Fracture characterization of woven CFRP laminates-Mode I and III loading

The fracture characteristics of woven carbon fiber reinforced polymer (CFRP) under Mode I and III loading were analyzed. Two tensile testing configurations and experimental methods for simple tests under Mode I and III were employed. The Double Cantilever Beam (DCB) configuration allows for fracture characterization in pure Mode I considering the same specimen arms, using the TDCB model as the specimen’s far-field boundary. Under pure Mode III loading, out-of-plane tension at the end notch was used for fracture characterization. For R curve testing, R curves of Mode I and Mode III Tapered Double Cantilever Beam (TDCB) specimens were obtained with the assistance of infrared sensors and a servo control algorithm. During crack propagation, the stress state in the stress singularity region on crack tip was captured in detail using digital image correlation (DIC) technology. Finally, a mode partitioning method based on Cohesive Zone Model (CZM) was used for the simulation and accuracy prediction of Mode I and III mixed-mode crack propagation. These methods effectively simulated and studied the fracture behavior of composites under complex stress conditions, and provide insights into composite fracture behavior under complex stress, crucial for aerospace and automotive applications where CFRP enhances safety, reliability, and fuel efficiency.