STFT变换在高层框架结构地震损伤程度识别中的应用

摘要

为了研究地震作用下高层框架结构的损伤程度信息,以结构刚度折减率为损伤程度指标,以结构的频率变化率为损伤程度识别参数,采用Matlab模拟结构在不同的损伤程度指标下的加速度响应数据,利用短时傅里叶变换方法对响应数据分析得到结构的模态参数,从而建立损伤程度指标与结构模态参数的函数关系.将损伤结构的模态参数代入函数关系式计算结构的损伤程度指标.采用同济大学振动台试验数据,利用此方法识别结构的损伤程度与振动台试验观察到的损伤程度高度吻合.%In order to detect the damage degree,the discount of stiffness is regarded as the damage degree index and the frequency change rate is regarded as the parameter of the damage degree detection.The short time Fourier transform is used to extract the rate of frequency change of acceleration response which is from the model of matlab,then the function between the index of damage degree and the rate of frequency change is established.Thus the damage degree would be detected according to the rate of frequency change of the damaged structure.The data of shaking table test which from Tongji University has demonstrated its accuracy and availability.The result shows that the damage degree is very similar between the damage degree detection and the actual damage degree.