An Interlaminar Model for Delamination Behavior of Composite Curved Beams Considering Inter-Ply Voids

Computational methods provide effective tools for the prediction of the failure behavior of structures, especially for composites with complex failure modes. The effect of manufacturing process defects on the delamination behavior of composites receives insufficient attention in current studies. In this work, an interlaminar model for composite curved beams considering inter-ply voids was established. A classification and calculation method for calculating inter-ply porosity and intra-ply porosity is proposed based on geometry and location characteristics of voids. Then, an interlaminar model is established based on cohesive zone model with the inter-ply porosity as an input parameter. L-shaped composites with balanced and symmetry layups were cured and subjected to four-point bending tests to validate the proposed method. The numerically predicted location of initial crack generation and final delamination pattern are in great agreement with the experimental results. Besides, the prediction accuracy of the model considering inter-ply voids improves compared with the model without defects, the prediction error of the failure load is reduced from 12.8% to 2.1%. The overall framework provides an accurate and promising tool for the prediction of the delamination behavior and assessing the effects of pore defects of composite curve beams.