Thermo-Elastic Column Buckling of Tapered Nanowires with Axially Varying Material Properties: A Critical Study on the Roles of Shear and Surface Energy

摘要

At the nanoscale, shear and surface energy play important roles in mechanical behavior of nanostructures, and therefore, such effects should be appropriately considered in the corresponding structural modeling. Herein, surface energy-based Euler-Bernoulli, Timoshenko, and higher-order beam theories are implemented to study buckling of thermally affected tapered nanowires with axial variation of materials. The governing equations associated with thermo-elastic buckling of nanowires are derived for an arbitrary variation of material properties of both bulk and surface layer across the length of nanostructure. In the lack of analytical solution, reproducing kernel particle method is adopted and the critical buckling load is evaluated. The effects of temperature gradient, slenderness ratio, power-law index of the material and geometry of the nanowire, radius, as well as transverse and rotational stiffness of the surrounding elastic medium on the buckling behavior of the nanowire are investigated. The importance of consideration of both surface energy and shear deformation effects on the obtained results is also highlighted. This work could be taken into account as a preliminary research in examining buckling of more complex nanosystems such as vertically aligned nanowires with arbitrary material's distribution and cross section.