차체구조물에서 면내굽힘모우멘트 및 과하중이 피로특성과 균열전파 거종에 미치는 영향에 관한 연구

Actually, a driving cars are subjected to random loads with variable amplitude in the road. Although it is necessary test method considering random loads with variable amplitude, nearly all tests have been performed under constant load conditions in the laboratory. In this study, the overload factor affecting on the fatigue strength, crack initiation and propagation directions of spot-welded specimens have been studied. Because it is important to analyse and predict crack initiation position and propagation directions on the spot weld area for strength design of automobile body structure.