Effect of the plasticity of pipe and support on the seismic response of piping systems

Abstract

This paper describes the results of seismic analyses conducted to clarify the effects of the plasticity of the pipe and its supports on the seismic response of the entire piping system. First, a study (Study 1) was performed to evaluate the effects of the plasticity of the pipe and its support independently, and of both the pipe and the support on the response of the entire piping system. Second, another study (Study 2) was performed to evaluate the effects of the magnitude of the yield load and post-yield stiffness on the restoring force characteristics of the supports. Study 1 produced remarkable insight on the seismic design of piping systems. The plasticity of the pipe and the support significantly reduced the support load and the elbow strain. In particular, the effect of the plasticity of the support was larger. Study 2 showed that the yield load of the support significantly affects the response of the piping system, whereas the post-yield stiffness does not affect much compared with the yield load.