Computational numerical models for seismic response of structures isolated by sliding systems

Abstract

The problem of sliding structures is discontinuous one as different sets of equations of motion with varying forcing functions are required for the sliding and non-sliding phases. This is inconvenient for the numerical integration of the governing equations for the response of sliding structures. To overcome such difficulties continuous hysteretic models of the sliding systems have been presented in the past. In the present study, a comparison of the response of structures (i.e. multi-storey buildings and bridges) isolated by sliding systems with conventional and hysteretic models of the frictional force of the sliding system is carried out to investigate the comparative performance and computational efficiency of the two models. The seismic response of isolated structures is obtained by solving the governing equations of motion using a step-by-step method under single and two horizontal components of real earthquake motions. For comparative study, the seismic response of a multi-storey building obtained by the conventional model is compared with the corresponding response by the hysteretic model under different sliding isolation systems, numbers of storeys and values of the fundamental time period of the superstructure. It is found that the conventional and hysteretic models of sliding systems predict a similar seismic response for isolated structures. However, the difference in the response between the two models is relatively more for the pure friction system as compared with the sliding systems with restoring force. Further, the conventional model is relatively more computationally efficient as compared with the hysteretic model. Copyright © 2004 John Wiley & Sons, Ltd.