Analysis For Thermal Elastoplastic Stresses Of Functionally Graded Coating

The theoretical model of analysis for thermal elastoplasticity of functionally graded materials has a very important significance to its design and development. With the focus on the structure and components character of plate metal/ceramics graded coating, this paper extends and improves the thermal elastoplastic analysis model of trilayered materials derived by Suresh et al and builds the theoretical model of thermal elastoplastic stresses analysis of plate metal/ceramics graded coating, and this paper also analyzes the thermal elastoplastic stresses and deformation of metal/ceramics graded coating.This paper firstly extends the thermal elastoplastic deformation theory of trilayered materials derived by Suresh et al and abolishes the restrictive assumption to the monodirectional spread of plastic zone in the original model and the thermal elastoplastic analysis model which reflects the complete history of thermal elastoplastic deformation of the multilayered materials is built. This model can be also applied to the condition of the spread of plastic zones from both sides of plastic layers and has more applicability compared to Suresh et al's model.This paper also researches on thermal elastoplastic analysis model of multilayered graded coating structures on the basis of thermal elastoplastic analysis model of trilayered materials with the focus on the structural character of graded coating. It builds the thermal elastoplastic analysis theory for the graded coating structure that has a single plastic layer or two plastic layers. It gives the analytical formulas of thermal stresses and the thermal elastic-plastic transform temperatures of graded coating that has a single plastic layer or two layers under the thermal loading. It tests the theoretical model with finite element analysis.Finally, this paper calculates the residual stresses distribution ofmultilayered graded coating structures with the theoretical model built in the paper and the elastic model, and it discusses the influences of material's plasticity to the thermal stresses of the graded coating.With this paper's study, we can understand the history of thermal elastoplastic deformation and thermal stresses of graded coating more deeply. This paper builds a model which can better describes the thermal elastoplasticity of metal/ceramics graded coating and multilayered materials, and it builds the theoretical basis for the optimized design and thermal elastoplasticity analysis of metal/ceramics graded coating and multilayered materials. The research of this paper has important guidance significance to the engineering application of the graded coating.