超声Lamb波监测铝合金结构疲劳裂纹扩展实验研究  

Experimental Study on Monitoring of Fatigue Crack Growth for Aluminum Alloy Structure with Ultrasonic Lamb Waves

作　　者：王壮杰 严刚[1] 郭树祥[1] 汤剑飞[1] WANG Zhuangjie;YAN Gang;GUO Shuxiang;TANG Jianfei(State Key Laboratory of Mechanics and Control of Mechanical Structures,College of Aerospace Engineering,NanjingUniversity of Aeronautics&Astronautics,Nanjing 210016,China)

机构地区：[1]南京航空航天大学航空学院机械结构力学及控制国家重点实验室,南京210016

出　　处：《机械科学与技术》2023年第8期1366-1372,共7页Mechanical Science and Technology for Aerospace Engineering

基　　金：国家自然科学基金项目(11602104);南京航空航天大学基本科研业务费项目(NS2021002)。

摘　　要：对应用超声Lamb波在线监测金属结构裂纹在疲劳载荷作用下的扩展进行了实验研究。制备了含中心裂纹的铝合金平板结构试件,并在试件表面布设了压电晶片传感网络。疲劳实验中,在观测裂纹扩展的同时,采用压电晶片分别进行Lamb波信号的激励和接收,监测驱动器与传感器间的疲劳裂纹扩展行为。通过时域信号处理提取了Lamb波信号峰值点的幅值(AMP)与传播时间(ToF)特征,由柯西隶属度函数定义了改进的信号健康度指标及相应的损伤指标,并评估了健康度指标和损伤指标随裂纹扩展的变化趋势。最后,结合损伤概率成像方法,融合Lamb波激励-接收路径的所有损伤指标,近似表征了裂纹长度的变化,验证了该方法的可行性和有效性。This paper presents an experimental study on on-line monitoring of crack growth in metal structures under fatigue loading by using ultrasonic Lamb waves.An aluminum alloy plate structure with a central crack is manufactured and a network of piezoelectric wafers are mounted on the surface of the plate.During the process of fatigue test,piezoelectric wafers are used to excite and receive Lamb wave signals to monitor the fatigue crack growth behavior between the actuators and the sensors,meanwhile,the crack length is observed in real-time.With time domain signal processing,the features of amplitude(AMP)and time of flight(ToF)features at the peak points of Lamb wave signals are extracted.An improved degree of health index and correspond-ing damage index are defined through Cauchy membership function,and their variations with the crack growth are evaluated.Finally,the DIs in all excitation-receive paths are fused by the damage presence probability imaging method to approximately characterize the variations of crack lengths,proving that the algorithm proposed in this paper is feasible and effective.

关 键 词：裂纹扩展监测 超声Lamb波 健康度指标 损伤指标 损伤存在概率成像 

分 类 号：V214.4[航空宇航科学与技术—航空宇航推进理论与工程]