Date of Award


Document Type

Thesis - Open Access

Degree Name

Master of Aerospace Engineering


Aerospace Engineering

Committee Chair

Dr. James Ladesic

Committee Member

Dr. Frank Radosta

Committee Member

Dr. Frederique Drullion


Classical methods for buckling assessment of aircraft panels reinforced by bulb-stiffened flanges differ regarding symmetric versus asymmetric cross-sections. The present research addresses a number of classical derivations of methods with a focus on the work of Dwight Windenburg as published in "The Elastic Stability of Tee Stiffeners" and the expansion of his work to asymmetric sections by E. F Bruhn in Analysis and Design of Aerospace Vehicle Structures. Vagueness in the relevance of geometric symmetry of the bulb exists between Windenburg's plate theory approach, and the accepted industry standard applications defined in the methods of Bruhn. The results presented trace the bibliographic history of sizing bulb-stiffeners to achieve the highest critical stress obtainable by the web, and verify the two sizing procedures theoretically and using Finite Element Analysis software. The results suggest that the theoretical approach presented by Windenburg is correct as stated; however the FEA results suggest that the claim made by Bruhn's and Windenburg's sizing process is inadequate.