The analysis of crack locating in pipes using time-reversal guided waves

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.