管支持部の摩擦力を考慮した加速度応答スペクトルの作成手法

（線形応答解析に基づく等価減衰の検討）

抄録

Simple support structures such as U-bolts are used for the low-class piping based on the constant pitch span method. Recently, the integrity of the piping is required during the earthquake, and the demand for safety in nuclear power plants has been increased. As a result, the high seismic resistance has also been required for the low-class piping. In the response analysis, the support structure is only constrained the radial displacement, and the longitudinal displacement is not constrained. Depending on the routing of the piping, a large longitudinal response displacement may occur, and the structural integrity of the pipes and the support structures may not be ensured. Therefore, measures have been taken to add or reinforce support structures. In practice, pipes are subjected to the longitudinal friction force by the support structure. The realistic response can be estimated with nonlinear characteristics of piping. In this study, the seismic evaluation method was investigated by the response spectra with the friction force. The friction force was replaced with the equivalent damping ratio calculated by the linear response analysis. The acceleration response spectra with the equivalent damping ratio were compared with the spectra which was calculated by the time history response analysis using the frictional force. As a result, the acceleration response spectra with the equivalent damping were larger about 1.5 times than the spectra using the frictional force. In the future, we will compare the stress calculated by the acceleration response spectra with the stress calculated using time history analysis considering friction force by support structures.