Topology optimization is a kind of conceptual design. The optimization results are shown in the figure, which can not be directly used as the final design results, but provide guidance and basis for further design. After repeated adjustment and optimization, the 3D model of the redesigned rocker box is shown in figure (b).
It can be seen from the section of the figure that the area of the four corners of the rectangular section increases, the width of the four sides decreases, and the stiffeners are arranged around the bearing hole. Because the stress level of the box at the roller end is low, the thickness of the box at the roller end is reduced.
Finally, a triangle supporting structure is added at the root of the rocker arm. The first six natural frequencies of the rocker box before and after optimization are compared. After structural optimization, most of the natural frequencies listed (except the 5th order) are increased significantly.