An algorithm for the estimation of the quality of the spot welds

Аннотация

Spot welds are widely used in industry, especially in automotive, so welds must be reliable. One of the approaches to estimate the quality of the spot welds is to use ultrasonic testing. Spot welding is used in automotive repair industry as well. However spot weld testing device, dedicated for the automotive repair industry, is not available. The objective of this work was to develop an algorithm for estimation of the quality of the spot weld, to be used in a simple device in automotive repair industry. The algorithm developed identifies the peaks in the acquired signal and separates the main peaks (ultrasonic signal reflected from the backwall of the weld) from intermediate peaks (which identify the defects in the weld or undersized weld). Then, according to the peaks distribution and peak amplitude variations in the signal the quality of the weld is determined and automatic pass or fail indication given. The algorithm was verified using the finite element model of the good weld, undersized weld and a weld with a pore.