以聚焦能量为导向管道导波小缺陷检测研究

为了实现导波的检测能量尽可能聚焦于缺陷处。通过研究时间反转聚焦理论,对时间反转法中导波幅值表达式进行了推导,给出了一种基于时间反转聚焦理论超声导波检测管道缺陷的方法。同时对含有不同尺寸的非穿透型裂纹缺陷的管道通过数值模拟的方法,进行了管道缺陷的轴向与周向定位,得到了时间反转法后反射回波系数是直接导波反射回波系数的3倍,由此证明了时间反转法的时-空聚焦的特性,即时间反转导波同时到达缺陷位置,实现了能量的汇聚。采用理论与仿真结合的方式,论证了时间反转聚焦理论可用于管道导波的缺陷检测,提高小缺陷的检出能力。

Research on Focusing Energy-Oriented Inspection for Defects in Pipes

In order to realize the guided wave energy to focus on the defects as soon as possible, a theory based on time reversal focusing of pipeline guided wave and simulation was studied and the amplitude of the time-reversed wave propagating along the pipe was analyzed. A method based on time reversal focusing theory of pipes ultrasonic guided wave defect detection was studied. Based on that, numerical simulation was carried out for steel pipe with different sizes of non through thickness defects, axial and circumferential location of the defective steel pipe were carried out after time reversal method was applied. The reflection coefficient is three times of the direct guided wave reflection coefficient, thus showing the temporal-spatial focusing effect of the time reversal method, that is, a time reversal guided wave can realize energy focusing on the defect. Theory and numerical simulation demonstrate that the time reversal method can be used to enhance inspection energy for the guided wave inspection in pipe. The time reversal guided wave method is more favorable for the small defect inspection in pipes.