쇼트피닝 잔류응력이 Leaf Spring의 피로강도에 미치는 영향

Spring is one of major suspension pan of vehicle. Thus, in the process of manufacturing, it is shot-peened to improve its fatigue strength. In this paper, residual stresses by shot peening were calculated through finite element analysis, and the effects of these residual stresses on fatigue strength of leaf spring were evaluated. Fatigue tests were performed with two kinds of specimens, one is actual leaf spring assembly, and another is 3-point bending specimen simply simulated. And all fatigue tests were also performed under the loading condition that was measured on the proving ground. From the results, the maximum load-fatigue life relation of leaf spring was defined, and test results have good agreement between 3 point bending specimen and leaf spring assembly. The effects of residual stresses by shot peening on fatigue strength of leaf spring is not large in the high load range, however, in the low load range, its effects were revealed a little.