AO4102 Aircraft Structural Mechanics Syllabus:
AO4102 Aircraft Structural Mechanics Syllabus – Anna University PG Syllabus Regulation 2021
COURSE OBJECTIVES:
This course will enable the students
1. To gain important technical aspects on the theory of bending of structures.
2. To learn the key aspects of shear flow in open and closed sections.
3. To study the stability problems in structures with various modes of loading.
4. To analyse aircraft structural components under various forms of loading.
5. To have basic idea about the importance of flight envelope.
UNIT I BENDING OF BEAMS
Elementary theory of pure bending – Stresses in beams of symmetrical and unsymmetrical sections – Box beams – Generalized theory of bending – Methods of bending stress determination – Principal axes method – Neutral axis method – ‘k’ method – Deflection of unsymmetrical beams – Stresses in Composite Beams – Idealization of cross-section – Wing spar sizing
UNIT II SHEAR FLOW IN THIN-WALLED SECTION
General stress, strain and displacement relationships for open section thin-walled beams – Concept of shear flow – Shear flow in thin walled open sections – Determinations of the shear centre – Symmetrical and unsymmetrical cross-sections – Shear flow due to bending in open sections – Torsion of thin-walled open section members & determination of stresses – Design of thin-walled members
UNIT III SHEAR FLOW IN CLOSED SECTIONS
Shear flow in thin-walled closed sections – Symmetrical and unsymmetrical sections – Flexural shear flow in two flange, three flange and multi-flange box beams – Determinations of the shear centre – Bredt-Batho theory – Torsional shear flow in multi-cell tubes – Shear flow due to combined bending and torsion – Stress analysis of aircraft components – Tapered wing spar – Introduction to shear lag
UNIT IV STABILITY PROBLEMS
Stability problems of thin walled structures – Buckling of sheets under compression, shear, and combined loads – Plate buckling coefficient – Inelastic buckling of plates – Sheet-stiffener panels – Effective width – Failure stress in plates and stiffened panels – Crippling stress estimation – Local Buckling – Wagner beam theory – Experimental determination of critical load for a flat plate – Principles of stiffener/web construction
UNIT V ANALYSIS OF AIRCRAFT STRUCTURAL COMPONENTS
Aircraft Loads – Symmetric manoeuvre loads – Load factor determination – Inertia loads – Aerodynamic loads & Schrenk’s curve – The flight envelope – Shear force, bending moment and torque distribution along the span of the wing and fuselage – Structural parts of wing and fuselage and their functions – Analysis of rings and frames –– Introduction to aeroelasticity and shells.
TOTAL: 60 PERIODS
COURSE OUTCOMES:
At the end of this course, students will be able to
CO1: Apply the concept of normal stress variation in unsymmetrical sections subject to bending moments.
CO2: Find the shear flow variation in thin walled open sections with skin effective and ineffective in bending.
CO3: Evaluate the shear flow variation in single cell and multi-cell tubes subjected to shear and torque loads.
CO4: Analyse the behaviour of buckling of simply supported plates and also to know the effective width of sheet stringers combination.
CO5: Analyse and design structural members subject to compression.
REFERENCES:
1. Bruce. K. Donaldson, “Analysis of Aircraft Structures: An Introduction”, Cambridge University Press, 2nd edition, 2012.
2. Bruhn. EF, “ Analysis and Design of Flight Vehicle Structures”, Tristate Offset Co., 1980.
3. Megson, TMG, “Aircraft Structures for Engineering Students”, Elsevier, Aerospace Engineering, Series, 7th Edition, 2021.
4. Peery, DJ. And Azar, JJ, “Aircraft Structures”, 2nd Edition, McGraw-Hill, New York, 1993.
5. Rivello, R.M, “Theory and Analysis of Flight structures”, McGraw-Hill, N.Y., 1993.
6. Sun. CT, “Mechanics of Aircraft Structures”, Wiley publishers, 2nd edition, 2006.