Post buckling behavior of stiffened curved panel with cut outs using arc length method

Abstract

In structural engineering applications, the stiffened panel plays a key role in reducing weight of the whole structure. The structural design of the aircraft mainly focuses achieving higher strength to weight ratio. Inclusion of the thin-walled structures considered to be the best preference for attaining higher strength to weight ratio. In contrary the inappropriate design of the thin-walled structures lead to failure due to buckling. In order to improve buckling strength thin walled structures with/without curvature and cut-outs, stiffeners of different shapes, geometrical conditions and varying numbers are employed. In this research work, numerical investigations were carried out on 108 models of the stiffened panel using finite element based code Abaqus v6.14. Stiffened panels with various panel radius, plate thickness, stiffener thickness and stiffener types are considered under uniaxial compression load. Prediction of the critical buckling load, with mode shape for the first buckling modes of the stiffened panel, was obtained by the Linear Eigen Value Extraction method. The failure load of the stiffened curved panel after buckling was predicted by using STATIC Riks (arc length) method. Initial geometrical imperfections and nonlinearities of the materials were considered for better results. The methodology used in this study has good agreement with reference to experimental studies. The numerical results obtained are qualitatively presented using displacement contours of the buckling and post-buckling behaviours and the quantitative presentation of important parameters such as ultimate load is carried out using load- shortening plots. newline