Design optimization of an automotive universal joint considering manufacturing cost

This paper presents the shape optimization of an automotive universal joint, by simultaneously considering manufacturing cost, maximum drivable joint angle and part volume. Comprised of three main components - two yokes and a cross trunnion - a universal joint is a linkage used to transmit rotational motion from one shaft to another when the axes are coplanar, but not coinciding. In this research, universal joint designs are analyzed and compared using a weighted sum of three objective functions: minimization of machining cost, maximization of adjoining shaft joint angle, and minimization of total part volume. Part modeling and analysis is conducted using the Finite Element Analysis package ANSYS and optimization is implemented using MATLAB. The results show Pareto frontiers for both the flange and weld yoke, constructed using the Adaptive Weighted Sum technique. These frontiers clearly illustrate the trade-off between machining cost and joint angle; that is, to increase the joint angle, a corresponding increase in the cost of the part is required. It has been shown that maximization of driveable joint angle requires a simultaneous increase in machining cost of 4.4% and 2.7% for the flange and weld yoke, respectively.