Effectiveness of compositionally linearly graded interlayers for thermal stress reduction

This work is devoted to the analysis of the effectiveness of interlayers with linearly graded composition for thermal stress reduction by using a model with closed-form analytical solution. Parameters of effective coefficient of thermal expansion, effective bending moment and effective flexural rigidity of section are introduced to facilitate the analysis. It is concluded that whether of not interlayers are useful depends on the materials' stiffness combination of the layered system. When the difference of the biaxial elastic modulus of each layer is large in the bilayer system, linearly graded interlayers do not reduce the thermal stress. The effectiveness of interlayers for curvature reduction in the bilayer system is also dependent on the materials' combination in the original layers.