Development of a monitoring method for fatigue damage using piezoelectric element

本文介绍了角焊缝附近穿透疲劳裂纹超声监测技术的发展。透射波和反射波相结合的测量被认为是有用的定量检测的疲劳裂纹。在发射探头和接收探头间距为100mm的情况下，我们的方法得到40mm作为定量检测的有效区域。另一方面，疲劳裂纹导致低估了低应力幅下的裂纹。因此，通过与船舶运动同步来优化数据采集的时序是重要的。

This paper describes a development of ultrasonic monitoring technique applied for through thickness fatigue cracks neighboring fillet weld parts. A combination of transmitted wave measurement and reflected wave measurement was found to be useful in quantitative detection of the fatigue crack. In case of 100mm separation between transmitting probe and receiving probe, our method obtains 40mm as an effective area for the quantitative detection. In other hand, fatigue crack bring about an underestimation of the cracks under lower stress amplitude. Therefore, it is important for a timing optimization of data acquisition by a synchronization with ship movement.