The coiled tubing fatigue belongs to overlow cycle fatigue at multi-axial stress state.The prediction theory of this field is far from comp lete. 而连续油管的疲劳是应力状态较复杂的多轴超低循环疲劳，目前该疲劳寿命预测理论还很不成熟。
Based on the ultrasonic guided wave technique and the dispersive waveform prediction method, a method about how to image defects in pipes is presented. 摘要在导波传播理论和频散波形预测理论的基础上，研究了超声导波在检测管道时，如何利用时域波形重构缺陷图像的问题。
