配管系の弾塑性応答時の履歴減衰推定

抄録

When piping systems respond under the elastic-plastic region, it is known that the increasing of hysteresis damping and the decreasing of the dominant frequency would occur due to the plastic deformation. But there are few studies that attempt to estimate them quantitatively from the actual excitation test data of piping systems. In this paper, the hysteresis damping ratios and the dominant frequencies under inelastic response behavior region are estimated based on the test data obtained by one-directional shaking table tests on a 3D piping system model. In addition, the strains which were caused on the piping system model are also checked, and correlated with the estimated hysteresis damping ratios. As a result, the estimated damping ratio was about 4% when the one elbow in the piping system model reached to the inelastic region, with about 0.6% strain range. The hysteresis damping ratio was up to more than 10% under the high input acceleration level, when the two main elbows reached to the inelastic region. The dominant frequency was decreased about 3~8% when the one elbow in the piping system model reached to the inelastic region. The decreasing ratio was about 14~18% under the higher input acceleration level.