Investigation of fatigue strength of pitman arm designed according to topology optimization

Fatigue damage occurs in metals as a result of being subjected to repetitive or fluctuating stress, which is much lower than their tensile strength. Fatigue is the most common cause of damage in mechanical structures. Therefore, most of the failures in the automotive industry are also fatigue-based. In this study, a critical part used in the steering subsystems of automotive vehicles, the pitman arm, is examined. Firstly, the loads to which the pitman arm is subjected were calculated, followed by the application of finite element analysis in a computer environment. During the study, the part's geometry was examined to identify less effective regions in load carrying. The geometry resulting from the optimization was designed to be suitable for production and subsequently manufactured. The optimized and non-optimized parts were then subjected to fatigue testing for comparison. As a result, approximately 11% weight reduction was achieved with topology optimization, and it was reported in the literature that material and energy savings could be achieved. It was observed that topology optimization had no significant effect on the part's fatigue strength, providing an advantage for both manufacturers and consumers.