研究発表

スライディングモード制御はパラメータ変動やモデルの不確かさに対して優れたロバスト性を持つ。しかし、複数の制御パラメータを要し、それらの設計法は確立されていない。本研究では、これらの制御パラメータを建物の供用期間における被害発生確率を最小化するよう決定する設計手順を提案する。セミアクティブ免震建物を対象に検討を行い、提案手法に基づきパラメータを決定した場合の被害確率と、従来の手順による一定の強さの設計用地震動に対する応答を最小化するようパラメータを決めた場合の被害確率を比較し、その差を明らかにする。

Many researchers have investigated the vibration characteristics of mid-story isolated buildings. However, a formula to estimate their maximum responses has still room for improvement. A complex complete quadratic combination method is reformed using mode-dependent peak factors. The response of a mid-story isolated building model under white noise ground motion is analyzed and it is confirmed that the reformed formula gives slightly larger, safer-side estimates in most cases.

Finite element analysis is carried out for simultaneously investigating global displacement and local stress responses of laminated rubber bearings under earthquake excitation. Natural rubber bearings are attached at the base of a building frame. The frame members as well as the rubber bearings are discretized into hexahedral finite elements with more than 3 million degrees of freedom. It is shown that the incompressible and hardening properties of natural rubber can be accurately simulated, and the non-uniform deformation and stress distribution of rubber bearings under static and dynamic loads are successfully evaluated through a finite element analysis.