Semi-active control for isolated structure based on response evaluator of system respected to the source region and ground motion of earthquake

This paper presents a response evaluator which evaluates the response of the system and decides the control input to the system. The characteristics of the response evaluator is designed with the source region and ground motion of earthquake. It is applied to a base isolated structure with a semi-active oil damper whose damping coefficient has large or small values. The response evaluator is designed by the multi-layered neural network which consists of the building responses and the peak ground velocity as input data and switching signal for damping coefficient as output data. Some earthquake records are divided into 8 regions by the epicenter, and the representative record of each region is normalized to 3 levels of its peak velocity which is 25, 50 and 75 cm/s. The 8 response evaluators are designed for each earthquake region and the computer simulations are carried out. Absolute acceleration and relative displacement of each story are reduced when the response evaluator corresponding to the designed region is used, but the control performance is not so good used by the most of response evaluators designed at the other region. When the response evaluator is selected corresponding to the designed region and the appropriate criterion function is set, good control effect is obtained to the wide range of amplitude of earthquake.