Keywords: finite element analysis, geometric nonlinearity, thermal buckling, thin-walled beam, porous FG material, temperature distribution, large rotations.

This study presents a numerical model for predicting the thermal buckling behaviour of thin-walled porous functionally graded beams. A geometric nonlinear algorithm, utilizing a 1D numerical model with a spatial beam finite element, is employed. Small strains are defined using the Green-Lagrange tensor. The finite element model is developed based on Euler-Bernoulli theory for bending and Vlasov theory for torsion. Nonlinear analysis is conducted using the updated Lagrangian incremental formulation and the principle of virtual work. The displacement field accounts for large rotations and torsion with warping. Material properties are assumed to vary continuously through the wall thickness, following a power-law distribution. The proposed beam model analyzes buckling under uniform, linear, and nonlinear temperature distributions across the thickness of the cross-sectional walls, while also considering the temperature-dependent mechanical material properties. Numerical results explore critical buckling temperatures and post-buckling behaviour for various thin-walled sections, with different configurations including boundary conditions, geometry, FG skin-core-skin ratios, and power-law indices. Numerical results investigate critical buckling temperatures and post-buckling behaviour for various thin-walled beam cross-sections, boundary conditions, geometry, FG skin-core-skin ratios, and power-law exponent. The algorithm is validated with commercial software 2D finite element results. An acceptable agreement is recognized comparing to those obtained by shell models.

download the full-text of this paper (PDF, 10 pages, 553 Kb)

go to the previous paper
go to the next paper
return to the table of contents
return to the volume description