1995 Catalog Data: 14:650:458: Aerospace Structures.

Prerequisite: 14:650:291

Load factors, stresses and deformations in thin-walled members, shear center, torsion of single-cell and multicell structures, analysis of aircraft components.

Textbook:   Aircraft Structures, 2nd Edition, D. Peery and J. Azar, McGraw Hill, 1982

Reference:

1. Analysis and Design of Flight Vehicle Structures, E. Bruhn, Jacobs Publishing, 1973.
2. Aircraft Structures for Engineering Students, T.H.G.Megson, Edward Arnold, 1992.
3. Theory and Analysis of Flight Structures, R.M. Rivello, McGraw Hill, 1969.

Coordinator: Dr. Rashad A. Elbeshbeshy, Adjunct Professor of Mechanical Engineering

Goals:

The objective of the course is to introduce the student to advanced concepts in solid mechanics and to extend these ideas to the analysis of aircraft components, particularly the analysis of thin-walled members in shear and torsion. Also, energy and variational methods are introduced. Students learn about aerospace design by a series of computer projects.

Prerequisites by topic:

1. Stress-strain relationship, Mohr circle.
2. Beam and torsion theories.
   

Topics:

1. Introduction, historical background, loads on aircraft, limit loads and G-factors, factor of safety and margin of safety , design considerations. (1 lecture)
2. Flight vehicle materials and their properties, fatigue consideration, weight optimization and sandwich construction.(2).
3. Shear flow in thin webs, shear center, shear flow in closed in boxed beam, non- symmetrical bending(2).
4. Torsion of non-circular beams, torsion in thin-walled section and multicell structures.(1)
5. Instability of structural members; gross buckling of columns, local buckling of composite shapes, buckling strength of flat sheets panels, crippling strength of composite shapes and stiffened panels. Applications to wing and fuselage construction, cutout in boxed beams and stress concentration factors.(3).
6. Introduction to advanced beam theory; equilibrium, compatibility and stress/strain relationship, Airy stress function formulation. Application to simple beams. and thermal stresses. (2)
7. Virtual work , strain energy an complimentary strain energy, unit load method, Castigliano's theory, Ralyleigh Ritz method. (2).
8. Introduction to numerical technique, finite element method vs. finite difference method, structural idealization, design considerations. (2)
9. Hourly examinations and review.
10. Final examination.
    

Homework: Usually six to seven homework sets are assigned.

Design Projects:

Two design projects are discussed and interactively attacked. In the first, students are required to perform a shear flow analysis on a multicell structure in torsion. They are required to add new webs to the structure, and to vary the thicknesses of the webs and of the structure to minimize the associated stresses.

In the second project, students are required to develop an idealized structure which is subject to both torsional and shear loading. The project then requires the students to vary the locations of the longitudinals and to analyze the resulting stresses, so that a desirable distribution of longitudinals along the cross- section can be designed.

ABET Category Content (as estimated by faculty member who prepared this course description):

Engineering Science 50% or 1.5 Credits

Engineering Design 50% or 1.5 Credits.