蜗卷弹簧缺陷的周向导波检测

以高压断路器开合闸机构的核心部件蜗卷弹簧为研究对象,通过数值计算得到其外圈周向导波频散曲线以及频率和入射角之间的关系,并以此为依据选择能激励特定导波模态的超声导波探头。对蜗卷弹簧在同个横截面、不同周向距离处预置两个轴向缺陷,利用选定模态的导波对该区域和非缺陷区域进行检测,通过端面回波时间和声程确定激励的导波模态,通过缺陷回波时间计算出缺陷和激励探头的距离,实现缺陷的定位。

Circumferential Guided Wave Detection for the Defects in a Coil Spring

In this paper, the coil spring of the core part of the operating mechanism in the high-voltage circuit breaker is taken as the research object. The dispersion curves and the relationship between frequency and incident angle of outer ring are obtained by numerical calculations. Based on the relationship, the ultrasonic guided wave probe for exciting specific guided mode is selected. The defect area containing two axial defects prefabricated at the different circumferential distance of the same cross section on the outer ring, as well as the defect-free area, are detected by the selected modes. The guided wave mode is determined by the end echo time and the acoustic distance. The distance between defect and excitation probe is calculated through defect echo time to locate defects.