The mechanism of wrinkle defects affecting the curing process and their coupling with residual stresses on the compressive mechanical properties of UD thick-section composites

Understanding the mechanisms that influence wrinkle defects is crucial because they are likely to occur during the manufacture of thick-section composite materials, which weaken the materials’ mechanical properties. However, few existing studies have explored how wrinkles affect the curing process or their interaction with residual stresses that influence the material’s mechanical behavior. This paper develops a thermo-chemo-mechanical coupled numerical simulation method for the curing process of thick-section composite materials with wrinkle defects and investigates the impact of wrinkles on curing. It is found that wrinkle shape affects the temperature distribution during the initial stage of curing and significantly influences the stress field. Additionally, a finite element model coupling wrinkle defects and post-demolding residual stresses is developed to analyze how the interaction between wrinkles and residual stresses affects the compressive mechanical properties of UD composites. The results show that the post-demolding residual stress exerts a limited effect. In contrast, wrinkles exert a decisive influence on the compressive mechanical properties, which can even reduce the compressive strength by approximately 50%.