A novel model for predicting deformation of thermoplastic composites during heat-pressing process

Carbon fiber/polyetheretherketone (CF/PEEK) thermoplastic composites are widely used in the aerospace industry due to their excellent mechanical properties and high-temperature resistance. However, the research on heat-pressing deformation and residual stress during high-temperature and high-pressure heat-pressing processes in CF/PEEK was relatively deficient. In this paper, a framework coupled with crystallization kinetics, micromechanics and thermodynamics was developed to predict the heat-pressing deformations of CF/PEEK and it was conducted by UMAT, DISP and UEXPAN subroutines. Moreover, the predictive model was verified by experiments effectively. Finally, we compared the difference in residual stress distributions between symmetric and asymmetric lay-ups and found that the melting temperature, thickness, angle and sequence of layers have a significant impact on the heat-pressing deformation. This work provided an effective tool for predicting heat-pressing deformations, which is great of significance in the manufacturing and application of CF/PEEK.