Struct Multidisc Optim DOI 10.1007/s00158-010-0612-9 INDUSTRIAL APPLICATION Development of a framework for truss-braced wing conceptual MDO Ohad Gur · Manav Bhatia · William H. Mason · Joseph A. Schetz · Rakesh K. Kapania · Taewoo Nam Received: 3 June 2010 / Revised: 18 October 2010 / Accepted: 10 December 2010 c  Springer-Verlag (outside the USA) 2011 Abstract The paper describes the development of a mul- tidisciplinary design optimization framework for con- ceptual design of truss-braced wing configurations. This unconventional configuration requires specialized analysis tools supported by a modular and flexible framework to accommodate different configurations. While the previous framework developed at Virginia Tech was a monolithic Fortran-77 code, the need for more flexibility for com- plex truss-braced wing configurations was addressed by the development of this new framework, which is based on Phoenix Integration ModelCenter TM environment. The framework uses updated structural and aerodynamic de- sign modules that enable a more general geometry defini- tion. The new framework, thus, provides a foundation for future design concepts, especially multi-member truss- braced wing configurations. The fuel saving potential of these truss-braced wing configurations is presented by com- paring different truss designs with gradually increased level of complexity. Keywords MDO · Truss-Braced Wing · Framework · Design environment The paper was presented as AIAA Paper 2010-2754 in the 6th AIAA Multidisciplinary Design Optimization Specialist Conference, April 12–15, 2010, Orlando, Florida. O. Gur (B ) · M. Bhatia · W. H. Mason · J. A. Schetz · R. K. Kapania Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0203, USA e-mail: ohadg@vt.edu T. Nam Georgia Institute of Technology, Atlanta, GA 30332-0150, USA Abbreviations (·) break break section (·) cr cruise (·) jury jury (·) root root section (·) strut main strut (·) tip tip section (·) wing wing Nomenclature A cross-sectional area A C load-bearing cross-sectional area b wing span C L α vehicle lift coefficient slope c chord c avg average chord c fuel fuel-tank chord c st wing-box chord D drag d nacelle , l nacelle diameter and length of the engine nacelle, respectively E 1 , E 2 Young’s Modulus of the wing skin and spar webs, respectively (EI) xx ,(EI) zz bending stiffness F s shear force (GJ) torsion stiffness G 1 , G 2 Shear Modulus of the wing skin and spar webs, respectively g acceleration of gravity K g gust alleviation factor L lift M Mach number m vehicle mass