Robust design and optimization of composite stiffened panels in post-buckling

Abstract

Multilevel optimization including progressive failure analysis and robust design optimization for composite stiffened panels, in which the ultimate load that a post-buckled panel can bear is maximized for a chosen weight, is presented for the first time. This method is a novel robust multiobjective approach for structural sizing of composite stiffened panels at different design stages. The approach is integrated at two design stages labelled as preliminary design and detailed design. The robust multilevel design methodology integrates the structural sizing to minimize the variance of the structural response. This method improves the product quality by minimizing variability of the output performance function. This innovative approach simulates the sequence of actions taken during design and structural sizing in industry where the manufacture of the final product uses an industrial organization that goes from the material characterization up to trade constraints, through preliminary analysis and detailed design. The developed methodology is validated with an example in which the initial architecture is conceived at the preliminary design stage by generating a Pareto front for competing objectives that is used to choose a design with a required weight. Then a robust solution is sought in the neighbourhood of this solution to finally find the layup for the panel capable of bearing the highest load for the given geometry and boundary conditions.

Reliability-based design optimization of composite stiffened panels in post-buckling regime

“…In Bacarreza et al (2015) the problem was initially defined as a multi-objective optimization aimed to maximize both the reaction force Rf and the internal energy En, subject to the fulfillment of a certain value of the reaction force Rf =655.0 kN.…”

“…In order to predict the collapse load properly, post-buckling and progressive damage analyses are considered as an intrinsic part of the problem. In this study the reference panel employed is obtained from the preliminary design optimization phase performed in Bacarreza et al (2015), where the number of plies, number of stiffeners and geometry dimensions were considered as design variables, being the targets to minimize the mass and the Tsai-Wu index and maximize the reaction force.…”

“…Some strategies tend to split the optimization process in several phases because including all that information in a single optimization problem may make it ungovernable. For instance, the optimization strategy proposed in Bacarreza et al (2015) divides the optimization process in two stages: a preliminary design optimization and a detailed design optimization.…”

“…It is important to highlight that the reference panel employed comes from the preliminary design optimization performed in Bacarreza et al (2015). Therefore the number of plies, thicknesses, number of stiffeners and geometry dimensions of the panel are optimum values already obtained from a previous optimization process aimed to minimize the mass of the structure.…”

Analysis and Design for the Moderately Deep Postbuckling Behavior of Composite Plates

“…To overcome the computational problems, an alternative strategy of constructing approximate models (also known as surrogate models or response surface models) to replace the expensive FEM simulation in the optimization process has been extensively used in recent years. A number of methods have been successfully applied to build the global/local approximation models for postbuckling anal-ysis of composite structures, for example, the polynomial regression function [8], Articial Neural Networks [9,10], Radial Basis Functions [10] and Kriging method [9]. The minimum weight design of composite structural components (stiened panels and shells) considering their postbuckling response was carried out using these tools or approximate models.…”