AE220: Aerospace Structural Mechanics
Introduction:
Credits: 8 (3L-1T-0P-8C)
Prerequisites: AE209 (Solid Mechanics)
Course Contents: Introduction: semi-monocoque aerospace structures - Loads and Design considerations; construction concepts, layout, nomenclature and structural function of parts, strength vs stiffness based design.
Torsion of non-circular prismatic beams: importance of warping; St. Venant or Prandtl’s formulation; Membrane analogy and its application to narrow rectangular cross-section.
General formulation of Thin-Walled Beam (TWB) Theory: Cartesian and midline systems, CSRD & thin-wall assumptions, general expressions for dominant displacement, strain and stress fields, equilibrium equations in midline system, stress resultants and general boundary conditions.
Torsion and Bending of TWBs: Torsion of single and multi cell closed sections - Bredt-Batho theory, shear flow, torsion constant, free warping calculation, concept of center of twist, torsional equilibrium equation and boundary conditions. Torsion of open TWBs without warp restraint, primary & secondary warping, St. Venant torsion constant. Uncoupled bending of open, closed, single cell, multi-cell TWBs - axial stress, shear flow, shear centre, displacement analysis. Torsion of open section TWBs with primary warp restraint - concept and theory of torsion bending, torsion bending constant, secondary warping restraint. Unsymmetric bending and coupled bending torsion analysis.
Buckling of TWBs: Concept of structural instability, flexural buckling analysis, bending of beams under combined axial and lateral loads, short column and inelastic buckling. Pure torsional buckling and coupled flexural-torsional buckling of open TWBs. Introduction to the concept of buckling of plates, local buckling of TWBs. Introduction to buckling and post-buckling of stiffened skin panels, ultimate load carrying capacity of a typical semimonocoque TW box-section. Introduction to tension-field beams.
Text Books:
- Megson, T. H. G., Aircraft Structures for Engineering Students, Butterworth-Heinemann, 4th Ed., 2007. (Available in Library)
Peery, D. J., Aircraft Structures, McGraw-Hill Education, 1st Ed., 1950 (Available in library)
- Donaldson, B. K., Analysis of Aircraft Structures (Cambridge Aerospace Series), 2nd Ed., Cambridge University Press, 2008
- Sun, C. T., Mechanics of Aircraft Structures, Wiley-Interscience, 1998
- Bruhn, E. F., Analysis and Design of Flight Vehicle Structures, Jacobs Pub., 1973
Niu, M., Airframe Stress Analysis & Sizing, Adaso Adastra Engineering Center, 1998
- Cutler, J. and Liber, J., Understanding Aircraft Structures, Wiley Blackwell, 4th Ed., 2006
Internet Resources
Interesting Links
Video shows the testing of a Boeing 787 Dreamliner wing.
Video shows the testing of Boeing 777 wing.
Wing box, spars, ribs, longerons.