Modeling the viscoelastic behaviour of fibre reinforcing fabrics

Abstract

The deformation of fibrous materials plays an important role in the Liquid Composite Molding (LCM) processes. These materials display markedly non-linear viscoelastic characteristics. A model of fibrous material deformation is developed, incorporating this non-linear viscoelastic response, with a view to being used in simulations of LCM processes. The model is one-dimensional and is appropriate for the simple fibre compaction deformation which occurs during LCM processes. A limited number of compaction experiments were carried out to determine the model parameters for a continuous filament mat. These included a rapid compaction (100mm/min), a number of slower compactions to the same final volume fraction, and then a number of tests at a constant compaction speed to different final volume fractions. The model gives reasonably good results over a range of compaction speeds and volume fractions.