Finite element modelling of fibre-reinforced brittle materials

The tensile constitutive behaviour of fibre-reinforced brittle materials can be extended to two or three dimensions by using the finite element method with crack models. The three approaches in this study include the smeared and discrete crack concepts and a multi-surface plasticity model. The tensile relation represents the crack normal stress-normal strain behaviour. Depending on the fracture mode - single or multiple - different modelling strategies must be considered. Applications in this study include a short steel fibre-reinforced densified small particles (DSP) beam, kevlar fibre-reinforced beams with and without ordinary reinforcing bars, and a steel fibre-reinforced concrete pipe. The increase of the peak load due to fibres could be reproduced, which supports the validity of the proposed method. All the tensile relations have been computed from micromechanical properties. Some micro mechanical properties have been obtained by trial and error by fitting to experimental results. Once the micromechanical properties are fixed, a parametric study is possible by varying e.g. the fibre content or fibre length