A virtual framework for prediction of full-field elastic response of unidirectional composites

This paper presents a virtual framework for deriving a full-field elastic response of continuous fibre unidirectional (UD) composites using a micromechanical modelling approach. This implies determining all possible elastic constants for the UD composite based solely on knowledge of the constitutive behaviour of the composite constituents. The framework is based on a microscale three-dimensional representative volume element (3DRVE) of a test composite, with random spatial arrangement of the fibre reinforcement. The 3DRVE was determined based on a Monte Carlo style geometric model generation algorithm. Periodic boundary conditions and representative loading cases were prescribed on the 3DRVE to determine the microscale response of the test composite. Appropriate lengthscale bridging algorithms, modelled after a 2D RVE direct macro–micro homogenization approach – but here extended to 3D RVEs, were used to determine macroscale properties of the test composite. The virtual framework has been validated against experimental data and the model was shown to give reliable predictions. Also, in comparison with other comparable computational, analytical and semi-analytical micromechanical models, the proposed framework was shown to give the widest holistic set of elastic properties of the test composite. This framework represents a suitable substitute for realistic experiments and therefore can be used in design of different virtual experiments. Parametric studies have also been carried out and interesting conclusions drawn on the constitutive behaviour of the test composite while also exploring the different features of the virtual framework.