A visco-hyperelastic approach to model rate dependent compaction response of a 3D woven fabric

Abstract

In composites manufacturing processes, such as Liquid Composite Molding (LCM), compaction of a fabric preform is a key processing step. For developing process models of such manufacturing techniques, modelling of the compaction response of the reinforcement is vital. Woven fabrics exhibit a complex viscoelastic compaction response that depends on the architecture and properties of the reinforcement. In this work, we experimentally investigated the rate-dependent response of a 3D orthogonal woven fabric under different loading histories such as, slow-rate compaction, single step compaction, multi-step compaction and cyclic loading tests. A visco-hyperelastic modelling approach was used with a modified Maxwell-Weichert rheological model to describe the viscoelastic compaction behaviour of the 3D woven fabric. The rheological model consists of microstructure-dependent spring elements and Maxwell elements arranged in parallel. The microstructure-dependent spring element accounts for the non-linear rate dependent equilibrium behaviour of the fabric and is described by modified Gutowski’s compaction model. Hyperelastic strain energy functions, such as, Yeoh and NeoHookean, were used to describe the stress response in each Maxwell element. A nonlinear evolution law was adopted to derive an expression for the dissipation rate and deformation in the dashpots of each Maxwell element. The identification of the visco-hyperelastic material parameters was performed and validated against the experimental data.