Development of mitigation strategies for process-induced deformations through finite elements

Abstract

The present work investigates the residual deformations arising from the curing process of composite curved parts and mitigation strategies to reduce them. Numerical simulations based on finite elements and refined structural theories are adopted and verified against closed-form solutions. The higher-order structural theories are based on the Carrera Unified Formulation, and one-dimensional models are built using layer-wise kinematics. The Cure-Hardening Instantaneously Linear Elastic constitutive model is used. The analytical formulation includes the effects of the final demolding and the in-plane deformations. Results consider spring-in and warping angles after the tool removal. The numerical efficiency of the one-dimensional model allows for thorough parametric analyses, and all the possible combinations of an eight-layer cross-ply laminate are considered. The results confirm that the in-plane deformation and the final demolding play a fundamental role in process-induced deformations. Furthermore, deformations can be significantly reduced by considering asymmetric laminates and localized composite patches.