Dynamic characteristic analysis and shaking table test for a curved surface isolated structure

To reduce the displacement of an isolation layer, an innovative curved surface isolated structure (CSIS) system was put forward by using the curved surface characteristics of the isolation layer and the weight of the structure. Firstly, a simplified analysis model with multiple isolators considering the rotation of the upper structure around the center of curvature of the isolation layer and the oscillation around the center of the isolation layer was established. Subsequently, two CSIS models, with 4 degrees inclined isolators and 8 degrees inclined isolators, separately, were produced and a shaking table test was conducted. For comparison purpose, a normal isolated structure (NIS) model and a non-isolated structure (NS) model were also tested. The dynamic characteristics, acceleration and displacement responses of different models are compared and discussed. Finally, finite element models of the CSIS were established by using the software ABAQUS and the numerical simulation results were compared with the test results. The results show that the displacement responses of a CSIS are reduced and the CSIS can return to the initial position faster than the NIS; the acceleration response of a CSIS is slightly increased relative to the NIS, but significantly reduced compared to the NS; the acceleration time-history curves of each floor and the displacement time-history curves of the isolation layer for numerical simulation results show good agreement with experimental data.