Stress waves in thick porous graphene-reinforced cylinders under thermal gradient environments

Abstract

In this paper, the propagation of stress waves in thick porous graphene-reinforced cylinders (TPGRCs) is investigated using a meshless solution based on an axisymmetric model and moving least squares (MLSs) interpolation functions. The cylinders are assumed under a steady state thermal gradient effect along with an initial deflection response obtained from the static solution of the same cylinder subjected to a static internal pressure. To improve the design of such TPGRCs, functionally graded (FG) profiles are considered for the distribution of graphene nanofillers along their radial direction. Moreover, pores are non-uniformly embedded inside the cylinders to decrease the weight of TPGRCs. The material properties of porous and nanocomposite materials are calculated as functions of temperature using a closed cell model and a modified Halpin-Tsai (HS) technique, respectively. Considering structural damping for the system, the influences of embedding porosity, the temperature of each surface, reinforcing with graphene and the thickness of cylinder on the stress wave responses of TPGRCs have been investigated. The results reveal that the increase of porosity volume inside TPGRCs significantly increases the amplitudes and stationary time of deflections; however, it reduces the values of stationary deflections and stresses, along with the reduction of propagation speeds.