Some Discussions On Interfacial Mechanical Properties Of Solid Material

In order to illustrate the interfacial mechanical properties of solid materials more comprehensively,according to the scale of the research object,our paper will study the conduction behavior of mechanical waves in the very rough interfacial junction area between two solid media,and re-examine the G-M surface elasticity theory from the perspective of density functional theory(OFDFT),respectively.On one hand,we first use the asymptotic homogenization technique to study the conduction behavior of mechanical waves in the very rough interface between two solid media.And an equivalent gradient interface layer is obtained to replace the extremely rough interface domain.Then,the investigation of harmonic wave propagation in the equivalent layer is analyzed by using the transfer matrix method.The results show that,the rough interface exhibits not only the classical characteristics as well known,but also an interesting dissipation phenomenon is also exhibited.Finally,the propagation of waves in the hierarchical rough interfaces is discussed through numerical examples.On the other hand,the traditional G-M theory of surface elasticity is proved to be correct by introducing the "boundary layer" to describe the solid boundary region based on the density functional theory(OFDFT).Our research also shows the following conclusions: Firstly,based on the theoretical model of OFDFT,we can deduce the explicit expression of G-M surface elasticity theory;secondly,the expression of surface energy density can accurately describe the competition effect of electron density and electrostatic potential on solid surface along the normal gradient.Thirdly,the model we built naturally expresses the negative linear relationship between the elastic stiffness of the material surface and its overall size.Since our theory is based on the model of OFDFT under arbitrary boundary conditions of electron density,electrostatic potential and external load,it may also be used to study the electromechanical coupling of surface effects of nanomaterial.