温变工况下超定独立成分分析导波监测方法  

Guided wave monitoring method based on over-determined independent component analysisunder temperature variation conditions

作　　者：肖航[1] 肖黎[1] 屈文忠[1] XIAO Hang;XIAO Li;QU Wenzhong(Department of Engineering Mechanics,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学工程力学系,武汉430072

出　　处：《振动与冲击》2020年第15期133-141,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金(5197052200)。

摘　　要：基于超声导波的结构健康监测技术在实际工程应用中受到变化的环境工况条件的影响,由于独立成分分析方法对于处理时变工况条件下的大量监测导波信号存在局限性,以及对不同程度的损伤表征研究存在不足,提出一种基于超定独立成分分析的导波监测方法并改进了基于k均值聚类的损伤指标。以广泛存在的环境温度作为环境变量,通过主成分分析从大量导波信号组成的观测矩阵中确定独立分量个数,使用独立成分分析将处理后的导波信号分解为独立分量,能够有效地将损伤与环境工况的影响分离到不同的独立分量中。对长期经受环境温度变化的铝板进行了导波监测实验,结果表明该方法能够有效减少独立分量数目并从大量导波信号中排除环境温度的干扰识别出损伤,并且对处于温变条件下的完整和不同损伤程度的铝板进行了损伤识别实验,进一步研究了该方法在排除环境温度干扰的同时表征损伤程度的效果。Ultrasonic guided wave-based structural health monitoring techniqueis affected by varyingenvironment and operating conditions in practical engineering applications. Due tolimitations of theindependent component analysis method to process a large number of monitoring guided wavesand lacks of studying different levels of damage characterization, a guided wave monitoring method based on over-determined independent component analysis was proposedhere and damage indexes based onk-mean clusteringwere improved. Widely existing environment temperature was taken as an environmental variable. The principal component analysis(PCA) was used to analyze the observation matrix composed of a large number of guided wave signals, and determine the number of independent components. The independent component analysis(ICA) was used to decompose the processed guided wave signals into independent components. Effects of damage and environmental operational conditions were effectively separated into different independent components. Guided wave monitoring tests wereconductedfor aluminum plates subjected to long-term changes of environment temperature. Results showed that the proposed method can effectively reduce the number of independent components and eliminate interferences of environment temperature in a large number of guided signals to identify damages. Furthermore, Damage identification tests were conductedforintact aluminum plate and those with different damage levels under temperature variation conditions. The effect to characterize damage level of the proposed method was further studied, while environment temperature interferences were eliminated.

关 键 词：导波 损伤识别 压电主动传感 超定独立成分分析 温度变化 

分 类 号：TG115.28[金属学及工艺—物理冶金]