框架结构系统辨识的统计方法研究

STATISTIC METHOD FOR SYSTEM IDENTIFICATION oF freme strucure

提出了土木工程结构的系统辨识及其统计方法研究的定义,并基于结构的不同动力响应,运用不同的统计方法,进行了系统辨识的研究。对于3层框架结构的实测、数值计算的动力响应进行了初步的分析,计算了特定工况下加速度响应的概率密度及其分布,以及不同工况的模态方差,结果表明,结构直接动力响应的统计特征难以对结构参数进行显著辨识。运用统计过程控制理论,在95%置信水平下,对结构损伤进行了定性、定位以及初步定量的辨识。同时,基于主成分分析方法,分别基于结构的加速度响应、模态响应,对结构的不同损伤工况进行了辨识。

The statistic method for system identification in civil engineering is defined,and different identifications are performed based on different dynamic responses.The experimental and numerical data of a frame structure were investigated.The statistical features of the acceleration were inspected on the probability density;the modal shapes were also inspected on the standard deviation.It is concluded that characteristic features are not sufficient for the identification.The damage conditions were identified by the Statistical Process Control theory with a confidence level.Furthermore,the conditions were identified using the Principle Component Analysis method based on the acceleration and the modal data respectively.