Optimization of the Aluminum Riveting Process Using an Experimental Design Technique

Abstract

The purpose of this research is to determine the optimal factors existing in the aluminum riveting process. First, a 25 full-factorial design was used to screen five factors and two levels by selecting a lapping-joint method using only one rivet which exhibited significant riveting shear. The five riveting parameters used were press force 5,000 and 8,000 newtons, a thickness of material of 2.5 and 4mm, a size of hole of 4.7 and 5.2 mm, over long rivets of 4.7 and 5.2 mm and press times of 5 and 15 seconds. There were three parameter levels: thickness of the metal (2.5, 3.2 and 4.0 mm), size of the hole (2.5, 3.2 and 4.0 mm) and size of the over-long rivet (4.5, 5.6 and 6.7mm), then a Box-Behnken design was used in order to analyze the data and find the optimization point. The experiment found that a standard rivet has a shear strength resistance of 1,113.30 newtons. The study methodology was to prepare the riveting specimens use by selecting a lapping joint per one rivet to test the mechanical quality and shear. The results of the experiment show that the optimal conditions (to a statistically significant degree) were to use a 5.2 mm hole, a 2.8 mm level of thickness and a 6.3 mm over-long rivet. The optimal point for the shear test was 1,417.55 newtons, and an over-shear strength of 303 newtons could be increased by 27.32 percent.