BIW Resistance Spot Weld Parameter Standardization through Parameter Optimization across Various Sheet Metal Panel Combinations

Body in White (BIW) is one of the critical aggregates of an automobile. Establishing the quality parameters during body manufacturing is essential to achieve robust BIW structure. Spot weld integrity and dimensional accuracy are the two major quality parameters of a BIW. Weld integrity plays an important role in achieving dimensional accuracy and structural stability. Various combinations of sheet metals are joined together to form a BIW structure. Spot weld parameter selection is one of the critical activity and needs to be programmed for the various combinations of sheet metals. Weld parameter for the various combinations are calculated with the resistance of the joining sheet metals thicknesses. The calculated parameters are validated with the coupon test (or) peel test and it requires several iterations to establish weld integrity of the different combinations and the selected parameters get registered in the weld controller. The conventional process consumes a large quantity of weld coupons for destructive testing and weld parameters of every combination become unique. Maintaining the records of several unique weld parameter is a complicated activity and requires a high rate of control for re-programing during weld gun maintenance and other trials. This study addressed the issue in parameter selection for various combinations. Common material grades, thickness combinations, weld time and weld pulses were considered as major factors in the study. Standard parameters for the general combinations were identified through L27 Taguchi method and were validated with experimentation. Selection of standard parameters ensures a higher weld integrity and repeatability. Management of weld programs become easy with limited parameters.