Characterization and classification of spot welds by ultrasonic diagnostic techniques

A system for determining the quality of a spot weld in a workpiece, comprising:

• an ultrasonic probe comprising a two-dimensional array of ultrasonic sensors placed above a selected weld spot over a work surface;
• a display screen for displaying visual information related to ultrasound signal attenuation;
• and
• a computer configured to:
• receive from each sensor in the array a raw ultrasonic A-scan, wherein each A-scan includes a reflected ultrasonic wave from the single weld spot;
• identify intensity peaks, as function of distance, in each A-scan;
• analyze an intensity of each A-scan versus a distance inside the workpiece;
• for each A-scan detect if there are intermediate signals between the peaks;
• assign a color mark for each A-scan based on the analysis and the detection;
• generate a color map, comprising the color marks of each A-scan;
• count numbers of A-scans assigned with the same color mark, for all A-scans in the map;
• and
• determine a quality of the spot weld as a whole based on the numbers.