CHEN Zhenglin 1, ZHANG Xuefei 1, WANG Gaochao 1, WANG Xingguo 2
(1. Department of Mechanical Engineering, Nanchang Vocational College, Nanchang 330500, Jiangxi, China; 2. School of
Mechanical and Electronic Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, China)
Abstract: Aiming to use ultrasonic nondestructive approach to test the metal matrix material of ceramic coating-metal matrix-ceramic coating sandwich structure, a mathematic model for acoustic propagation and dispersion through the three different media of the sandwich structure is built on the basis of the propagation mechanism and the control equation of wave in layered medium in combination with the global transfer matrix and the continuity of the stress and displacement boundary between gas and solid or solid and solid. The influence of metal matrix physical parameters on the dispersion curve is researched. The mathematical results show that the dispersive curves for the threelayer media move to the right due to the decrease of the metal matrix material’s density or thickness. Modal S0 is more sensitive to the change of the material density in the whole frequency domain, but both modals S0 and A0 are very sensitive to the change of the material thickness.In addition, the horizontal stress of S0 modal wave is symmetrical along the direction of the medium thickness and the vertical stress is antisymmetrical.The vertical and horizontal displacements of the wave are symmetrical along the direction of the medium thickness. These provide guidance for the choice of the proper wave modal and the use of the displacement and stress calculation for detecting the parameter change of the metal matrix of ceramic coating–matrix material–ceramic coating structure for itshealth monitoring.
Key words: ceramic coating; wave control equation; layered media; dispersion curve