Dispersive behavior of high frequency Rayleigh waves propagating on an elastic half space  

作　　者：Ning Jia Zhilong Peng Jianjun Li Yin Yao Shaohua Chen 

机构地区：[1]Institute of Advanced Structure Technology,Beijing Institute of Technology,Beijing 100081,China [2]Beijing Key Laboratory of Lightweight Multi-Functional Composite Materials and Structures,Beijing Institute of Technology,Beijing 100081,China [3]School of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China

出　　处：《Acta Mechanica Sinica》2021年第4期562-569,I0001,共9页力学学报（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(Grants 11532013,11872114,11772333,and 12002033);the Project of State Key Laboratory of Explosion Science and Technology(Grant ZDKT17-02).

摘　　要：When the wavelength of Rayleigh wave is comparable with nanometers,Rayleigh wave will become dispersive.Such an interesting phenomenon cannot be predicted by the classical theory of elastodynamics.In order to reveal the internal mechanism and influencing factors of the dispersion,a model of Rayleigh wave propagating on an elastic half space is established and analyzed by a new theory of surface elastodynamics,in which the surface effect characterized by both the surface energy density and surface inertia is introduced.Two intrinsic nano-length scales,including the ratio of bulk surface energy density to bulk shear modulus and the ratio of surface mass density to bulk mass density,are achieved.It is found that when the wavelength of Rayleigh wave is comparable with the two intrinsic nano-lengths,the surface effect becomes significant.As a result,dispersion of Rayleigh wave happens and even two Rayleigh waves with different wave speeds may appear.Furthermore,it is found that the effect of surface energy density would enhance the wave speed,while that of surface inertia would reduce it.With the increase of wavelength,both effects gradually disappear and the Rayleigh wave speed degenerates to the classical one.The results of this paper are not only helpful to understand the dispersive mechanism of elastic waves,but also helpful for the fine design and measurement of nanowave devices.

关 键 词：Rayleigh wave High frequency DISPERSION ELASTODYNAMICS Surface effect 

分 类 号：O347.41[理学—固体力学] O436.3[理学—力学]