Finite element modelling of damage development during longitudinal tensile loading of coated fibre composites

This paper presents the results of finite element calculations for determining the stress state near a broken coated fibre in unidirectional carbon fibre — epoxy matrix composites. The influence of coating thickness, coating stiffness and assumed crack pattern on the stresses in the broken fibre and in adjacent, unbroken fibres is evaluated and their possible impact on composite longitudinal tensile strength is discussed. For this analysis, a two-dimensional axisymmetric model was developed and all the elastic constants of the coated fibre composite were separately calculated and used as input data in the model.