Equal Load Carrying Capacity Design of Butt Joints Based on Plastic Limit Loads

Abstract

Abstract In order to reduce the weld size of weld joints designed based on equal load carrying capacity (ELCC) further, the shape of under-matching butt joints is designed with the parameter of plastic limit loads. The realization condition of ELCC is that the plastic limit loads of the weld equals to that of the base metal. Through analysing the tensile/bending load carrying capacity of weld zone, the weld shape was determined, and the method of tensile/bending ELCC design for butt joints is given. The ELCC joints are designed and their elastoplastic finite element analyses are carried out to verify their load carrying capacities. The tensile ELCC joint fractures at the base metal in the mode of overall yield fracture and its load carrying capacity reaches the tensile strength of the base metal. The load carrying capacity, deformability and stiffness of the bending ELCC joint are better than that of the base metal. The results indicate that the joints with acceptable size meet the requirements of ELCC, which is of great significance to the application of ELCC joints.