A COMPUTATIONAL MODEL FOR CALCULATION OF MISFIT STRESS-DISTRIBUTION IN MULTILAYER CRYSTALS

A computational model is developed to calculate the misfit stress dist ribution in multilayer heterostructures. This model accounts for the e ffects of different lattice parameters and thermal expansion coefficie nts on stress distribution in heterostructures composed of different c rystal layers. The multilayer structures are treated as elastic compos ite shells with different lattice constants and thermal expansion coef ficients in different layers. A finite element formulation based on th e composite shell theory is implemented for numerical analysis of stre ss distribution in multilayer crystals. The advantages of the finite e lement approach proposed in this study are its flexibility and accurac y. Stress distributions in any multilayer structure can be calculated by this approach.