SH surface wave propagating in a strain-gradient layered half-space

By employing Mindlin’s Form II gradient elasticity theory (strain gradient elasticity theory), we investigate the SH surface wave propagating in a strain-gradient layered half-space. The dispersion equation of the SH surface wave is derived analytically. For the general case where both the surface layer and the half-space are strain-gradient elastic materials, the dispersion equation involves 10 material constants. The dispersion equation of the general case can degenerate to that of several special cases by dropping some material parameters. The existence regions of the dispersion curves are discussed in detail. The effects of strain-gradient elastic constants on the dispersion curves are examined. It is seen that the features of SH surface waves in strain-gradient elastic materials are much richer than those in classical elastic materials. Ministry of Education (MOE) The authors would like to thank the financial support from Singapore Ministry of Education Academic Research Fund Tier 1 (RG185/18). Jianmin Long also acknowledges the support from the National Natural Science Foundation of China (11702081) and the Fundamental Research Funds for the Central Universities, Hohai University (2019B08714).