An axisymmetric stress analysis in a single fibre composite of finite length under a thermal expansion mismatch

In this paper, an exact solution is derived for the characterization of thermal stresses in a single-fibre composite of finite length. All the required boundary and interfacial conditions of the thermo-elastic problem are thus satisfied exactly. The proposed method involves a particular solution that is added to a three-dimensional (3D) complementary displacement field which satisfies automatically the Navier's equations. Based on experimental data provided by fibre Bragg grating sensors, an axisymmetric analysis is used then to determine the residual stress field inside the composite due to matrix shrinkage. The numerical results clearly indicate that all stress components vary significantly near the ends. An abrupt change of the shear stresses is thus predicted close to the edges. The results of the model are also found to be in good agreement with those obtained from finite element simulations. A comparison of the proposed approach with three other published theoretical models is also presented.