Stress analysis in a three phase material with fibre, coating and matrix

A new model for the stress state analysis in the single fibre specimen with 3 phases, fibre, coating, and matrix, is developed. The stress distributions in radial and axial directions are obtained using the principle of minimum complementary energy. Assumptions made to simplify the stress analysis are: a) axial stress distribution is uniform across the fibre cross-section; b) axial stress distribution is uniform across the coating thickness; c) the non-uniform axial stress distribution in the matrix is given by a decreasing function containing a free parameter which is obtained by minimization procedure. The developed model is used in parametric analysis to determine the effect of the coating properties and geometry on the rate of the stress transfer and shear stress concentration at the fibre end.