New method for time-history analysis of seismic responses of a base-isolated structure

The broken line type of restoring force model of an isolation equipment with inter-storey shear type for a base-isolated structure is used to study its seismic elastoplastic responses. After comparing advantages and disadvantages of current various computing methods, a new method called dimensional increment and partitioning precise integration method (PIM) is proposed. With it, structural properties and external excitations can be considered separately and solving exponential matrices by PIM in each iteration step can be avoided. Typical numerical examples show that the proposed method is very effective to compute the seismic responses of the base-isolated structure, it not only increases the computing efficiency but also keeps higher computing accuracy.