Finite element modeling of single-lap joint between GdBa2Cu3O7-x-coated conductors using cohesive elements

Abstract

Both the initiation of cracking and delamination growth have been observed in the joints between the GdBCO-coated conductors, which causes the degradation of electrical property irreversibly. In this paper, firstly, the tension (lap-shear) test of the single-lap joint is simulated to verify the selected material properties and the numerical model. Then, the delamination behavior of the single-lap joint between the GdBCO-coated conductors is investigated based on the cohesive model. The multiple layers of zero thickness cohesive elements are implemented within the tapes and interfaces between the tape and solder. Different boundary conditions are also considered to determine the corresponding delamination position and value of debonding load. With the classical beam theory and linear elastic fracture mechanics, the approximate analytical solution is given to throw light on the behavior of the joint. The numerical results show that the interface parameters such as cohesive strength can affect the positions of crack formation and stable extension of crack. In addition, the debonding load is influenced by the overlap length of the joint and constraint condition.