Study on the shear failure mechanism of vulcanized rubber-metal bonding interface based on cohesive zone model

Rubber-metal bonding interface prone to adhesive failure. Cohesive zone model (CZM) is widely used in numerical simulation analysis of fracture of interfacial mechanics. In this paper, the traction-separation curve of the bonding surface of vulcanized rubber-metal specimen was obtained by tensile shear test and dumbbell rubber uniaxial tensile test. Then, the influence of shear strain of rubber itself was removed by numerical simulation of tensile shear of rubber, so as to identify the CZM parameters of rubber-metal interface.On this basis, a numerical model of the cohesive force of vulcanized rubber-metal was established, and the stress distribution, variation and damage evolution of the interface along the shear direction were analyzed microscopically. The initiation and propagation of cracks are explained and compared with the failure process and phenomenon of the test interface. The traction-displacement relationship curve was analyzed macroscopically, which was consistent with the traction-displacement relationship curve obtained by the experiment, and the error is less than 5 %. The CZM could accurately express the interface mechanical relationship of the experimental specimen. In addition, the influence of the width and length of the bonding interface on the mechanical properties of the bonding is also analyzed. With the increase of the width or length of the bonding interface, the maximum traction force increases linearly, but the relative displacement value of the initial bonding failure remains unchanged, and the length of the bonding interface has a more significant effect on the maximum traction force. The results show that the cohesive zone model can accurately and effectively analyze the shear failure of the vulcanized rubber-metal bonding surface, which provides a reference for the study of the failure of the bonding surface of other elastic composites.