The purpose of this study is to predict the curing deformation of a foam-filled free-curved surface composite part and reduce the occurrence of curing deformation through process optimization. This research introduces a finite element simulation method and an optimization method for forming parameters for a foam-filled free-curved surface composite part. Meanwhile, sample manufacturing experiments and a comparative analysis between the simulation and actual objects were conducted. The results showed that finite element simulation analysis could effectively predict the curing deformation of the composite part. After the optimization simulation analysis of the molding process parameters, it was found that the curing deformation of the foam-filled free-curved surface composite part could be as small as 2.30 mm.

With the high precision requirements and the trend of large-scale composite parts, the development of composite molds is imminent. The short carbon fiber (SCF) composite mold is mainly prepared by the technological process flow of composite sheet injection, the bonding of composite plates, and machining. However, the current process optimization method has not matured adequately, and there are still many shortcomings, for example, low precision and high cost. In this paper, the optimization method of SCF/polyetherimide (PEI) composite molds is proposed. Many experiments have been conducted, and the results show that the coefficient of thermal expansion of composite samples can be effectively reduced and the mechanical properties can be improved by optimizing the SCF weight ratio and carbon fiber length. The bonding strength of composite joints in a high-temperature environment can be improved by optimizing the bonding process parameters and modification by carbon nanotubes. Based on the above optimization method, the SCF/PEI composite mold is prepared, and the C-shaped beam composite part is fabricated by using this mold. Compared with the part made by aluminum mold, the shape accuracy of the C-shaped beam composite part is proven high through digital measurement technology.