Pareto optimal solution set strategy based on multiobjective optimization for the clinching tools

Abstract

The geometric size of the clinching tools determines the geometric size and strength of the clinched joint. This study establishes an orthogonal analysis experimental plan to examine how a group of geometric size of the tool affects the objective functions of a clinched joint, including its bottom thickness, necking thickness and interlocking thickness. Particularly, the study evaluates the effects of die radius, die depth, punch stroke, punch radius and punch fillet on the geometric size of the clinched joint. A multiple quadratic regression model is used to quantitatively analyze the contribution value of the feature parameters of the tool to the objective function. Furthermore, a multi-objective genetic algorithm based on the Pareto solution is used to solve the multiple quadratic regression model, and the optimal combination size of the tool is determined by comparing theoretical and simulation calculations. The optimal die radius is 4.6 mm, the die height is 1.10 mm, the punch stroke is 4.1 mm, the punch is 2.6 mm and the punch filled is 0.5mm. These parameters are used to manufacture a pair of tool for improving the clinched joint quality.