Damage Failure Analysis of Z-Pins Reinforced Composite Adhesively Bonded Single-Lap Joint

In order to study the mechanical properties of Z-pins reinforced laminated composite single-lap adhesively bonded joint under un-directional static tensile load, damage failure analysis of the joint was carried out by means of test and numerical simulation. The failure mode and mechanism of the joint were analyzed by tensile failure experiments. According to the experimental results, the joint exhibits mixed failure, and the ultimate failure is Z-pins pulling out of the adherend. In order to study the failure mechanism of the joint, the finite element method is used to predict the failure strength. The numerical results are in good agreement with the experimental results, and the error is 6.0%, which proves the validity of the numerical model. Through progressive damage failure analysis, it is found that matrix tensile failure of laminate at the edge of Z-pins occurs first, then adhesive layer failure-proceeds at the edge of Z-pins, and finally matrix-fiber shear failure of the laminate takes place. With the increase of load, the matrix-fiber shear failure expands gradually in the X direction, and at the same time, the matrix tensile failure at the hole edge gradually extends in different directions, which is consistent with the experimental results.