Buckling of Hybrid Composite Carbon/Epoxy/Aluminum Plates with Cutouts

Abstract

Structural instability becomes an important concern in the composite plate safe and reliable design. In this research, a resistance analysis is carried out on plates made of hybrid composite material with and without elliptical cutouts using the finite element method. The carbon/epoxy/aluminum laminated plates are arranged in the following ordered manner [Al/(θ/-θ)/Al]. The hybrid plate resistance to buckling submitted to uniaxial compression is highlighted. Results indicate that given a structural geometry, boundary and loading condition and stacking sequence, the buckling resistance of such plates is strongly influenced by the ply orientation, the anisotropy ratio, and the cutout presence, position and size. The critical load reduction is found to decrease linearly with the decrease of the geometric ratio a/b. When b=8a, the reduction factor N* increased from 1.8% to 7% when φ=90ο and φ=0ο respectively regardless of the ply orientation. Maximum reduction of the buckling critical load is important when the elliptical cutout is located in the middle of the plate. Regardless of the declination of the elliptical cutout, maximum reduction of the critical buckling stress is obtained when the ratio E2/E1=1.