Experimental and Numerical Study on Mechanical Properties of Z-pins Reinforced Composites Adhesively Bonded Single-Lap Joints

The mechanical properties of Z-pins reinforced composites adhesively bonded single-lap joints (SLJs) under un-directional tension loading are investigated by experimental and numerical methods. Three kinds of joint configurations, including SLJs with three/two rows of Z-pins and "I" array of Z-pins, are investigated by tension test. The failure modes and mechanism of reinforced joints with different Z-pins numbers and alignment are analyzed, and the comparison is performed for the failure strengths of no Z-pins and Z-pins reinforced joints. According to experimental results, failure modes of three kinds of joints are all mixed failure. It turns out that the Z-pins are pulled out ultimately. The strength of joints of more Z-pins at the end of the overlap area is relatively bigger for the joint of the same Z-pins numbers. The strength of joints with Z-pins compared with non Z-pins joints is growing at 16%. Finally, the three-dimensional distribution of interfacial stress in the lap zone of three kinds of Z-pins reinforced joints is simulated, and the numerical results are in good agreement with the experimental results. It is effective that the numerical calculation of stress analysis is verified.