Mode-I interlaminar fracture modeling of DCB composite laminate using finite element techniques

Interlaminar fracture is the most common type of failure in polymeric textile composites because these composites are prone to delaminate under the influence of external loading. Depending on the type of loading, the delamination in textile composites can be classified into Mode-I, Mode-II, Mode-III, and Mixed Mode-I/II interlaminar fracture. In this research work, Mode-I interlaminar fracture modeling of a double cantilever beam (DCB) composite laminate is performed on ABAQUS software as a cost-effective approach. The finite element-based fracture modeling techniques, virtual crack closure technique (VCCT), cohesive zone modeling (CZM), and extended finite element method (XFEM) were employed under the two-dimensional and three-dimensional interlayer crack propagation to evaluate several load-displacement responses. The top and bottom parts of the DCB specimen were bonded to each other by defining the bonded node set between their surfaces and the interaction properties given to these bonded nodes in the VCCT and CZM (Surface) techniques. A layer of cohesive element was provided between the top and bottom parts of the DCB specimen in the CZM (Element) approach to investigate the crack growth behavior. The XFEM technique is based on arbitrary crack propagation, so the initial crack path and top-bottom parts of the DCB specimen are not required to define in the XFEM technique. The XFEM technique was employed with VCCT and CZM techniques using the enrichment function. The stress-based criteria was used for crack initiation, whereas the energy-based approach was used for crack propagation in DCB laminate. The numerically simulated responses were compared with the published experimental load-displacement responses and agreed well. A parametric study of various fracture parameters (cohesive strength, fracture energy, interfacial stiffness, laminate thickness, and pre-crack length) was conducted to understand their effects on load-displacement responses of the Mode-I interlaminar fracture. The several fracture modeling techniques were compared by considering the element type, shape, total elements, accuracy, run-time, increments, and convergence speed. The surface-based fracture modeling approaches showed a high dependency on mesh size. All the fracture modeling approaches validate the experimental trend; however, the three-dimensional XFEM-CZM technique showed excellent accuracy with moderate mesh dependency and took the highest computer consumption time. Thus, it was found as the most significant interlaminar fracture modeling technique for the prediction of crack behavior to a large extent.