A novel method for shear horizontal surface waves in periodically layered semi-infinite structures with coating layers

Abstract

The motivation of this paper is to draw attention to the research of shear horizontal (SH) surface wave dispersions in periodically layered semi-infinite structures with coating layers. Based on the properties of the symplectic matrix, a series of important conclusions regarding this subject are presented and confirmed. The propagation behaviour of SH surface waves in periodically layered semi-infinite structures can be analysed using only a single unit cell, which implies a significant reduction in the computational cost. Then based on the Wittrick-Williams (W-W) algorithm, the proposed method was extended to predict SH surface waves in periodically layered semi-infinite structures with coating layers. All eigenfreqencies can be computed by using the concept of the eigenvalue count. Two types of boundary conditions (free and clamped surfaces) are considered in this study. Finally, serval numerical examples are provided to illustrate the performance of the proposed method, which involves a comparison with previously published results and results obtained via the seeking root technique.