Research On Preparation Process And Mechanical Properties Of The Laminates Reinforced With Z-pin

As a new technology of three-dimensional reinforced composite materials, The research of Z-pin reinforced composite laminate in China is in the initial stage. This paper focuses on the automatic forming technology, improve the efficiency of CNC machines, produce the Z-pin ultrasound implant system, thus enabling the Z-pin reinforced laminated structure. To meet the need of heat resistance for aviation, the pultrusion parameters of FW-77 high-temperature epoxy resin were set, and carbon fiber/BMI composite Pin samples are successfully manufactured. study the different parameters of the Z-pin reinforced composite laminates systematic.Several kinds of Z-pin reinforced samples are made for studying the tensile property, shear property and interlaminar fracture toughness. The results show that tensile modulus of elasticity decreases with the Z-pin's diameter and the volume fraction, the tensile modulus increases with Z-pin's implantation angle. Z-pin's implantation angle had no obvious effect of vertical and horizontal shear property, with the Z-pin's volume content increase, the shear strength and modulus decrease. Z-pin can significantly improve the laminate typeâ…¡fracture toughness of GIIC value.As an application to explore, Enhance the weakest connection thread jionts of Z-pin reinforcement, the results show that the strength of the joints was improved obviously. Z-pin improve the stress distribution of the thread tooth on the axial tension loads, and raise the interlaminar shear strength. This paper also study on the failure mechanisms and the delamination toughening mechanisms of Z-pin reinforcement. Pullout of the Z-pin forms a bridging zone along the delamination that prevent the diffusion of the cracks.