Patent ID: 7946176

Claim:
A method for detecting the first arrival wave packet of an acoustic signal at a transducer of a structural health monitoring (SHM) system, the method comprising: selecting a path between a pair of transducers of an array of transducers attached to the structure, each transducer being operable to generate and apply an acoustic signal to the structure in response to the application of an electrical excitation signal thereto, and to detect an acoustic signal in the structure and to generate and output an electrical signal corresponding to the acoustic signal detected; transmitting an acoustic signal through the structure and along the selected path from a first one of the transducers; receiving the signal transmitted from the first transducer with the second transducer; removing electromagnetic cross-talk from the received signal; and, detecting the first arrival wave packet of the acoustic signal at the receiving transducer; wherein the removing of the electromagnetic cross-talk comprises: specifying an upper bound for a group velocity of an acoustic signal transmitted on the selected path between the first and second transducers; computing a lower bound of a time of transmission along the selected path by dividing the distance of the selected path by the specified upper bound of the group velocity; computing a gate time equal to the sum of the lower bound of the transmission time and a trigger time corresponding to the excitation of the signal at the first transducer; and retaining only the data in a signal waveform corresponding to times greater than the gate time.