The effect of temperature field on the characteristics of carbon fiber reinforced thermoplastic composites in the laying and shaping process

This work investigates the temperature field during the automated layup of carbon fiber reinforced thermoplastic composites. The heat transfer boundary conditions of the layup process are determined by establishing a mathematical model of the temperature field. The basic properties of the material are determined using CF/PEEK as the research object. The heat transfer parameters in the temperature field are analyzed to determine the thermal convection region affected by hot air and the radiated heat of the infrared lamp. And a finite element model of the temperature field is established. The FEM temperature field model was created to investigate heat transfer throughout the layup process, as well as the impact of mold heating, layup preheating, and varied heating temperatures on different layups. The temperature change law of different layups under different heating and preheating temperatures of hot air is analyzed; the online temperature measurement device is built. The experiment of automated fiber placement is carried out to analyze the heating performance of the infrared lamp and hot air gun and to determine their relevant parameters. Using the results of experiments and simulations, it has been determined that different mold temperatures are required for different layups; preheating can effectively reduce the temperature gradient between layups; and at a layup speed of 5 mm/s, a preheating temperature of 200 °C and a hot air temperature above 400 °C can ensure that the critical temperature between the prepreg wire bundle and layups reaches the melting point and they can be laid up normally.