NUMERICAL AND EXPERIMENTAL EVALUATIONS OF BASE-ISOLATED STRUCTURE CONSIDERING BEARING ISOLATION BEHAVIORS BASED ON MULTISCALE MODEL

Base-isolated techniques have been widely adopted in practical projects due to efficient isolation effects. The existing structural analysis methods of isolated structures principally utilize the macroscale model (spring element) to investigate the seismic behavior of isolated structure, which generally employs spring element to simulate isolation bearing. It can capture the overall response of isolated structures, but fails to consider the detailed characters of bearing isolation and other key components. In order to incorporate the mechanical properties of key components (such as isolation bearing), a multiscale finite element (FE) simulation method of isolated structure considering bearing isolation behaviors was proposed. Firstly, the multiscale interfacial connection equation between macroelement (beam element) and microelement (solid element) was formulated. Secondly, four series isolation systems (SIS) were formulated through the effective combination of the distinctive elements with different scales, including spring-beam model, spring-solid model, multiscale model (beam-solid model) and full-solid model (solid-solid model). The analyses of the aforementioned models simulated in Ansys, as well as testing results, were comparatively performed on the beam top under reversal loading. It illustrates that the multiscale simulation methodology can reflect the mechanical properties of key components (isolation bearing) and enhance computational efficiencies. The multiscale approach was further confirmed through a comparison with shaking table test results of SIS. Finally, the seismic behavior of base-isolated structure based on multiscale model was analyzed by the multiscale FEA method.