Abstract
A theoretical model has been developed to investigate the effects of through‐thickness pinning (z‐pin) on mode I delamination. Computer simulation results are presented to understand the mechanism of z‐pin reinforcement. Bridging force of the z‐pin is calculated by a single pin pull‐out model. Numerical results of the fracture load versus mode I delamination crack growth are obtained. Effects of the areal density, radius and Young's modulus of z‐pin are also studied. By assuming different interfacial friction coefficient, the effect of pin/laminates friction is discussed.