ACCEPTANCE CRITERION OF DUCTILE FAILURE AND PLASTIC COLLAPSE FOR SAFE-SHUTDOWN EARTHQUAKES USING NONLINEAR DYNAMIC ANALYSIS

摘要

We investigated the ductility factors of nonlinear inelastic SDOF systems at Level D Service Limits "using elastic analysis" in ASME BPVC Sec. ffl, and confirmed that the ductility factor depends on the natural frequencies of the systems, seismic motions and constant loads. Based on the above results, an acceptance criterion of components to prevent ductile failure and plastic collapse is proposed. The criterion is given as a limit of ductility factor for Level D Service Limits "using plastic analysis". The proposed limit of ductility factor allows single state for nonlinear inelastic systems, and is not depending on the natural frequencies of the systems, seismic motions and constant loads.