| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for detecting a micro cold crimping defect by an ultrasonic wave, and a device used therefor. SOLUTION: An ultrasonic wave is allowed to enter a joint surface, to thereby detect the micro cold crimping defect from a waveform strain of a transmitted wave to an incident wave. When the ultrasonic wave is a longitudinal wave, the ultrasonic wave is allowed to enter the joint surface in a plurality of times with changed amplitudes so that each amplitude becomes vertical to the joint surface, and the amplitude ratio between a fundamental wave and a higher harmonic is determined by performing frequency analysis of the waveform of the transmitted wave to the incident wave for each incidence, and existence of the micro-cold lapping defect is determined by comparing each amplitude ratio acquired relative to each incidence. In the case of a transverse wave, the ultrasonic wave is allowed to enter the joint surface in a plurality of times with changed frequencies so that the amplitude becomes parallel to the joint surface, and the amplitude ratio between the fundamental wave and the higher harmonic is determined by performing frequency analysis of the waveform of the transmitted wave to the incident wave for each incidence, and existence of the micro cold crimping defect is determined by comparing each amplitude ratio acquired for each incidence. COPYRIGHT: (C)2005,JPO&NCIPI
|
