Under the influence of extrinsic curing conditions and intrinsic properties of carbon fiber reinforced resin composites, the formation of curing deformation is inevitable, which makes the shape of the manufactured components differ from the designed structure, and even exceeds the assembly tolerance, resulting in the scrap of parts. Therefore, it is very urgent and important to optimize the curing deformation of carbon fiber reinforced resin composites. In this paper, the mechanism of stress and curing deformation is reviewed firstly, and then the factors affecting the curing deformation are summarized. In particular, from the point of view of materials in curing process, three curing deformation control strategies, including (i) reinforcement structure optimization, (ii) resin modification and process optimization, (iii) die surface compensation and tool‐part contact optimization, were proposed. And with the development of curing deformation simulation technology, the (iv) inverse design strategy before curing and (v) hot sizing method from the view of after cured were further put forward, respectively. By analyzing the link between processing details and curing deformation, it is found that the dominant factor affecting deformation may change under different conditions, so the interaction between factors needs to be further discussed. Subsequently, the effect of these distortion control methods on curing deformation was analyzed and evaluated, and the shortcomings were pointed out. Finally, the challenges existed in curing deformation research were identified, in order to contribute to the development of curing deformation research.

A composite thin shell with a high fiber volume fraction prepared by resin transfer molding (RTM) may have void defects, which create deformations in the final curing and lead to the final product being unable to meet the actual assembly requirements. Taking a helmet shell as an example, a multi-directional compression RTM (M-CRTM) method with an adjustable injection gap is proposed according to the shape of the thin shell. This method can increase the injection gap to reduce the fiber volume fraction during the injection process, making it easier for the resin to penetrate the reinforcement and for air bubbles to exit the mold. X-ray CT detection shows that the porosity of the helmet shell prepared by the newly developed technology is 36.6% lower than that of the RTM-molded sample. The void’s distribution is more uniform, and its size is decreased, as is the number of voids, especially large voids. The results show that the maximum curing deformation of the M-CRTM-molded helmet shell is reduced by 13.7% compared to the RTM molded sample. This paper then further studies the deformation types of the shell and analyzes the causes of such results, which plays an important role in promoting the application of composite thin shells.

This paper studies the ballistic impact performance of 3D woven composites (3DWCs) with hexagonal binding patterns. Para-aramid/polyurethane (PU) 3DWCs with three kinds of fiber volume fraction (Vf) were prepared by compression resin transfer molding (CRTM). The effect of Vf on the ballistic impact behavior of the 3DWCs was analyzed by characterizing the ballistic limit velocity (V50), the specific energy absorption (SEA), the energy absorption per thickness (Eh), the damage morphology and the damage area. 1.1 g fragment-simulating projectiles (FSPs) were used in the V50 tests. Based on the results, when the Vf increases from 63.4% to 76.2%, the V50, the SEA and the Eh increase by 3.5%, 18.5% and 28.8%, respectively. There are significant differences in damage morphology and damage area between partial penetration (PP) cases and complete penetration (CP) cases. In the PP cases, the back-face resin damage areas of the sample III composites were significantly increased to 213.4% of the sample I counterparts. The findings provide valuable information for the design of ballistic protection 3DWCs.

In the process of preparing textile composites by resin transfer molding (RTM) method, both the upper and lower surface of the mold will interact with the composite parts due to the mismatch of thermal expansion coefficient between the mold and the part, resulting in warpage deformation. To address this key technical problem, this article first studied the effect of mold on the warpage deformation of composite material under different fiber volume fractions. Then a mold–part interaction modeling method for RTM process with nonthermoelastic deformation is proposed. By introducing shear layers between the upper and lower surfaces of the mold and the composite part, a finite element simulation model for predicting the curing deformation of the component is established and experimentally verified. The results show that the effect of mold–part interaction on the warpage deformation of the composite decreases with increasing fiber volume fraction. Meanwhile, the proposed modeling method can avoid complete material characterization, and the comparison between experimental and simulation results proves that the model can accurately simulate the curing deformation of composite components under the same process conditions. Finally, the analysis reveals that the interaction caused by thermal mismatch between the composites and the mold is less related to the intermediate layup, but mainly related to the fiber orientation of the layup layer in contact with the mold.Highlights The warpage deformation law of the mold on the composites with different fiber volume fractions is investigated. A mold–part interaction modeling method for a resin transfer molding process with nonthermoelastic deformation is proposed, where the mold stretching effect is represented by the cumulative effect of the interaction between the two layers on the upper and lower surfaces of the part.