Higher-order surface acoustic wave modes of a finite elastic solid

The wave mode expressions of Rayleigh waves are given by two coordinates with one in exponentially decaying form as the signature of the distinct wave feature. Such expressions are hard to expand to include their higher-order modes because they could be in two coordinates without a fixed known form. For this reason, the higher-order modes of Rayleigh waves are hard to obtain with analytical solutions, as the past attempts shown through some studies. Fortunately, our recent efforts have been shown that the Rayleigh-Ritz method is an effective technique for the analysis of Rayleigh waves in elastic solids with complications. As a result, we want to utilize this powerful method for the finding and evaluation of higher-order modes for Rayleigh waves. The essential formulation of the method has been shown in our earlier papers, and we increased the order of basis functions for the computation and search of frequencies above the Rayleigh waves to locate the higher-order modes. The process is also validated with the finite element analysis.