Influence of resin curing during mold filling on process‐induced residual stresses and deformations in ultra‐thick vacuum‐infused laminates: A multiphysics approach

Abstract In this study, the impact of resin curing during the mold‐filling, flushing, and bleeding stages of the vacuum infusion (VI) process on the process‐induced residual stresses and deformations in ultra‐thick composite laminates is numerically investigated. For this purpose, a two‐dimensional code namely VIsim has been developed, which can simulate non‐isothermal mold filling using reactive fluid, flushing, bleeding, curing, and evolution of residual stress in the laminate. The VIsim code employs a synergistic approach by integrating finite element/control volume (FE/CV) and streamline‐upwind‐Petrov‐Galerkin (SUPG) methods to address the simulation challenges effectively. Moreover, VIsim has been validated by simulating three experimental test cases previously investigated in the literature. Among the various applications of ultra‐thick laminates, one notable use is in the root sections of wind turbine blades. The study is focused on analyzing a flat E‐glass/epoxy laminate with a thickness of 100 mm and a length of 1 m. The results demonstrate that considering resin curing during the first three stages (mold filling, flushing, and bleeding) of the VI process significantly influences the laminate deformation type and has a notable impact on the magnitudes and distributions of longitudinal and interlaminar normal residual stresses in ultra‐thick laminates. Highlights Resin curing during mold filling influences process‐induced residual stresses. Considering resin curing in mold filling may alter the laminate's deformation type. The VIsim code has been developed and validated to simulate the VI process. VIsim integrates FE/CV and SUPG methods to address the simulation challenges.