Research on the dynamic coupling mechanism of layup directions and process parameters in CF/PAEK laser-assisted automated tape placement

Unidirectional carbon fiber reinforced composites exhibit significant anisotropy. In the laser-assisted automatic tape placement (LATP) process, the dynamic coupling mechanism between ply orientation and process parameters is crucial for achieving high uniformity in performance. This paper conducted experiments to investigate the relationship of “Layup Direction-Dynamic Response-Interlaminar Performance." Two sets of orthogonal experiments of CF/PAEK cross-ply (CP) layers [0°/90°] 6 versus unidirectional (UD) layers [0°] 12 were designated and variance contribution analysis was used to quantify the process parameter effects on layup directions. Through infrared thermography and high-speed imaging techniques, the dynamic coupling mechanism between layup directions and process parameters was elucidated during placement. The findings indicate that CP laying is more sensitive to the laser power and are less influenced by the tape tension. Non-uniform fiber distribution leads to surface waviness, resulting in a higher susceptibility of the CP laying interface to thermal decomposition pores. Due to the obstruction of crossed fibers, CP laying is more difficult to form intimate contact than UD laying. Additionally, cross-ply laying achieves greater energy efficiency owing to the focused transverse scattering, thus it is necessary to reduce the heat input for placement. Based on the working conditions of CP laying, targeted optimization of process parameters has improved the ILSS (Interlaminar Shear Strength) of CP laminates by 25.45%. This study introduces an optimization method for process parameters based on layer angles, offering a theoretical foundation for the cross-ply placement of carbon fiber reinforced thermoplastic composites.