Effect of process parameters on interlaminar properties of thermoplastic composite: Molecular dynamics simulation and experimental verification

Interlaminar properties are one of the most important indicators of thermoplastic composite quality. In this paper, the unidirectional carbon fibre reinforced polyether ether ketone (CF/PEEK) thermoplastic composite was taking as the research object, an all-atom model constructing method of the interlaminar interface was proposed, the influence mechanism of process parameters including forming pressure and temperature on interlaminar properties were studied by molecular dynamics (MD) simulation and experimental verification. The simulation results showed that a reasonable forming pressure could promote the non-bonded interaction between polymer molecules, and an appropriate raising of forming temperature could promote the thermal motion of polymer molecules, which was conducive to the interlaminar diffusion and penetration of polymer, thereby improving the interlaminar bonding strength, the interlaminar properties were more sensitive to the changes of forming temperature than pressure. The experimental results were in good agreement with the MD simulation result in terms of the significance and the trend of process parameters influence on the interlaminar properties. Illustrating that it is effective to explore the forming mechanism of thermoplastic composite and guide the forming process by MD simulation.