Experiment And Simulation For Ti/PEEK Interfacial Fracture Toughness Of Ti/PEEK/C_f Laminates

Ti/PEEK/Cf laminates are a kind of thermoplastic and super hybrid composite laminates, formed by titanium alloy and PEEK/Cf prepreg under certain temperature and pressure, and with excellent mechanical properties and desirable features including high specific strength, specific modulus, outstanding fatigue resistance, good impact resistance and corrosion resistance.In this paper, the research is mainly on the fracture toughness of Ti/PEEK interface. Firstly, a cohesive zone model is build at the Ti/PEEK interface and some basic mechanical performance tests are implemented to obtain the parameters this interfacial model needed. Then, a finite element model and double-cantilever-beam(DCB) test are applied for evaluating and testing the interfacial fracture toughness. The fundamental mechanics performance testings are also used to establish the cohesive zone model and mesh elements. The simulated and experimental results showed that, energy release rate- crack propagation distance curve, and force- opening displacement curve are almost similar. And a better predicted finite element model is obtained at last by debugging parameters and this model is verified.Secondly, a type of interfacial morphology with circular micro-prits are created between titanium alloy and PEEK in the above predicted finite element model to research the influence of prits’ size on the interfacial fracture toughness. The simulated result suggests that, the interfacial fracture toughness of laminates with diameter of the prit at bout 300 μm is the highest, 500 μm’s takes the second place, 100 μm’s has lower value, but still higher than the lamiantes with smooth interface.Thirdly, photoetching technique is used to create prits morphology on the surface of tatinium alloy. And the double-cantilever-beam(DCB) test’s result is basically similar to the simulated result. The finite element analysis technique successfully guides the implement of experiment, achieve the purpose of improving the interfacial fracture toughness of Ti/PEEK/Cf laminates.