Buckling of Stiffened Panels: An Improved Linearized Approach Compared to Nonlinear Collapse Analysis

This paper deals with the buckling assessment of stiffened panels, typical of ship and offshore structures. In particular, rather slender structures, involving very thin plates and stiffeners with limited cross section, are considered. In order to limit the computational burden of a fully nonlinear progressive collapse analysis but, at the same time, to retain some benefits of a numerical finite element model assessment, an improved linearized buckling procedure is proposed in this work. The idea is to linearize the computation in a suitable point based on the design load of the structure, so that the results of a linearized buckling analysis are more informative in practice. Results are assessed with nonlinear collapse analyses, comprehensively considering various loading cases. Eventually, a hands-on buckling assessment procedure is suggested, which can be implemented in rules and design process if adequately validated by a suitable number of test cases and, possibly, experimental data.

Component-Wise Models for the Accurate Dynamic and Buckling Analysis of Composite Wing Structures

In the present work, a higher-order beam model able to characterize correctly the three-dimensional strain and stress fields with minimum computational efforts is proposed. One-dimensional models are formulated by employing the Carrera Unified Formulation (CUF), according to which the generic 3D displacement field is expressed as the expansion of the primary mechanical variables. In such a way, by employing a recursive index notation, the governing equations and the related finite element arrays of arbitrarily refined beam models can be written in a very compact and unified manner. A Component-Wise (CW) approach is developed in this work by using Lagrange polynomials as expanding cross-sectional functions. By using the principle of virtual work and CUF, free vibration and linearized buckling analyses of composite aerospace structures are investigated. The capabilities of the proposed methodology and the advantages over the classical methods and state-of-the-art tools are widely demonstrated by numerical results.