Tensile behaviour of glass fibre reinforced polyurethane at different strain rates

This paper is concerned with the modelling of the tensile behaviour of glass fibre reinforced polyurethane under variable strain rates. This particular composite has viscoelastic behaviour with both elasticity modulus and ultimate tensile strength being strongly dependent of the strain rate. It is proposed an one-dimensional viscoelastic phenomenological damage model able to perform a physically realistic description of the strain rate sensitivity. The aim is to predict the stress–strain behaviour at different strain rates using model equations that combine enough mathematical simplicity to allow their use in engineering with the capability of describing the mechanical behaviour. The materials parameters that appear in the model can be easily identified from only three tests performed at constant strain rates. Modelling prediction showed good agreement with experimental results.