Monitoring fatigue crack growth using nonlinear ultrasonic phased array imaging
Monitoring fatigue crack growth using nonlinear ultrasonic phased array imaging
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DOI：
10.1088/1361-665x/aa6787
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发表时间：
2017-05-01
影响因子：
4.1
通讯作者：
Drinkwater, Bruce W.
中科院分区：
文献类型：
--
作者：
Cheng, Jingwei;Potter, Jack N.;Drinkwater, Bruce W.
最近出现的非线性成像技术有可能检测材料的降解和具有挑战性的缺陷，如闭合裂纹。本文对非线性超声成像(NUI)监测疲劳裂纹扩展早期阶段的性能进行了研究。将该技术与常规阵列成像技术相结合，应用于高周疲劳载荷作用下的钢质紧凑型拉伸试件的周期性监测。研究了这些技术的检测下限。借助显微照相术，进一步量化了它们定位和检测小裂缝的能力。结果表明，与传统的超声成像相比，NUI对失效早期发生的微尺度变化更敏感，即疲劳寿命约15%的可探测性开始。除了早期检测之外，NUI还具有提供疲劳裂纹的精确尺寸和监控裂纹扩展的潜力。
Nonlinear imaging techniques have recently emerged which have the potential to detect material degradation and challenging defects, such as closed cracks. This paper describes an investigation into the performance of nonlinear ultrasonic imaging (NUI) for the monitoring of the early stages of fatigue crack growth. This technique, in conjunction with conventional array imaging, is applied to the periodic monitoring of steel compact tension specimens subjected to high cycle fatigue loading. The detection limits of these techniques are investigated. Their abilities to localise and detect small cracks are further quantified with the aid of micrography. The results suggest that NUI is more sensitive than conventional ultrasonic imaging to the microscale changes occurring at the early stages of failure, i.e. detectability starts c. 15% of fatigue life. In addition to early detection, the potential for NUI to deliver accurate sizing of fatigue cracks and monitor crack propagation is also presented.