Application of a programmable multi-channel ultrasonic system for in-line quality monitoring of spot welds

This paper presents the use of a multi-channel ultrasonic system for real-time quality monitoring of resistance spot welds. Currently, in-line systems use a single element transducer installed inside the welding electrode which capture the entire welding process. The single element transducer can very accurately determine the quality of a spot weld by acquiring A-scans in the center of the heat affected zone during welding. The multi-channel ultrasonic quality monitoring setup being presented contains 52 elements driven by the Ultrasound Advanced Open Platform (ULA-OP). By having 52 elements available, we are able to acquire A-scans in several areas of the heat affected zone simultaneously to monitor the quality at these areas. The setup presented provides a method for improving in-line, nondestructive evaluation of spot welds.