780MPa급 강재의 저항 점 용접 시뮬레이션 및 공정 변수 최적화에 대한 연구

Abstract

Nowadays, car manufacturers applied many high strength steels such AHSS or UHSS to car bodies for weight lightening. In this study, we conducted resistance spot welding simulation to optimized used. There two combinations for same steel sheet which were DP780 1.0t, DP780 1.4t. Dissimilar steel sheet combination with different thickness was 1.0t, and 1.4t of DP780. Different steel combinations were DP780 1.0t and SPRC440 1.0t, and DP780 1.0t and DP590 1.0t. Tensile shear strength estimated by using second order polynomial regression model and spatter estimated by using neural network. In addition optimized welding condition was determined in terms with weldability and productivity using objective function and fitness function.