Functionally graded Timoshenko beams with elastically-restrained edge supports: thermal buckling analysis via stokes’ transformation technique

The present study investigates buckling in functionally graded material (FGM) beams when exposed to a temperature rise. The proposed FGM beams have arbitrary edge supports that are modeled by rotational and translational springs. The mechanical properties are assumed to vary continuously across the thickness direction according to a simple four-parameter power law. To obtain the critical value of temperature, the governing equilibrium equations are extracted based on Timoshenko beam theory, using the assumption of Von-Karman nonlinearity for the physical neutral surface concept. The equations are further solved by Fourier series expansion via Stokes’ transformation technique. Numerical examples are provided to demonstrate the accuracy and reliability of the proposed method. The influence of two models of metal-ceramic distribution across the thickness (symmetrical and unsymmetrical ones) on the response of the beam in thermal buckling of FG beam is investigated. It is observed that, the critical buckling temperature rises more for symmetrical model of FGM beam with respected to unsymmetrical one. Also, increasing the translational and rotational spring coefficient makes the beam stiffer; consequently, the critical buckling temperature is increased.

Thermal buckling, Timoshenko beam theory, Functionally graded material, Stokes’ transformation