A viscoelastic-viscoplastic model for short-fibre reinforced polymers with complex fibre orientations

This paper presents an innovative approach for the modelling of viscous behaviour of short-fibre reinforced composites (SFRC) with complex distributions of fibre orientations and for a wide range of strain rates. As an alternative to more complex homogenisation methods, the model is based on an additive decomposition of the state potential for the computation of composite’s macroscopic behaviour. Thus, the composite material is seen as the assembly of a matrix medium and several linear elastic fibre media. The division of short fibres into several families means that complex distributions of orientation or random orientation can be easily modelled. The matrix behaviour is strain-rate sensitive, i.e. viscoelastic and/or viscoplastic. Viscoelastic constitutive laws are based on a generalised linear Maxwell model and the modelling of the viscoplasticity is based on an overstress approach. The model is tested for the case of a polypropylene reinforced with short-glass fibres with distributed orientations and subjected to uniaxial tensile tests, in different loading directions and under different strain rates. Results demonstrate the efficiency of the model over a wide range of strain rates

An efficient modelling of inelastic composites with misaligned short fibres

AbstractThis paper deals with the modelling of the behaviour of short-fibre reinforced composites. The composite is seen as an assembly of a matrix medium and of several fibre media. Each fibre medium, characterised by its own orientation of fibres and volume fraction, is considered as a one-dimensional elastic medium. The matrix material has an elastoplastic behaviour. All types of hardening laws can be considered, thanks to a valuable adaptivity of the modelling. The use of the Drucker–Prager criterion for plasticity and non-associative plasticity rules allow to deal with compressible plastic flow. Moreover, all kind of orientation of fibres, in particular random orientations and imperfect alignments, can be modelled in a simple way. The influence of the fibres’ orientation on the mechanical response of a polymer matrix composite subjected to tensile/compression tests is analysed in detail. Finally, simulated behaviours of composites are compared to experimental data found in the literature

A viscoelastic-viscoplastic model for short-fibre reinforced polymers with complex fibre orientations

This paper presents an innovative approach for the modelling of viscous behaviour of short-fibre reinforced composites (SFRC) with complex distributions of fibre orientations and for a wide range of strain rates. As an alternative to more complex homogenisation methods, the model is based on an additive decomposition of the state potential for the computation of composite’s macroscopic behaviour. Thus, the composite material is seen as the assembly of a matrix medium and several linear elastic fibre media. The division of short fibres into several families means that complex distributions of orientation or random orientation can be easily modelled. The matrix behaviour is strain-rate sensitive, i.e. viscoelastic and/or viscoplastic. Viscoelastic constitutive laws are based on a generalised linear Maxwell model and the modelling of the viscoplasticity is based on an overstress approach. The model is tested for the case of a polypropylene reinforced with short-glass fibres with distributed orientations and subjected to uniaxial tensile tests, in different loading directions and under different strain rates. Results demonstrate the efficiency of the model over a wide range of strain rates

A viscoelastic-viscoplastic model for short-fibre reinforced polymers with complex fibre orientations

This paper presents an innovative approach for the modelling of viscous behaviour of short-fibre reinforced composites (SFRC) with complex distributions of fibre orientations and for a wide range of strain rates. As an alternative to more complex homogenisation methods, the model is based on an additive decomposition of the state potential for the computation of composite’s macroscopic behaviour. Thus, the composite material is seen as the assembly of a matrix medium and several linear elastic fibre media. The division of short fibres into several families means that complex distributions of orientation or random orientation can be easily modelled. The matrix behaviour is strain-rate sensitive, i.e. viscoelastic and/or viscoplastic. Viscoelastic constitutive laws are based on a generalised linear Maxwell model and the modelling of the viscoplasticity is based on an overstress approach. The model is tested for the case of a polypropylene reinforced with short-glass fibres with distributed orientations and subjected to uniaxial tensile tests, in different loading directions and under different strain rates. Results demonstrate the efficiency of the model over a wide range of strain rates

Comparison Between Ultrasonic and Mechanical Young’s Modulus of a Bio-composite Reinforced with Olive Wood Floor

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