Buckling of multiple delaminated beams. (English) Zbl 0932.74030

Summary: Delaminations weaken a laminated beam, which then fails prematurely under in-plane compression. Here we perform an exact buckling analysis for beams with double delaminations. Novel adoption of two coordinates and choice of slope as the unknown function reduce the buckling equations to solvable geometric equations. We analyze the complex buckling behavior for different sizes and depths of delaminations, and identify “free mode” and “constrained mode” of buckling. Both global and local buckling occurs, depending upon the slenderness ratios of the delaminations. In addition, we derive upper and lower bounds on buckling loads by assuming totally “constrained” and totally “free” deformation for the delaminated beam. These bounds are easy to compute and can provide useful approximations.


74G60 Bifurcation and buckling
74K10 Rods (beams, columns, shafts, arches, rings, etc.)
74R99 Fracture and damage
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