Inquiry Into Characteristic of Multiple Friction Pendulum System With Multiple Sliding Surfaces Under Bidirectional Loadings

In order to investigate the bidirectional characteristic of a multiple friction pendulum system (MFPS) with multiple sliding surfaces, a series of component tests were performed by using the shaking table in the National Center for Research on Earthquake Engineering, Taipei, Taiwan. The multiple friction pendulum system with multiple sliding surfaces consists of double concave surfaces, more than one intermediate sliding plates and one articulated slider located between the concave surfaces and intermediate sliding plates. These devices can continuously change their horizontal stiffness, damping, and displacement capacities during ground shaking by virtue of the properties such as radii and friction coefficients of multiple sliding surfaces. In this study, both uni- and bidirectional component tests of a multiple friction pendulum system with three and four sliding surfaces were carried out to investigate its mechanical characteristic. Furthermore, results obtained from the shaking table tests of an isolated steel structure demonstrate that the MFPS isolation system with multiple sliding surfaces could properly change its stiffness and damping effect, and effectively reduce the excitation force during ground shaking.