Thermal buckling of rotating pre-twisted functionally graded microbeams with temperature-dependent material properties

Abstract

As a first endeavor, the thermal buckling of rotating pre-twisted functionally graded (FG) microbeams with temperature-dependent material properties is studied based on the modified strain gradient theory in conjunction with the first-order shear deformation theory of beams. The adjacent equilibrium criterion and Chebyshev–Ritz method are employed to derive the nonlinear algebraic eigenvalue equations governing the thermal buckling behavior of the microbeams, which are solved iteratively. The fast rate of convergence and accuracy of the method are numerically demonstrated. Then, the effects of the twist angle, rate of twist angle (as an important geometrical design parameter), material length scale parameter, material gradient index and angular velocity on the thermal load-bearing capacity of rotating pre-twisted FG microbeams under different boundary conditions are studied. It is shown that by increasing the hub radius, the angular velocity and the length scale parameter, the thermal buckling load increases, but an increase of the material gradient index reduces the critical thermal buckling load. In addition, the formulation can be easily degenerated to those of large-scale rotating pre-twisted FG beams.