Study on Estimation Method for Seismic Safety Margin of 3D Piping System With Degradation: Establishing Elasto-Plastic Analysis Model

The authors have proposed an analytical model by which they can simulate the experimental results of a piping system with full circumferential 48% thinning at an elbow or two elbows. A series of elasto-plastic analyses has been carried out in order to investigate the experimental behavior of the piping system. Dynamic analyses describe the ratcheting behavior and the average amplitude of the opening-closing displacement at elbows relatively well. And then static analyses describe ratcheting and ovaling of the cross section of pipes fairy well.