Experimental Study on Permeability and Infusion Simulation of Automatically Placed Dry Fiber Preforms

To investigate the resin infusion molding process for novel dry fiber-reinforced epoxy composite wing skin, dry fiber preforms were fabricated via an automated fiber placement (AFP) system, and the out-of-plane permeability of the preforms at different lay-up speeds was measured using the ultrasonic transmission method to determine the optimal lay-up parameters. A scaled-down composite wing skin structure was modeled and meshed via numerical simulation, and different resin infusion schemes were simulated and analyzed using PAM-RTM software. The optimal infusion scheme was determined by comparing the infusion time, infusion pressure and defect formation during resin flow for different schemes, and the wing skin component was fabricated through the vacuum-assisted resin infusion (VARI) process. Results indicate that the infusion time predicted by PAM-RTM simulation is 3883 s, while the actual measured value in the VARI process is 3611 s with an error of approximately 7% within a reasonable range. Both simulation and actual wing skin fabrication exhibited no significant defects, validating the accuracy of the three-dimensional permeability measurement of dry fiber preforms as well as the reliability of the simulation results.