A METHODOLOGY FOR CHARACTERIZATION OF WELD DEFECTS BY ULTRASONIC TESTING

摘要

The invention relates to a method for identifying weld defects by classifying reflected signals in an ultrasonic testing system, comprising the steps of providing an ultrasonic testing (UT) equipment (5) having an ultrasonic probe (3), the probe (3) is enabled to generate, receive and convert sound signals into electrical signals, the U. T. equipment (5) is capable of receiving electrical signals from the probe (3) and amplifying and displaying the received electrical signals, injecting ultrasound wave signals via the probe (3) at a predetermined location of a weld (2) in a job (1), the sound signals when encountering a defect in the weld (2) get reflected, the intensity of the reflection of the sound waves depending on the orientation of the encountered defect in the weld (2), receiving the reflected sound signals (7) in the probe (3) when the defect in the weld is so oriented that the reflected signals are capable of reaching the probe, converting the received sound signals (7) in the probe (3) to electrical signals and feeding the converted electrical signals (6) into the UT - equipment (5) in which the electrical signals (6) being amplified and displayed, feeding the electrical signals into a computer apparatus (8) embedded with a software for carrying out wavelet analysis of the received signals, detecting the plurality of features responsible for said reflection intensity of the sound waves from the weld defect, depending on the parameters of wavelet transformation produced through the wavelet analysis, and extracting the more important features out of said plurality of detected features for identifying the nature of the weld defects.