Reliability Study of Non-Destructive Inspections of Resistance Spot Welds in the Automotive Industry

The main aim of the present research is to calculate the reliability of non-destructive tests (NDTs) and use its results for decreasing the number of DT’s bodies. To this end, five car bodies were randomly selected from the production line. Then, different types of tests including Ultrasonic test (UT), Chisel test (CT), and Peel test (PT) were performed on the critical groups of Resistance Spot Welding (RSWs). The experimental results were categorized based on the strength defects of RSW including good-weld (OK), stick -weld (ST), and undersize of nugget diameter (IM). Bernoulli probability approach was used to calculate the reliability of NDT methods. The results indicated that the reliability of various techniques of NDT which are used in the automotive industry is more than 94%. However, the ability of IM defect determination by UT is low.