Exact elastic analysis of a doubly coated thick circular plate using functionally graded interlayers

Development of new coating systems has been an important issue over the years with the motivation of extending the effective life of mechanical elements. For this intent, functionally graded materials have been recently used in a variety of applications as promising replacements for conventional coatings. In the present study, a hybrid coating system taking advantage of graded composition concept is proposed to enhance the through-thickness stress distribution within a double-sided coated circular thick homogeneous plate. The coating system is composed of two main layers: an external homogeneous layer and an interlayer between the external layer and the plate, with graded material composition. All layers are modeled within the context of three-dimensional elasticity theory, and an elasto-static solution is obtained by using suitable potential functions. Accuracy and reliability of the proposed analysis is investigated by comparison with results obtained in the literature, as well as with the results of a three-dimensional finite element simulation. Comparative study shows the inherent advantages of the present hybrid coating system over the conventional homogeneous coating or the functionally graded coating layers.