SH Waves in A Functionally Graded Nano Copper Layered Wafer

To solve the problem of SH wave propagation in a functionally graded nano copper layered wafer, in this paper the power series technique is employed to solve governing equations with variable coefficients. SH waves in a single-layer structure and a multi-layered structure are investigated. The results show that multiple modes for SH waves exist in functionally graded nano copper wafers, the gradient property leads to decreased phase velocity, and the absolute value of the phase velocity variation is positively correlated with the gradient coefficient. Both the phase velocity variation and the phase velocity variation rate in Mode 2 are small compared with the other modes. Mode 4 is recommended for nondestructive evaluation. These results should provide theoretical guidance for nondestructive evaluation in functionally graded nano material layered structures.