations. This study proposes an analysis method that can simulate the impact phenomenon from moment to moment and consider the influence of the structural and vibrational characteristics of the impacted object, rather than an analysis method that uses a restitution coefficient that does not take into account the temporal nature of the impact process. In order to analyze the impact vibration of the piping system with gap, the mechanical model of the impact phenomenon is expressed in a one-degree-of-freedom system of mass-spring and an analysis model using a beam element as piping is created. The time history response of the vibrating piping colliding with the piping support is computed by Runge-Kutta method. Using this proposed method, the influence of the gap size (clearance) on the seismic design and vibration characteristics of the piping is investigated. As a result, it was found that the vibration response changed rapidly depending on the gap size (clearance). This change in vibration response was noticeable during resonance. It is necessary to clarify the gap size (clearance) which is the threshold for change.