Three-dimensional thermomechanical buckling of functionally graded materials

Three-dimensional thermomechanical buckling analysis is discussed for functionally graded materials. Material properties are varied continuously in the thickness direction according to a simple power-law distribution. The three-dimensional finite element model is adopted using an 18-node solid element and the assumed-strain mixed formulation is used to prevent locking as well as to maintain kinematic stability for thin structures. The thermal buckling behavior under time-dependent temperature rise is compared with that under time-independent temperature rise. In time-dependent temperature distribution, temperature at each node is obtained by solving the thermomechanical equations and the Crank-Nicolson method is used for a time discretization. In the case of time-independent temperature distribution, thermal buckling is investigated under uniform, linear, and sinusoidal temperature rise. Numerical results are compared with those of previous works. In addition, the changes of critical buckling temperature due to temperature field, volume fraction distributions, and system geometric parameters are studied.