A note on the Monte Carlo simulation of the tensile deformation and failure process of unidirectional composites

Abstract

Instead of using a microcomposite model with a coarse mesh and a few fibres of short length, the present paper uses a two-dimensional model with fine mesh, sufficient fibres and adequate length to carry out a new Monte Carlo simulation to study the tensile failure process of unidirectional composites. After examination in many ways, it is shown that this method is simple, intuitive and effective. Once the strengths of fibre elements are randomly allocated, the composite apparent stress/ strain curves are reliably predicted, and the developing mesostructure (the damage evolution process) is exactly simulated. By simulation, the damage evolution process following fibre breakage is revealed, i.e. following the rupture of fibres, micro-cracks form and grow stably until critical micro-cracks are produced. The present paper also discusses the effect of local matrix failure and points out that the ductility of the matrix and the fibre failure strain must obey a coupling relation in order to utilize fully the advantage of the high strength of the fibres.