Applicability of Proportional Damping for Seismic Response Evaluation Using Three-Dimensional Finite Element Method Model Consisting of Structures with Multiple Damping Properties

Abstract

The purpose of this study is to investigate the applicability of proportional damping to reduce the computational load, which is a common issue for seamless structural integrity evaluation with a 3D-FEM model. When the proportional damping is applied, it is necessary to compare this method with current design method (strain energy proportional damping) regarding on the seismic response calculation precision. Therefore, the research target is to construct a modeling method of proportional damping that realizes the same calculation precision as current design method. The ratios of the maximum stresses in strain energy proportional damping and proportional damping were confirmed using the 3D-FEM model with multiple damping properties, and the applicability of the proportional coefficients setting method based on the magnitude of the effective mass ratio was examined. As a result, it was confirmed that the proportional damping method can calculate the same stress distribution as current design method by setting the proportional coefficients for vibration modes with large effective mass ratios and for the upper limit frequency of the target frequency range.