Simulation of distortion induced in assemblies by spot welding

Maintaining dimensional tolerances during the manufacture of vehicle bodies is important to the automotive sector. With the industry's drive towards continuous improvement there is increasing focus on the effect of the joining process on the final assembly. A simulation tool that can predict the distortion resulting from assembly offers potential time- and costsavings throughout design and manufacture. Although individual spot welds have been studied in detail, to-date methods to predict the distortion of a final assembly have concentrated on the variation of the constituent components. In the current paper simulation is used to predict the distortion of an assembly owing to spot welding using a local/global approach where the local distortion occurring around a single spot weld is projected onto a global assembly at each of the weld locations. The comparisons of the simulations of the assemblies with coordinate measuring machine (CMM) data under different clamping conditions suggest sufficient agreement with experimental data to be of value to engineers. A number of possible enhancements are suggested to improve the accuracy of final shape prediction