基于时反导波检测的管道缺陷圆周定位研究
The analysis of crack locating in pipes using time-reversal guided waves
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摘要: 用传递函数的观点,分析由缺陷这个被动的导波源产生的时间反转波场的传播方式。通过推导时间反转波幅值的表达式,在理论上论证了时间反转聚焦效应可用于管道导波缺陷的检测和定位。在分析影响缺陷定位的重要因素的同时,阐述了基于时间反转理论的管道单缺陷和双缺陷定位试验研究,进一步说明了在管道导波检测时,采用试验与有限元结合的方式实现缺陷的轴向和周向定位的方法是实际可行的,该方法同时还解决了管道轴向位置相同的双缺陷辨识问题。Abstract: The temporal-spatial focusing effect of the time reversal method on the guided wave inspection in pipes is investigated theoretically with a transfer function. The amplitude of the time reversed wave propagating along the pipe is analyzed. The result demonstrated that the time reversal method can be used to enhance the inspection energy for the guided wave inspection in pipes and to locate the defects in circumferential direction. Based on that, a method to identify defects is described with experiment results. When the time reversed signals getting from the guided wave inspection experiment are applied on a numerical model, the defect can be recognized by the motion of the time reversed wave propagating along the pipe model.