A strain energy model for the prediction of the effective coefficient of thermal expansion of composite materials

In this paper, a strain energy model is developed for the prediction of the effective coefficient of thermal expansion (CTE) of composite materials. This model is based on the relationship established between the strain energy of the microstructure and that of the homogenized equivalent model under specific thermo-elastic boundary conditions. Expressions in closed-form are derived for the effective CTE in terms of the strain energy and effective elastic tensor. Different kinds of composites are tested to validate the model. Representative unit cells with specific boundary conditions are used to evaluate effective CTEs that are compared with available results obtained numerically and experimentally.