疲劳裂纹扩展的非线性超声相控阵成像定位检测  

Nonlinear Ultrasonic Phased Array Imaging for Fatigue Crack Propagation Location Detection

作　　者：滕达 刘志勇 刘立帅 项延训[1] 轩福贞[1] TENG Da;LIU Zhiyong;LIU Lishuai;XIANG Yanxun;XUAN Fuzhen(School of Mechanical and Power Engineering,East China University of Science and Technology,Shanghai 200237)

机构地区：[1]华东理工大学机械与动力工程学院,上海200237

出　　处：《机械工程学报》2024年第24期25-34,共10页Journal of Mechanical Engineering

基　　金：国家重点研发(2022YFF0605600);国家自然科学基金(12025403,U1930202,12104155)资助项目。

摘　　要：发展一种用于监测疲劳裂纹扩展的非线性超声相控阵成像方法。通过物理聚焦和虚拟聚焦两种相控阵聚焦模式实现一种等效的入射波幅值调制,以基频能量损耗比来间接分析非线性谐波生成量,在常规相控阵硬件条件下实现闭合疲劳裂纹尖端定位,并进行了二次谐波扫查验证。进一步将该方法应用于疲劳裂纹扩展过程监测,在显微测量的辅助下探究其量化裂纹尺寸、检测早期损伤和监测疲劳寿命的能力。结果显示,与常规线性超声相控阵相比,非线性超声相控阵成像能够更有效地对疲劳裂纹闭合部分进行检测;该方法对早期损伤比较敏感,约从疲劳寿命的16%开始可实现有效检测,并精确量化疲劳裂纹尺寸和监测裂纹扩展情况,使其在服役结构的寿命研究和突发事故预防方面具有较好的发展前景。A nonlinear ultrasonic phased array imaging method is developed for fatigue crack growth monitoring.An equivalent amplitude modulation of incident wave is realized through two phased array focusing modes of physical focusing and virtual focusing.The nonlinear harmonic generation is analyzed indirectly by using the fundamental frequency energy loss ratio.The nonlinear imaging detection of closed fatigue crack under conventional phased array hardware conditions is realized,and verified by second harmonic scanning.This method was further applied to the monitoring of fatigue crack growth process,and its ability of quantifying crack size,detecting early damage and monitoring fatigue life was investigated with the aid of micro measurement.The results show that compared with conventional linear ultrasonic phased array,nonlinear ultrasonic phased array imaging detect the closed part of fatigue crack more effectively.The method is sensitive to early damage,and effective detection can be achieved from about 16%of the fatigue life,and the fatigue crack size can be accurately quantified and the crack propagation can be monitored.This method has a good development prospect in service structure life research and emergency prevention.

关 键 词：超声相控阵 非线性成像 疲劳裂纹 监测 

分 类 号：TG156[金属学及工艺—热处理]