The simulation of a double cantilever beam test using the virtual crack closure technique with the cohesive zone modelling

The fracture of an adhesively bonded joint is a complicated process of crack nucleation and propagation. In this work, a method for modelling the fracture process with separate nucleation and propagation phases is presented. The method combines the virtual crack closure technique (VCCT) with the cohesive zone modelling (CZM) on the finite element basis to take into account the development of fracture toughness. The method is applied to simulate a double cantilever beam (DCB) test as an example. Experiments using a butt joint specimen are carried out to support the adhesive characterization. The analysis focuses on the physical validity of the VCCT-CZM coupling and on the determination of applicable simulation parameter values. By using experimental data as a reference, the simulation results are compared to the results of traditional CZM and VCCT simulations. The comparison indicates that the applied combined CZM-VCCT method reproduces the DCB test cycles more accurately than the CZM and VCCT models.