Research Progress on Analytical and Numerical Prediction of Curing Deformation in Thermoset for Large Composite Parts

Solidification deformation will produce certain drawbacks, so that a composite material part may not meet the requirements of a stress-free assembly for a modern aircraft. This issue holds particularly in the composite material part of large aircrafts. To predict and control this deformation, a novel method is applied for shifting the relaxation times of the composite based on its temperature and degree of cure. The choice of a suitable material model to simulate induced distortions is important to achieve the right-first-time approach. This work investigates the ability of the multi-physics model within a linear viscoelastic material model to predict induced distortions into an aerospace composite wing. It is shown that a L-shaped stiffened wall was less dominated by all deformations, but two stiffened wall panels were more dominated. Yet, wing box panels with four stiffened wall panels reduced the contribution to deformation. Their effects were included in the theory reported for the curing, and found to account for approximately 6.25% of the part deformation. The deformation effect could be analyzed by the proposed analytical solution, which was coupled with a cure kinetics model and a chemical shrinkage model to capture the multi-physics that take place during the curing.