基于混沌激励与吸引子分析的结合面损伤识别方法

工程结构在使用寿命周期内，各种环境因素会导致结合面出现损伤，从而威胁结构的完整性和功能性，甚至诱发安全事故。研究了一种利用混沌激励与吸引子几何特性进行结合面损伤识别的方法，采用混沌振动信号激励待测结构，对采集到的加速度响应信号进行相空间重构，并构造了一种基于吸引子局部方差计算的特征参量用于损伤识别，同时研究了影响特征参量的主要参数。设计了悬臂梁结合面损伤识别实验，控制固定端螺栓预紧力的下降来模拟结合面损伤，利用上述方法对结合面的损伤状态进行了识别。结果表明：本文方法能够识别结合面的损伤状态，所构造的特征参量随损伤程度改变单调变化，响应测点配置、特征参量计算参数等对损伤识别的效果有影响。

Joint damage identification using chaotic excitation and attractor analysis

In their operational lifetime,engineering structures suffer joint damage inevitably under environmental loads,it may affect integrity and functionality of structures,even causes catastrophic events.Here,a method using chaotic excitation and attractor geometric property analysis to identify joint damage was presented.A chaotic excitation signal was used to excite a structure,and the measured structural acceleration response was reconstructed in state space.A new feature based on attractor local variance was extracted and used to identify joint damage.The parameters influencing feature extraction were also analyzed.A test with a cantilevered beam for joint damage identification was designed and the joint damage conditions were quantified by varying the fastener preload.Five different joint damage conditions were identified.The results showed that the proposed approach works well in detecting joint damage,the feature varying is monotonic with increase in damage,and the location for measuring response and calculation parameters have influence on damage identification.