Study on strength of piping components under elastic-plastic behavior due to seismic loading

摘要

In this study, pipe material tests, pipe component tests and FEM simulation for pipe components were performed. Material test was performed to clarify the ratchet fatigue strength of the pipe material itself. Pipe component tests was performed to clarify fatigue life which occurs under vrious load applications and failure mode under static cyclic and dynamic loading conditions. These experimental results suggest that the failure mode of piping components under seismic loaidng is fatigue with ratchet and that the reduced fatigue life can be estimated by considering the ductility consumption of material due to accumulated ratchet strain. Based on the nature of the strain and failure modes due to seismic loading, it is reconmmendable that the stress due to seismic inertia force should be classified as secondary stress and seismic design criteria should be defined with view to preventing fatigue failure.