A multiscale modeling framework for predicting the viscoelastic–plastic behavior of thin-walled composite deployable structures

Thin-walled composite deployable structures have garnered significant attention in space applications due to their unique folding and deployment capabilities. However, their long-term stowage and recovery performance is strongly influenced by viscoelastic–plastic (VE-P) behavior, which remains insufficiently understood due to the lack of rigorous modeling methodologies. To address this challenge, we develop a multiscale modeling framework to characterize the time-dependent and plastic responses of thin-ply high-strain composites employed in such structures. Constitutive VE-P models are formulated at multiple scales: an isotropic VE-P model is constructed for the polymer matrix, while two anisotropic VE-P models are developed for unidirectional fiber yarns and woven composite laminae. The polymer matrix parameters are calibrated using experimental data. Representative volume element (RVE) models at the microscale and mesoscale are employed to compute the effective VE-P properties of the unidirectional yarns and woven laminae, respectively. The anisotropic VE-P model is then implemented in finite element analyses to simulate the time-dependent and plastic behavior of the composite lamina, with predictions validated against experimental measurements. Finally, the constitutive model is applied at the macroscale to simulate the folding, stowage, deployment, and recovery processes of a particular thin-walled composite lenticular boom, capturing key behaviors such as shape recovery and permanent deformation. The results confirm the efficiency and reliability of the proposed multiscale approach for evaluating the stowage and recovery performance of composite deployable structures.