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A Study of Resistance Spot Welding Manufacturability Using Design of Experiments
Published September 26, 1994 by Automotive Technology Group, Inc. in United States
A statistical design of experiments technique has been used to characterize the effects of a number of factors related to the resistance spot welding process. The factors examined include: (1) the presence or absence of a material coating (zinc), (2) variation in flange length, (3) electrode position relative to the edge of the component, (4) electrode face diameter, (5) angular alignment between the computer and the electrodes, (6) axial alignment between the electrodes, and (7) weld shape. Welds were evaluated using mechanical testing methods and average button diameter measurements. The test methods included tensile shear, tensile fatigue, and tensile peel tests. Results showed that the presence of a material coating allowed for larger weld nuggets to be formed which was beneficial in each type of mechanical test. Decreasing the flange length was found to decrease tensile peel strength and reduce fatigue life. The presence of edge welds reduced tensile shear and tensile peel strength. An increase in electrode face diameter was found to be detrimental in each type of mechanical test. Variation in angular alignment or variation in axial alignment were found to adversely affect the tensile fatigue and tensile peel properties of spot welded coupons. The presence of the irregularly shaped weld was found to decrease tensile shear strength and reduce the tensile fatigue life.