Effects of randomly distributed interface cohesive strength on the delamination of the REBCO tapes

•A 3D model considering the random distribution of interface strength is established.•The delamination performance of REBCO tape under transverse tensile was studied.•The parameters of Weibull distribution on delamination are investigated.•The stress profile of REBCO layer and the random damage of the elements are obtained. This paper investigates the effect of randomly distributed interface cohesive strength on the initiation and propagation of delamination of the REBCO tapes. A three-dimensional cohesive zone finite element model (FEM) is established with consideration of randomly distributed interface cohesive strength satisfied three-parameter Weibull distribution, which is used to analyze the influence of the randomness of interface cohesive strength on the delamination performance of tapes under transverse tensile. The simulation results show that the boundary for delamination beginning predicted by the model, considering the randomly distributed interface cohesive strength, has a random character and is closer to the actual situation. Furthermore, parameters that are important to the random Weibull distribution are also investigated. It is shown that the scale parameter and the minimum interface cohesive strength have negligible influence on the delamination strength. Meanwhile, it has a significant impact on the peak value of the stress at delamination initiation in the REBCO layer and its position. For a particular Weibull distribution, its median can be used as constant interface cohesive strength to simulate the macroscopic delamination behavior of the tapes, accurately and efficiently.