Buckling of stiffened composite panels with stringer terminations

Abstract

A meshless approach is developed and used to predict buckling of discretely assembled multibay composite panels made from skin and stiffeners. The effect of eccentricity is included in the formulation. Particular emphasis is given to stringer run-outs within a stiffened panel, where abrupt eccentricity can trigger very large transverse displacements of the skin in front of the run-out tip. The model is obtained by combining von Karman's formulation for moderately large deflections in plates with an extended Timoshenko approach for small initial perturbations. Solutions are calculated by means of a Rayleigh-Ritz approach in conjunction with a Galerkin technique. Hilbert's orthogonal eigenfunctions are employed to obtain a generalized Fourier series expansion of the variables of interest. Limits of applicability, convergence of results and further potential exploitations are discussed. Numerical results obtained are compared with finite element analysis.