Thickness variation in contoured composite parts by vacuum infusion

Contoured laminates were produced by vacuum infusion (VI), and thickness variations were monitored dynamically as a function of process parameters. Process simulations were performed using finite element software (PAM-RTM), and predictions of thickness along the length of the laminate were compared with dynamic measurements. Initial simulations approximated the effects of corners on preform deformation and fabric draping behavior. Subsequent modifications to the simulation geometry and material properties were implemented to increase accuracy and more closely match experimental measurements. User-defined geometry (UDG) simulations were used to predict both the maximum corner deviation and the area of corner deviation with greater accuracy. The present study demonstrates a workflow for use of analytical tools to design and control vacuum infusion processes. The workflow leverages process monitoring and modified process simulation tools to provide insight into parametric effects and to guide process modifications to reduce product variability.