To evaluate the seismic performance of base-isolated structures with rubber bearings at different temperatures,mechanical property tests were conducted to analyze the variation of mechanical parameters of rubber bearings with temperature.Finite element models of the base-isolated structures were established to analyze the influence of temperature-dependency of bearings on their seismic performance.The results indicate that:(1)As the temperature decreases from 20℃ to-25℃,the peak load of the hysteresis curve of LRB500 significantly increases;the post-yield stiffness,equivalent stiffness,yield load,and equivalent damping ratio increase by 21.1%,32%,42.7%,and 11.1%,respectively.For LNR500,the hysteresis curve changes less significantly,with an increase in equivalent stiffness by 19.0%.(2)Lower ambient temperatures lead to an increase in the total stiffness and total yield load of the isolation layer,resulting in a reduction in the damping efficiency of the base-isolated system.The base shear force,maximum interlayer displacement angle,and acceleration at the top of the superstructure all increase significantly.(3)Under low-temperature conditions,the maximum shear force,maximum displacement,maximum axial surface compression,and minimum surface compression of the isolation bearing undergo significant changes and may even reach limit states,jeopardizing the safety of the base-isolated system.(4)The influence of ambient temperature on the mechanical properties of rubber bearings and the seismic performance of base-isolated structures is very significant.Therefore,temperature effect analysis must be conducted during the design of base-isolated structures through experiments or finite element methods,combined with site meteorological conditions.
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