SRC异形柱框架地震损伤识别研究

Seismic Damage Identification for SRC Frame with Special-Shaped Columns

基于型钢混凝土(SRC)异形柱空间框架的振动台试验,获取其加速度响应信号、位移响应信号、应变响应信号,分析其破坏过程。研究结果表明,随着加速度峰值的增大,模型表面裂缝充分发展,梁端纵筋及一层柱脚型钢相继进入屈服状态;SRC异形柱框架的破坏模式呈典型的梁铰破坏机制。采用MATLAB对结构频响函数进行分析,得出结构的一阶和二阶自振频率分别为7.3 Hz和8.0 Hz。基于结构内部损伤与结构频响函数的对应关系,通过对模型结构频响函数产生的变化进行分析,可知结构内部损伤不断发展,自振频率不断降低。基于不同白噪声工况下结构频响函数的变化,对SRC异形柱空间框架在地震作用下的损伤程度进行评估,结果表明,该方法可较好地反映结构在遭遇地震作用时的损伤发展程度。

shaped columns,the acceleration response,displacement response,and strain response was obtained in the test.The failure process was analyzed.Results show that with the increase of the peak ground acceleration(PGA),the cracks develop fully on the surface,longitudinal bar and shape steel enter the yield state in order;the failure modes of SRC special-shaped column frame is a typical beam hinge failure mechanism.Based on the experiment,the structure frequency response function(FRF)was analyzed by MATLAB.It indicates that the natural frequencies for the 1st and 2nd modes are 7.3 Hz and 8.0 Hz,respectively.By analyzing the change in structure frequency response function,it indicates that the structure internal damage will aggravate and the natural frequency will decrease.Finally,based on the frequency response function of the structure under different white noise loading conditions,the seismic damage index was put forward for the SRC special-shaped columns frame,which can be better reflected the damage development of structure under earthquake.