Abstract:

Lightweight sandwich annular plates with honeycomb cores (HCCs) and carbon-nanotube-reinforced face sheets have been widely used in aerospace and energy structures where the high stiffness-to-weight ratio and the buckling reliability are required. In this paper, an integrated thermo-mechanical buckling model is presented for such plates resting on a radially graded modified Winkler-Pasternak (MWP) elastic foundation. The interlaminar shear deformation and the layerwise displacement continuity are accurately represented with the refined zigzag theory (RZT), while the carbon nanotube (CNT) agglomeration effects are considered with the Mori-Tanaka homogenization scheme. The governing equations are solved with the generalized differential quadrature method (GDQM). The results indicate that the CNT dispersion quality is more decisive than the CNT volume fraction, and the severe agglomeration reduces the critical buckling load by approximate 50%. A proper honeycomb design, particularly with a cell angle of approximate 30°, a wall thickness ratio within the range of 0.1 to 0.15, and a compact cell configuration, markedly enhances the structural stability. The radially graded foundation stiffness interaction increases the buckling capacity by 6%–15%, whereas temperatures of 300 K–400 K slightly reduce the capacity.

Key words: honeycomb core (HCC), carbon nanotube (CNT)-reinforced nanocomposite, refined zigzag theory (RZT), modified Winkler-Pasternak (MWP) foundation, buckling analysis