Estimation Method of Young's Modulus of Thermal Barrier Coating Layer Based on Free Bending Vibration

Abstract

A simple method for measuring Young's modulus of a coating layer is proposed based on a free bending vibration, and an experimental approach, by which a first-mode natural frequency of a flexuaral vibration produced by an impact of hammer is measured, is tried to estimate Young's modulus of the coating layer. The natural frequency equation with variable of the specimen geometries and Young's modulus is obtained by Timoshenko beam theory, and then Young's modulus of the coating layer is estimated by minimizing the objective function defined from the natural frequency equation. The proposed measuring method is applied to PMMA coating and thermal barrier coating. It is shown to be able to estimate the Young's modulus of both of coatings by the proposed method with good accuracy.