Moishe Garfinkle                   Christopher Pastore
garfinkm@mail.drexel.edu        pastorec@philau.edu

(215) 235-5042                          (215) 951-2683

Executive Summary
Hitherto intrinsically-smart (passive) structures, particularly box-beams, could not be continuously-wound but rather required manual-layup of fabric sections, resulting in seams, potential regions of weakness in load-bearing applications. Such discontinuities severely limits the usefulness of intrinsically-smart structures in life-critical applications, particularly when serving as wing spars.
An intrinsically-smart box-beam fabricated by continuous-winding without discontinuities is described and aeronautical applications relating to wing and rotor stabilization suggested. Wings with heavy tip loads such as fuel, weapons or lift engines are subject to adverse pitch-twist coupling under harsh weather conditions or during severe maneuveres, as are high aspect-ratio wings of aircraft serving HALE missions. Wing spars with intrinsic beneficial twist-bend coupling can ameliorate these adverse effects.
The intrinsically-smart load-bearing box-beam architecture described herein can be fabricated by continuous-winding using conventional winding equipment and exhibits reversible twist-bend coupling. The proprietary continuous-winding architecture of the coupled beam was developed by M. Garfinkle, evaluated by C. Pastore and S. Greenhalgh, and analysed by C. Pastore, A. Bogdanovich and A. Birger.

1. Nomenclature
2. Fabrication of Coupled Box-Beams
3. Performance of Quasi-Unbalanced Box-Beams
4. Configurational Considerations
5. Application Considerations
6. Specific Application
7. Combined Techniques
8. Summary

For detailed information concerning the coupled spar
consult the webpage:
Moishe Garfinkle                   Christopher Pastore