動的荷重を受ける配管の塑性崩壊に関する基礎的研究
概要
According to experimental observations, as the failure modes of piping in nuclear power plants caused by large seismic motion, ratchet collapse was observed. Ratchet collapse is the collapse which is followed by ratchet deformation. However, the mechanism of ratchet collapse under the large seismic load is not so clear. In order to clarify ratchet collapse, it is important to examine ratchet deformation and collapse at first. Ratchet deformation occurrence condition and mechanism have already been clear. In this study, in order to clarify collapse under dynamic loads, authors conducted experiments and analyses of beams which simulates piping under large seismic motion. As the results, authors confirmed that collapse occurrence conditions are strongly affected by the frequency ratio, frequency of input wave divided by natural frequency. Moreover, the mechanism of collapse was explained from the view point of energy transfer from input loading to the beam.
