Thermal Stresses and Thermal Expansion Coefficients of Short Fiber Composites With Sliding Interfaces

The paper analyzes thermal stresses and effective thermal expansion coefficients of the composites in which the fiber-matrix interface is allowed to slip. Thermal stresses are evaluated by introducing an eigenstrain in the fibers, which corresponds to the strain due to the mismatch of thermal expansion coefficients. For simplicity, the effect of friction is neglected. Boussinesq-Papkovich displacement potential method is used in the analysis. Then, the results for a single sliding fiber are used to predict the average thermal expansion coefficients of the composite containing finite concentration of fibers. It is observed that sliding at the fiber-matrix interface causes higher stress concentrations and affects significantly the average coefficients of thermal expansion of the composite.