多层冷弯薄壁型钢结构住宅的地震响应分析

Seismic Dynamic Response Analysis for Cold-formed Steel Framing System of Mid-rise Residential Building

采用结构有限元分析软件ANSYS,建立空间模型对多层冷弯薄壁型钢结构住宅进行非线性时程分析。首先对2层冷弯薄壁型钢结构住宅进行模态分析,并与低层冷弯薄壁型钢结构住宅的实测周期、振型比较,二者吻合较好,验证了本文有限元模型的正确性。接着分析3层～6层冷弯薄壁型钢结构住宅在不同地面加速度峰值下的结构响应,结果表明:结构的位移和加速度均随输入地震波加速度峰值的增大而增加,各时程曲线逐渐由密变疏,表明结构周期略有增加。最后参考《建筑抗震设计规范》(GB 50011-2010)的相关规定,提出多层冷弯薄壁型钢结构住宅在多遇地震作用下的弹性层间位移角限值为1/750;在罕遇地震作用下的弹塑性层间位移角限值为1/100。

In order to analyze the nonlinear dynamic time-history response of cold-formed steel framing system of mid-rise residential building,a 3D finite element model is formulated with ANSYS structural analysis software.Firstly,modal analysis is done for a two-story building model.The predicted period and modal shape have a good correspondence with the actual response of 2-story building,which proved the finite element model is proper.Then,the structural response of 3~6 story-building is analyzed under different acceleration amplitudes by this finite element model.It demonstrates that when the amplitude of seismic-wave acceleration increases,the structural displacement and acceleration increase,but the waveforms of displacement and acceleration are similar.It also shows that the structural displacement-time and acceleration-time curves become sparse from dense with the increasing of amplitude of seismic-wave acceleration.Finally,refering to the relevant proposals of Code for Seismic Design of Buildings GB50011-2010,it is proposed that for cold-formed steel framing system of mid-rise residential building,the elastic ultimate story-drift is 1/750 under frequently occurred earthquakes,and 1/100 under severe earthquakes.