Theoretical and numerical investigation of mode-I delamination of composite double-cantilever beam with partially reinforced arms

In this paper, a theoretical analysis model and two simulation methods are applied to characterize the quasi-static and fatigue delamination of composite double-cantilever beam (DCB) with partially reinforced arms. The test data of partially reinforced DCB were used as benchmark to verify the analysis model and simulation, and cohesive zone models (CZMs) and virtual crack closure technique (VCCT) are used in simulation. It is shown that the partially reinforced DCB has a unique double-peak load–displacement relationship, rising and sudden release of R-curve near the reinforced area, and produces instability development. By comparing the results of simulation and experiment, the simulation based on the exponential CZM can calculate the delamination of partially reinforced DCB under both quasi-static and fatigue loading, while VCCT method will generate a straight delamination front edge under the reinforced area and underestimates the influence of the previous load on the later due to the lost of microdamage from previous loading.