Development of Seismic Design Method for Piping System Supported by Elastoplastic Damper. 2nd Report. Vibration Test of One-Dimensional Piping Model and Its Response Analysis.

Components and piping systems in current nuclear power plants and chemical plants utilize many supports to maintain safety and reliability against earthquakes. However, these supports are rigid and have a slight energy-dissipating effect. It is well known that application of high damping supports to the piping system is very effective to reduce seismic response. In this study, we investigate the design method of the elastoplastic damper [energy absorber (EAB)] and the seismic design method for the piping system supported by the EAB. Our final goal is to develop a technology for applying the EAB to the piping system of an actual plant. In this paper, the vibration test results of a one-dimensional piping model are presented. From the test results, it is confirmed that the EAB has the large energy-dissipating effect and is effective to reduce the seismic response of the piping system. Furthermore, a seismic design method for the piping system, which is the response spectrum mode superposition method that uses each modal damping and needs the iterative calculation about the EAB displacement, is developed.