基于因子分析和序贯概率比检验的结构损伤识别

Structural damage identification based on factor analysis and sequential probability ratio test

提出一种基于因子分析和序贯概率比检验的结构损伤识别方法。基于健康监测数据提取的结构状态特征不仅受结构状态的影响,而且受环境因素、测量噪声、分析误差的影响。当影响结构状态特征的环境因素未知或者不能完全测量时,基于因子分析可以提取结构状态特征场的公共因子作为环境影响效应的映射,并结合序贯概率比检验识别结构损伤。首先对因子分析的基本理论进行介绍,并建立因子分析的矩阵扩展法,在此基础上讨论基于Mann-Whitney秩和的序贯概率比检验的结构状态判别。最后通过1个斜拉桥的数值算例验证方法的可行性,结果表明该方法能够准确地识别较小的结构损伤。

A novel method of structural damage identification based on factor analysis and sequential probability ratio test was proposed. The structural condition features, which were extracted from the monitoring data, were not only affected by structural condition, but also influenced by environmental factors, measurement noise and analysis errors. When the environmental factors which affected structural condition features were unknown or could not be measured, the common factors of structural condition features field, which were calculated by the factor analysis, could be used to express the influences of environmental factors, and structural damage could be identified based on the sequential probability ratio test. The factor analysis theory was introduced firstly and the matrix excluding method of the factor analysis was derived. And then the structural condition was identified correctly by the sequential probability ratio test based on Mann-Whitney rank sum test. Finally, a numerical example of a cable-stayed bridge was used to validate this method, and the results show that the method can correctly identify small structural damage.