Assessment of CUF-Based Variable-Section 1D Finite Elements for the Nonlinear Analysis of a Wingbox Structure
Francesco Mario Antonio MITROTTA, Antonio Paolo FONTANELLA, Maria CINEFRA, Rauno CAVALLARO
Abstract. The integration of postbuckling behavior into aeroelastic optimization frameworks faces a critical barrier in the computational cost of nonlinear finite element analyses with traditional shell-based wingbox models. This study investigates whether variable-section 1D finite elements based on the Carrera Unified Formulation (CUF) can replicate the nonlinear response of wingbox structures with reduced computational cost. Nonlinear analyses of the Simple Transonic Wing benchmark are performed using MSC Nastran shell elements and two CUF models with different mesh refinements. While the CUF models achieve comparable or better computational efficiency, the approaches predict substantially different onset points for geometric nonlinearity: the Nastran model exhibits softening behavior at the linear buckling load of 133 kN, whereas the CUF models maintain nearly linear response until approximately 264–272 kN. Importantly, the close agreement between the two CUF mesh refinements demonstrates that this discrepancy cannot be attributed to insufficient CUF discretization. These findings raise a critical question about the minimum fidelity required to accurately capture global nonlinear postbuckling behavior, whose answer is essential for including nonlinear structural stability analysis in aeroelastic optimization.
Keywords
Carrera Unified Formulation, Finite Element Analysis, Nonlinear Analysis, Wingbox Structure
Published online 7/20/2026, 6 pages
Copyright © 2026 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA
Citation: Francesco Mario Antonio MITROTTA, Antonio Paolo FONTANELLA, Maria CINEFRA, Rauno CAVALLARO, Assessment of CUF-Based Variable-Section 1D Finite Elements for the Nonlinear Analysis of a Wingbox Structure, Materials Research Proceedings, Vol. 69, pp 1416-1421, 2026
DOI: https://doi.org/10.21741/9781644904251-248
The article was published as article 248 of the book CEAS – AIDAA Conference 2025
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
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