Study on the resin infusion process based on automated fiber placement fabricated dry fiber preform

Abstract

In this paper, a combination process of automated fiber placement (AFP) of dry fiber and vacuum assistant resin infusion (VARI) was developed, that is firstly a dry fiber preform was fabricated by AFP, and then following a VARI and oven curing process to manufacture the final composite structures, which is expected to be an alternative proposal to the traditional autoclave process, thus making the manufacturing of high performance out-of-autoclave composite structures possible. This research devotes to analyze the character of AFP fabricated preform and its influence on the resin infusion process and the obtained composite. Firstly, the features of dry fiber tapes were analyzed, and a structure model was proposed to illustrate the key factors and issues during the coupled AFP/LCM process. Secondly, the effects of AFP fabricated preform on the resin infusion process and composite performance were analyzed by comparing with manually layup competitors using the same epoxy resin system. It has been demonstrated that the AFP processed preform helps to decrease the porosity from 2.00% to 0.6% and coefficient of thickness variation from 8.11% to 3.75% while improve the fiber volume fraction from 47.80% to 56.30%, however, it prolongs the injection time by 107.71% in this experiment due to lower permeability. Reasonable design of resin flow path and precise control of resin dosage are important for a successful resin infusion process based on AFP fabricated preform. The research can provide preliminary data accumulation and technical basis for further research and future application of AFP based LCM technology in airplane structures.