Thermal stresses in hybrid materials with auxetic inclusions

We study thermo-elastic behaviour of the hybrid materials with auxetic inclusions. To this end we analyse representative volume elements consisting of a large number of randomly positioned cubic inclusions using the finite element method and determine the effective coefficient of thermal expansion and the average thermal stresses in constrained hybrid materials developed as a result of a uniform temperature change. We study the effect of Poisson's ratio, Young's modulus and the coefficient of thermal expansion of the inclusions on the effective coefficient of thermal expansion and thermal stresses. We demonstrate that the auxeticity of the inclusions can reduce thermal stresses, which is controlled by the values of the Poisson's ratio and the coefficients of thermal expansion of the inclusions and matrix.