ABSTRACT
In this chapter, the focus will be on the effects of the existence of porosities on the mechanical behaviors of nanosize beams and plates subjected to propagation of elastic waves. The existence of porosity in the material will be modeled using two different porosity-dependent homogenization methods. In the first one, the effects of porosity on the material properties of the composite will be included by defining a volume fraction for the porosities and using the simple form of the rule of the mixture. In the second one, it will be assumed that existence of porosities can produce a coupling between the stiffness of the porous material and the density of both porous and nonporous materials. It will be shown that the second type can justify the existence of porosities in the material better. Using these two methods, the wave propagation curves of composite nanostructures will be studied to show the impact of porosity on the propagation curves from both qualitative and quantitative points of view.
