Journal of Theoretical
and Applied Mechanics

56, 3, pp. 701-712, Warsaw 2018
DOI: 10.15632/jtam-pl.56.3.701

Mechanical buckling of functionally graded polyethylene/clay nanocomposites columns based on the Engesser-Timoshenko beam theory

Mohammad Hossein Yas, Mahdi Karami Khorramabadi
This paper deals with mechanical buckling of polyethylene/clay nanocomposite beams of
functionally graded and uniformly distributed of nanoclay subjected to axial compressive
load with simply supported conditions at both ends. The Young moduli of functionally
graded and uniformly distributed nanocomposites are calculated using a genetic algorithm
procedure and then compared with experimental results. The formulation is modified to
include the effect of nanoparticles weight fractions in the calculation of the Young modulus
for uniform distribution. Also, it is modified to take into account the Young modulus as
a function of the thickness coordinate. The displacement field of the beam is assumed ba-
sed on the Engesser-Timoshenko beam theory. Applying the Hamilton principle, governing
equations are derived. The influence of nanoparticles on the buckling load of the beam is
presented. To investigate the accuracy of the present analysis, a compression study with the
experimental results is carried out.
Keywords: mechanical buckling, functionally graded nanocomposite, montmorillonite, gene- tic algorithm theory


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