In-situ ultrasonic detection of resistance spot welding quality using embedded probe

摘要

The in-situ ultrasonic detection system is developed to evaluate the resistance spot welding (RSW) quality automatically. An embedded probe is used to obtain the ultrasonic testing signal of spot weld after the RSW process. It is built in the spot welding electrode. The signal eigenvalues such as acoustic pressure amplitude, distance of echoes, main frequency, main frequency amplitude, low-frequency component are obtained. The corresponding mathematic calculation models are established to realize the quantitative ultrasonic evaluation of RSW quality. A specialized evaluation software is developed to calculate the nugget sizes and classify the weld type automatically. Several verification tests are conducted and showed that the RSW quality can be rapidly and effectively evaluated by the in-situ ultrasonic detection system.