多层冷弯薄壁型钢住宅体系动力时程分析

Dynamic Time History Analysis for Mid-rise Cold-formed Thin-walled Steel Residential Building System

在采用有限元方法验证三层冷弯薄壁型钢房屋振动台试验结果的基础上,建立了多层冷弯薄壁型钢结构住宅空间整体模型,分析了模型前3阶自振频率、振型以及双向地震作用下的加速度、位移响应和水平地震剪力,考察了多层房屋的抗震性能。结果表明:《低层冷弯薄壁型钢房屋建筑技术规程》推荐的基频计算方法适用于多层冷弯薄壁型钢结构体系;随着输入地震波峰值加速度的增加,模型各层加速度幅值、相对位移和最大剪重比均增大,而各层峰值加速度放大系数有降低的趋势;随着结构高度的增加,模型各层峰值加速度放大系数、相对位移和最大剪重比均增大;多层冷弯薄壁型钢结构体系在多遇地震和罕遇地震作用下结构X向和Y向的水平地震剪力和最大层间位移角满足《建筑抗震设计规范》的要求,具备较好的抗震性能。

The spatial models of mid-rise cold-formed thin-walled steel residential building were established based on the shaking table test results of three-storey cold-formed thin-walled steel building verified by finite element method.In order to investigate seismic performance of mid-rise building,the first three natural frequencies and vibration modes as well as acceleration response,displacement response and horizontal seismic shear under bidirectional earthquake action were conducted on spatial finite element models.The results show that the fundamental frequency calculation method recommended in Technical Specification for Low-rise Cold-formed Thinwalled Steel Buildings is appropriate for mid-rise cold-formed thin-walled steel structural system.The acceleration amplitude,relative displacement and maximum shear-weight ratio of each floor raise with the increase of seismic-wave acceleration amplitude,while the peak acceleration amplification coefficient of each floor decreases.Moreover,the peak acceleration amplification coefficient,relative displacement and maximum shear-weight ratio of each floor raise with the increase of structural height.The horizontal seismic shear force and maximum storydrift ratio of mid-rise cold-formed thin-walled steel structural system in Xand Y direction underfrequently earthquake and rare earthquake are satisfied with the requirement of Code for Seismic Design of Buildings which demonstrating that this structural system has better seismic behavior.