A Multiscale Infusion-cure Modeling Framework to Predict the Residual Stress of a Vacuum Assisted Resin Transfer Molded Composite

Abstract

The purpose of this paper is to develop an experimentally-validated integrated infusion-curing model to predict the resin flow front and the residual stress inside the plain weave composite manufactured using the Vacuum Assisted Resin Transfer Molding (VARTM) technique. The composite is made of 16 plies plain weave AS4 carbon fiber fabrics, and the matrix is EPON 862/W resin system. In the infusion model, the dry fiber fabrics are treated as a homogeneous, porous material, and the resin flow front is predicted using the Volume of Fluid (VOF) method. Due to the interaction between the flow movement and fiber structural deformation, the resin flow model created in STAR-CCM+ and the fiber structural model created in Abaqus are two-way coupled. After the infusion simulation, the deformed shape of the composite is passed into the curing model to predict the residual stress development in the curing process. In the curing model, each lamina is treated as a homogeneous orthotropic material with the effective viscoelastic properties calculated from the fiber modulus and resin relaxation modulus using the correspondence principle and the micromechanics models, and these effective composite properties are included in a 3D anisotropic viscoelastic constitutive law to predict the residual stress increment. The accuracy of the proposed model is assessed by comparing the predicted flow front and the thickness of the composite structure after cure against the experimental results.