双向恢复力模型对基础隔震建筑风振响应的影响

Influence of biaxial restoring force models on wind vibration response of base-isolated buildings

为明确MSS、Casciati和Harvey and Gavin这3种常用双向恢复力模型计算基础隔震建筑风振响应的差异,采用3种模型模拟铅芯橡胶支座在水平单向和双向位移下的恢复力,对比试验或有限元结果的差异,采用3种模型对一算例在双向风荷载下隔震层位移、顶点位移和顶点加速度3个指标的差异进行了分析。研究表明:3种模型模拟铅芯橡胶支座在单向循环位移、方形和偏置方形位移下恢复力的趋势基本一致;而模拟圆形和偏置圆形位移时,MSS模型双向恢复力形状与有限元结果不同,不能较为准确地模拟支座双向耦合行为,Casciati模型误差稍小于Harvey and Gavin模型。Casciati模型和Harvey and Gavin模型计算风振响应基本一致;对于横风向响应均方根,3种模型差距不大;对于顺风向隔震层位移、顶点位移和顶点加速度均方根,MSS模型稍小,而对于顺、横风向隔震层位移峰值因子,MSS模型稍大;对于顺、横风向顶点加速度峰值因子和双向与单向模型顶点加速度最值比值随风速变化规律,MSS模型与其他模型差异较大。基于双向耦合效应模拟及风振响应指标的差异,建议采用Casciati模型考虑双向恢复力模型对基础隔震建筑风振响应的影响。

In order to clarify the differences of wind vibration response of base-isolated buildings calculated by three commonly used biaxial restoring force models of MSS,Casciati and Harvey and Gavin,three models were used to simulate the restoring force of lead-rubber bearing under horizontal uniaxial and biaxial displacement.Comparing the differences of tests or finite element results.The differences in base displacement,top displacement and top acceleration for a numerical example were analyzed using three models.The results show the trends that the restoring forces of three models simulate the lead-rubber bearing in uniaxial cyclic displacement,square and offset square displacement are basically the same.While simulating circular and offset circular displacements,the biaxial restoring force shape of MSS model is different from the finite element results,which cannot simulate the coupling behavior of the bearing accurately,and the error of Casciati model is slightly smaller than that of Harvey and Gavin model.The Casciati model and the Harvey and Gavin model are basically the same in calculating the wind vibration response.For the root-mean-square of the cross-wind response,the differences between the three models are not significant.For the root-mean-square of the along-wind base displacement,top displacement and top acceleration,the MSS model is slightly smaller,while for the peak factors of base displacement in along-wind and cross-wind,the MSS model is slightly larger.For the variation of the peak factor of top acceleration and the ratio of the maximum top acceleration of bidirection to unidirection with wind speed in along-wind and cross-wind,the MSS model differs from others.With the consideration of the simulation of biaxial coupling effect and the difference of wind vibration response,the Casciati model is suggested to consider the influence of biaxial restoring force model on wind vibration response of baseisolated buildings.