| 摘要 |
The process for non-destructive control of weld (6) produced by laser (3) on steel sheets (1, 2), comprises analyzing a resonant signal present in a frequency band of 90 Hz to 1 KHz captured by direct field hypercardioid microphones (4, 5) during welding, recording the captured signal, determining a frequency spectrum of the signal using Fourier transform, and determining the distribution of signal envelope. The microphone is placed below the weld that is opposite to a head of a laser weld. The resulting signals are classified to make a difference between standard or non-standard weld. The process for non-destructive control of weld (6) produced by laser (3) on steel sheets (1, 2), comprises analyzing a resonant signal present in a frequency band of 90 Hz to 1 KHz captured by direct field hypercardioid microphones (4, 5) during welding, recording the captured signal, determining a frequency spectrum of the signal using Fourier transform, and determining the distribution of signal envelope. The microphone is placed below the weld that is opposite to a head of a laser weld. The resulting signals are classified to make a difference between standard or non-standard weld. Static variables such as standard deviation, skewness, kurtosis, energy level and platitude of the distribution are applied on the signal envelope. The classified results are correlated with tensile tests carried out in a test tube produced with a part of weld. An independent claim is included for a device for non-destructive control of weld produced by laser on steel sheet. |
