Thermal buckling, vibration and transient response of rotating GNPs-reinforced porous microbeams in thermal environment

Abstract

A comprehensive dynamic model for thermal buckling, elastic vibration and transient response analysis of rotating nano-composite porous metal-matrix microbeams reinforced with graphene nanoplatelets (GNPs) under a uniform thermal gradient is proposed. Various pore distribution patterns are considered together with different GNPs dispersion rules according to the specific functions. The extended rule of mixture and Halpin-Tsai micromechanics model are employed to evaluate the effective material properties of the nanocomposites. Based on the modified couple stress theory and the improved third-order shear deformation theory, the dynamic equations of the rotating microbeam are established by the Lagrange’s equation. The Chebyshev-based Galerkin method is adopted to discretize these equations, which are then solved by the complex modal analysis and Runge-Kutta-Merson method. Convergence study and comparisons with previous literature are conducted for validation of the present method. A parametric study performed analyzes the effects of angular velocity, thickness-to-length scale parameter ratio, porosity coefficient, weight fraction and geometry of GNPs together with distribution patterns of GNPs and pore on the critical buckling temperature rise, fundamental frequency and time-dependent response of the rotating nanocomposite microbeams. The results reveal significant effects of these parameters on the relevant mechanical behaviors, some of which are even contrary to expectations. Therefore, it is necessary to further study this kind of rotating nanocomposite structures for the optimal design.