Weft Tensile Mechanical Behavior of 2.5D Woven Composite Notched Structures: Modification of Whitney–Nuismer Criterion, Simulation, and Experiment

ABSTRACT 2.5D woven composites (2.5DWC) are regarded as one of the most promising materials for future aerospace applications, but with the inevitable need for drilling holes during service, quickly predicting their strength has become a challenge for engineering design. In this work, we focus on the degree to which the yarn at the hole edge is cut. The Whitney–Nuismer (W‐N) criterion, which is only applicable to notched structures of laminated composites, is modified to apply to the rapid prediction of the strength of 2.5DWC notched structures (2.5DWC‐NS) Further, progressive damage simulations and experiments are also performed for 2.5DWC‐NS with different notch sizes and compared with the predicted values of the modified criterion. The results show that the deviation between the strength predicted by the modified criterion and the experimental data is only 15.87%, which is within the acceptable engineering deviation. Additionally, numerical simulations indicate that the stress concentration factor increases and the stiffness and strength decrease as the notch size and the area of the load‐bearing yarns at the hole edge being cut increase. Through numerical simulations, it is found that the stress concentration factor increases, whereas the stiffness and strength decrease as the notch size and the area of the load‐bearing yarns being cut at the hole edge increase. The modified criterion provides a convenient tool for the rapid design of 2.5DWC structures with significant engineering implications.