A-Basis and B-Basis buckling allowables for an aircraft composite wing

Abstract

Buckling is a critical failure mode for aircraft composite panels. Therefore, determining the critical buckling load is essential for properly modeling. To optimize composite laminate structures, it is important to know the strength of the laminate, which can be obtained through statistical analyses based on test data. The resultant strength value is known as a design allowable. This paper aims to establish an approach to evaluate two types of statistically determined buckling allowables, A-Basis and B-Basis, for an aircraft composite wing. In this study, a finite element model of a composite semi-wing was used to perform linear buckling simulations. Six input parameters were initially selected as relevant to affect the buckling strength of the semi-wing: four material properties and two geometric parameters. A set of Monte Carlo simulations was conducted varying these parameters of interest, followed by a global sensitivity analysis using Sobol indices to identify the influence of each one, individually (first-order) and in pairs (second-order). A surrogate model based on artificial neural networks was then trained using data from the Monte Carlo simulations. Finally, this surrogate model was used to define the A-Basis and B-Basis allowables for a critical loading case.