Design charts for the local buckling analysis of integrally web-stiffened panels with filleted junctions subjected to uniaxial compressive loads: Fid-Bau Portal

Design charts for the local buckling analysis of integrally web-stiffened panels with filleted junctions subjected to uniaxial compressive loads

Garcia, Fernando Gonçalves / Ramos, Roberto Jr

Abstract

Abstract In this work, parametric finite element models are used to generate new design charts that provide the local buckling coefficient ( $k_{s l}$ ) of integrally web-stiffened panels (ISPs) subjected to uniaxial compressive loads, including the fillet radius effect. The numerical results from linear buckling analyses of hundreds of different panel geometries are presented in terms of four non-dimensional parameters: $t_{w} / t_{s}$ , $b_{w} / b_{s}$ , $t_{s} / b_{s}$ and $R / b_{w f}$ , whereby the latter represents the effect of the fillet radius on $k_{s l}$ . An extensive survey based on ISPs geometries used in different types of aircraft wings was conducted to define the ranges of these four ratios. Within each range, discrete values of the four ratios were chosen and randomly combined to enable the construction of the finite element models used to obtain the new $k_{s l}$ curves. The proposed finite element modeling was validated by comparing the results with numerical and experimental results from the literature, showing a good agreement. Compared to non-filleted ISPs results, it is shown that the local buckling stresses of filleted ISPs may be significantly increased, allowing designers to optimize different ISPs geometries.

Highlights • Local buckling coefficients of integrally stiffened panels with filleted junctions are presented in tabular form. • Results are presented in non-dimensional quantities, allowing the use for different panel geometries. • Results can be easily implemented in numerical programs to provide local buckling stresses for different geometries. • Finite element results were compared with other numerical and experimental results showing a good agreement. • Geometries considered in this work are based on wing upper panels found in commercial aircraft of large and medium sizes.