An etching based axisymmetric solution for the determination of residual stresses in long fibre reinforced metal matrix composites

Abstract

Thermal residual stresses arise in long fibre reinforced composites such as metal matrix composites due to the mismatch of the thermal and mechanical properties of the constituents and the change in temperature during processing. This paper presents an inverse axisymmetric model that uses the fibre deformation obtained when the matrix is selectively etched away in order to back calculate the inherent residual stresses. The model is tested using finite element method simulation and also on published experimental data. Although, an approximate inverse solution exists in the literature, there is an ambiguity in the value of Poisson’s ratio to be used which can lead to large errors relative to the full solution presented in this paper. A sensitivity analysis is also carried out to quantify the effect of variability of material properties on the stress values obtained using the solution.