Simplified estimation method for first excursion probability of secondary system with gap Original Research Article

A simplified estimation method for the first excursion probability of the secondary system with gap such as pipings, tanks and other mechanical equipment having mechanical supports and joints installed on the primary system such as buildings is proposed. First, an analytical method for the secondary system with gap is presented. This method is based on the equivalent linearization method. As input excitations, artificial time histories are used. Next, using the proposed method, some numerical examples are shown. It is found that when the tolerance level is normalized by the maximum standard deviation of response of the linear secondary system, the first excursion probability is independent of mass ratio of the secondary system to the primary system, the damping ratio and the natural period of the secondary system.