多孔弹性层的刚性边界对扭转表面波传播的影响

Effect of Rigid Boundary on Propagation of Torsional Surface Waves in Porous Elastic Layer

根据介质的力学性能,正如Cowin及Nunziato一样,导出多孔弹性层覆盖在多孔弹性半空间上时,研究其刚性边界对扭转表面波传播的影响.导出了速度方程并对其结果进行了讨论.发现介质中可能存在两类扭转表面波阵面,而Dey等(Tamkang Journal of Science and Engineering,2003,6(4):241-249.)给出的没有刚性边界面时,存在3类扭转表面波阵面.研究还揭示,多孔弹性层中Love波也可能随同扭转表面波一起存在.值得注意的是,刚性边界面多孔弹性层中Love波的相速度,不同于自由边界面多孔弹性层中的相速度.实际观察到扭转波的色散性,以及速度随着振荡频率的增大而减小.

The effect of rigid boundary on the propagation of torsional surface waves in a porous elastic layer over a porous elastic half space was presented using the mechanics of the medium as derived by Cowin and Nunziato.The velocity equation was derived and the results were discussed.It is observed that there may be two torsional surface wave fronts in the medium whereas there exists three wave fronts of torsional surface waves in the absence of rigid boundary plane given by Dey et al（Tamkang Journal of Science and Engineering,2003,6（4）： 241-249.）.The results also reveals that in the porous layer,the Love wave is also available along with the torsional surface waves.It is remarkable that phase speed of Love wave in a porous layer with rigid surface is different from that in a porous layer with a free surface.The torsional waves are observed to be dispersive in nature,and the velocity decreases as the frequency of oscillation increases.