Research On Seismic Performance Of Single-layer Spherical Reticulated Shell Based On SMA-spherical Sliding Bearing

Friction pendulum bearing(FPB),as a traditional spherical sliding bearing(SSB),is a self-resetting isolation bearing with high bearing capacity and stability.However,the traditional FPB has the disadvantage of insufficient limit reset capability.Shape memory alloy(SMA),as a new type of intelligent material,has the characteristics of shape memory effect,super elasticity and high damping.It is widely used in engineering structures.Using SMA as an energy dissipation device can achieve a good reset effect.Aiming at the insufficiency of the traditional friction pendulum bearing's insufficient limiting capacity and the possibility of falling off when used for high-level vibration isolation,this paper proposed a vibration isolation device composed of SMA cable and FPB,and named it SMA-Spherical sliding bearing(SMA-SSB).The bearing consists of two parts: SMA cable and SSB,which dissipate energy synergistically,so that it has better adaptability under the action of multi-level earthquakes,so it has engineering application value.This article mainly carried out the following research work:(1)The SMA-SSB and corresponding FPB,Steel spring 1-spherical sliding bearing(SSP1-SSB)and Steel spring 2-spherical sliding bearing(SSP2-SSB)were designed.Based on the ABAQUS software,the finite element model of the bearing was established,and the numerical simulation was carried out.The hysteretic performance of the four bearings was compared and analyzed.The influence of design parameters such as different displacement amplitude,vertical pressure and friction coefficient on the mechanical properties of SMA-SSB was investigated.The results show that SMA-SSB can provide a fuller hysteresis curve under different conditions,which proves the rationality and possibility of using SMA cables to improve the shock absorption of ordinary spherical sliding bearings.(2)A single-layer spherical reticulated shell with a span of 50 m was designed to investigate its seismic response under different control methods.The results show that SMA-SSB has a good shock absorption effect on the single-layer spherical reticulated shell structure,and its limiting ability is better than FPB and SSP2-SSB.(3)A spherical reticulated shell model with different spans and different span-to-span ratios containing SMA-SSB was established by ABAQUS finite element software.It was analyzed under three-dimensional earthquakes,and the displacement response,acceleration response,equivalent plastic strain and displacement response of the seismic isolation device of the roof node and the lower supporting column in the controlled structure and the original uncontrolled structure were compared and analyzed.The research results show that:SMA-SSB has good isolation and energy dissipation effects on spherical lattice shell structures with different spans and different vector-span ratios.The existence of SMA makes SMA-SSB show more superior displacement control ability.(4)According to similarity theory,and a 1/10 scaled model of a high-position isolation reticulated shell for shaking table tests was designed.The shaking table test plan was proposed,and the numerical simulation of the scaled model based on the ABAQUS programwas performed,providing a reference for the subsequent shaking table tests.