Optimization Forming Process of CFRP I ‐Shaped Stiffened Panel

ABSTRACT Carbon fiber reinforced polymer (CFRP) stiffened panels are widely used as primary load‐bearing structures due to their high strength‐to‐weight ratio. However, their forming process is susceptible to deformation and defects influenced by factors such as mold material, lay‐up sequence, curing temperature, and heating rate. This study presents a simulation‐based method for optimizing the forming process of CFRP I‐shaped stiffened panels. The numerical model integrates thermochemical analysis with a cure‐hardening instantaneous linear‐elastic model. Optimization of the lay‐up design, including the strategic addition of 0° plies, successfully suppressed torsional deformation in the upper flange and reduced overall panel distortion. The simulations indicate that both curing deformation and residual stress increase with higher curing temperatures and faster heating rates. Numerical and experimental results converged to identify an optimal process utilizing a rubber/stainless steel composite mold, a curing temperature of 393.15 K, and a heating rate of 2 K/min. This optimized setup reduced deformation and residual stress by 23% and 22%, respectively, compared with the baseline aluminum mold process. The proposed strategy significantly enhances the forming accuracy of CFRP stiffened panels and provides.