Effect of Shot Peening on the Fatigue Strength of Automotive Tubular Stabilizer Bars DC 218

Abstract

This paper concerns issues related to the development of designs of stabilizer bars for new motor vehicle models. It involves not only the designing of a stabilizer bar with the shape required by the manufacturer, but also the preparation of bending and heat treatment processes as well as the performance of strength and fatigue tests. In the prototype development phase, the simulations techniques (FEM) may be used to assess the design. The article contains a detailed analysis of a stabilizer bar designated with the DC 218 VA symbol. Performed numerical strength and fatigue calculations showed that the developed stabilizer bar design with the desired shape did not achieve the required number of fatigue cycles. It was also proven at the test stand by testing a prototype stabilizer bar. Therefore, it was suggested to supplement the technological process with an additional shot peening operation whose main aim was to reduce the length of microcracks on the stabilizer bar’s surface. This effect was confirmed during comparative metallographic tests of not shot – peened and shot – peened stabilizer bars. After shot peening, the analysed stabilizer bar reached a fatigue strength which exceeded the limits set by the manufacturer.

Keywords

• Shot-peening
• Residual stresses
• Fatigue
• Finite Element Method