Research On Preparation Process And Mechanical Properties Of Z-pinned Phenolic Composite Laminates

It’s the first time for the Z-pin technology using on the heat-resistant material. The specificalcontents are as follows:(1) The pultrusion molding process of phenolic Z-pin had been studied, and the optimalperformance of the resin had been selected by the bridge value test.(2) A test method for the shear properties of the mini-rod Z-pin had been proposed to evaluateZ-pin’s interlaminar properties.(3) The curing process of the composite laminate had been optimized for the Z-pinreinforcement.(4) By in-plane tensile and in-plane compression tests, studied was Z-pins’ influence on thein-plane properties of the phenolic lamina, and results were obtained as follows:①The tensilestrength of laminates was decreased with the inserting of Z-pins;②Z-pin had a little effect on thetensile modulus of laminates;③The insertion of Z-pin had changed the failure mode of the laminaand the probability of the layer damage had been decreased.(5) By interlaminar tensile and interlaminar shear tests, studied was Z-pins’ influence on theinterlaminar properties of thephenolic laminate, which showed that Z-pinning made a greatcontribution to the increase of the interlaminar properties, and later the prediction formula of theinterlaminar properties was summarized. In addition, the influence on interlaminar properties bydifferent insertion angles (+45°、-45°) were studied. With the help of FEA and experiments, it turnedout that Z-pins functioned better in the situation that their angle ensures that they are tensiled whenthey are loaded.