ACCELERATED STRUCTURAL DAMAGE VISUALIZATION THROUGH MULTI-LEVEL NONCONTACT LASER ULTRASONIC SCANNING AND VISUALIZATION METHOD THEREOF

摘要

The present invention relates to a device to accelerate the damage diagnosis of the structure through multilevel non-contact laser scanning and a diagnosing method thereof. The device includes a pulse laser generating an ultrasonic wave by emitting a laser beam to a structure; an ultrasonic wave measurer measuring the ultrasonic wave, generated in the structure; a rotary mirror controlling the pulse laser and the ultrasonic wave measurer; a counterstroke extracting module analyzing signals, collected from a pair of a measurement point and generation point of the ultrasonic wave, and extracting a counterstroke ultrasonic element in order to estimate a damaged position of the structure; a correlation analyzing module collecting a bidirectional ultrasonic signal through a single path and analyzing a correlation in order to estimate the damaged position of the structure; and an image processing module extracting damage information by making an image of the data, measured in the ultrasonic wave measurer, and then automatically determining the information. According to the present invention, the device is capable of quickly and accurately diagnosing a large structure by estimating a sketchy damaged position through the counterstroke extracting module and the correlation analyzing module by scanning the structure at low density and then scanning the estimated damaged position at high density.