Module 1. Overview of Aircraft Structural Design and Manufacturing.pdf

AE641: Aircraft Structures 1 Module 1:Overview of Aircraft Structural Design and Manufacturing (Part 1) Presented by: John Gabriel G. Decena M.Eng Department of Aeronautics, FEATI University AE641: Aircraft Structures 1...

AE641: Aircraft Structures 1 Module 1:Overview of Aircraft Structural Design and Manufacturing (Part 1) Presented by: John Gabriel G. Decena M.Eng Department of Aeronautics, FEATI University AE641: Aircraft Structures 1 1–1  The module is divided into the following topics:  1.1 Major & Minor Structural members  1.2 Design Process  1.3 Planning & structural Weights  1.4 Engineers Responsibility  1.5 Production AE641: Aircraft Structures 1 1–2  At the end of the module the students should be able to:  Identify the different structural members and explain their functions.  Narrate the design process for aircraft in general.  Explain how are structural weight derived.  Discuss the responsibility of an engineer.  Narrate the production process for aircraft structures. AE641: Aircraft Structures 1 1–3  Overview We are all aware that there are many different categories of aircraft. Mainly: airplane, rotorcraft, glider and lighter than air aircraft. In this module our main focus will be on airplane since this are the most common type of aircraft. In addition, out of all the categories of aircraft, airplane experiences the most structural stresses due the maneuvers and flight regime it encounters. AE641: Aircraft Structures 1 1–4  Overview Major Categories of Aircraft Airplane. power-driven heavier-than-air aircraft, deriving its lift in flight chiefly from aerodynamic reactions on surfaces which remain fixed under given conditions of flight.(PCAR 2008) Rotorcraft. A power-driven heavier-than-air aircraft supported in flight by the reactions of the air on one or more rotors. (PCAR 2008) Glider. A non-power-driven heavier-than-air aircraft, deriving, its lift in flight chiefly from aerodynamic reactions on surfaces which remain fixed under given conditions of flight. (PCAR 2008) Lighter than air Aircraft. This includes hot air balloons, free balloons, weather balloons, airships or blimps. AE641: Aircraft Structures 1 1–5  Overview AE641: Aircraft Structures 1 1–6  Major & Minor Structural members Fixed wing Aircraft The wings on this type of flying machine are attached to the fuselage and are not intended to move independently in a fashion that results in the creation of lift. AE641: Aircraft Structures 1 1–7  Major & Minor Structural members Primary/Major Structural members he primary structure of a flight vehicle consists of the components that are necessary to sustain design ultimate flight and ground loads. Failure of the primary structure causes catastrophic collapse and loss of control. For aircraft the primary structure consists of the wings, fuselage, tail, and landing gear. Forms of construction are space trusses/frames, monocoque and semimonocoque. Secondary/Minor Structural members Secondary structure is that structure which carries only air or inertial loads generated on or within the secondary structure. AE641: Aircraft Structures 1 1–8  Fuselage Structure Truss Type A truss is a rigid framework made up of members, such as beams, struts, and bars to resist deformation by applied loads. The truss-framed fuselage is generally covered with fabric. AE641: Aircraft Structures 1 1–9  Fuselage Structure Monocoque Type The monocoque (single shell) fuselage relies largely on the strength of the skin or covering to carry the primary loads. The design may be divided into two classes: 1. Monocoque 2. Semimonocoque AE641: Aircraft Structures 1 1 – 10  Fuselage Structure The fuselage group can further be divided into major and minor members, for metal aircraft construction the following members are commonly found on large commercial aircraft:  Formers or frames  Longerons  Stringers  Bulkheads  Skin AE641: Aircraft Structures 1 1 – 11  Fuselage Structure Longerons Primary bending loads are taken by the longerons, which usually extend across several points of support. The longerons are supplemented by other longitudinal members, called stringers. Stringers The stringers are smaller and lighter than longerons and serve as fill-ins. They have some rigidity, but are chiefly used for giving shape and for attachment of the skin. The strong, heavy longerons hold the bulkheads and formers, and these, in turn, hold the stringers. All of these joined together form a rigid fuselage framework. AE641: Aircraft Structures 1 1 – 12  Fuselage Structure Function of Stringers and Longerons There is often little difference between some rings, frames, and formers. One manufacturer may call a brace a former, whereas another may call the same type of brace a ring or frame. Manufacturers. instructions and specifications for a specific aircraft are the best guides. Stringers and longerons prevent tension and compression from bending the fuselage. Stringers are usually of a one-piece aluminum alloy construction, and are manufactured in a variety of shapes by casting, extrusion, or forming. AE641: Aircraft Structures 1 1 – 13  Fuselage Structure Stressed Skin The metal skin or covering is riveted to the longerons, bulkheads, and otherstructural members and carries part of the load. The fuselage skin thickness will vary with the load carried and the stresses sustained at a particular location AE641: Aircraft Structures 1 1 – 14  Wing Group The wing group can further be divided into major and minor members, for metal aircraft construction the following members are commonly found on large commercial aircraft:  Spars  Ribs  Stringers  Skin AE641: Aircraft Structures 1 1 – 15  Wing Group Wing Spar Construction  Truss Type  Wet Wing Design  Beam Extrusion  C Beam  I Beam  Z Section  T Beam AE641: Aircraft Structures 1 1 – 16  Wing Group Wing Rib Construction  Truss Type  Metal with lightening holes  Solid Rib  Composite  Wood  Metal AE641: Aircraft Structures 1 1 – 17  Wing Group Wing Internal Structure and Coverings An example of how the wing skin is attached to the ribs using stringers or strips AE641: Aircraft Structures 1 1 – 18  Wing Group Wing Internal Structure and Coverings The picture above shows honeycomb structure to provide stiffness to the parts AE641: Aircraft Structures 1 1 – 19  Wing Group Wing Internal Structure and Coverings Parts of the aircraft that uses sandwich structure to increase stiffness AE641: Aircraft Structures 1 1 – 20  Wing Group Wing Internal Structure and Coverings The picture above shows a sample structure for a wing of a conventional commercial aircraft AE641: Aircraft Structures 1 1 – 21  Empennage Group The empennage group can further be divided into major and minor members, for metal aircraft construction the following members are commonly found on large commercial aircraft:  Spars  Ribs  Stringers  Skin  Control Surfaces AE641: Aircraft Structures 1 1 – 22  Powerplant Group The powerplant group can further be divided into major and minor members, for metal aircraft construction the following members are commonly found on large commercial aircraft:  Cowling  Nacelle  Pylons  Struts AE641: Aircraft Structures 1 1 – 23  Landing Gear Group The landing gear group can further be divided into major and minor members, for metal aircraft construction the following members are commonly found on large commercial aircraft:  Struts  Wheel well and doors  Wheel Hub AE641: Aircraft Structures 1 1 – 24  Types of Landing Gear From Left to right: Fixed (upper left), Retractable (lower left), Skid (helicopter), Float (amphibious), Ski (snow), and basket base AE641: Aircraft Structures 1 1 – 25  Summary AE641: Aircraft Structures 1 1 – 26