Transcript
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BYRAVI
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PARTS OF AN AIRCRAFT
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Customer RequirementsPayload, Range, Endurance, Speed,
Research, Development and Marketanalysis
Requirements Satisfied ?
Final Evaluation
Flight Test
Detailed Design
ConceptualDesign
Preliminary Design
Test Article Fabrication
DESIGN PROCESS
No
Yes
Stop
Go
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CONCEPTUAL DESIGN
Preliminary Estimate of Take-off Weight Wing Loading Selection Main Wing Design Fuselage Design Horizontal and Vertical Tail Design
Engine Selection Take-off and Landing Enhanced Lift Design Structure Design and Material Selection Refined Weight Analysis
Static Stability and Control Cost Estimate Design Summary and Trade Study
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More weight
More lift needed
More wing area
More profile drag
More induced drag
More thrust
More fuel for a givenrange/mission
Larger fuel tank volume
Larger fuselage and/or wings
Larger engines
Heavier supporting structure
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FUEL FRACTION ESTIMATES
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FUEL FRACTION ESTIMATES
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3 VIEW
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PRELIMINARY DESIGN
Freeze The Configuration
Develop Lofting
Develop Test and Analytical Base
Design Major Items
Develop Actual Cost Estimate
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INBOARDS
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VISION REQUIREMENT
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DETAILED DESIGN
Design The Actual Pieces To Be Built
Design The Tooling and Fabrication Process
Test Major Item Structure, Landing Gear
Finalize Weight and Performance Estimates
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A/C STRUCTURES & SYSTEMS
AIRCRAFT CONSISTS OF:
1. STRUCTURES
* FUSELAGE
* WING
* EMPENNAGE
* LANDING GEAR
2. SYSTEMS
* POWER PLANT & FUEL SYSTEM
* FLIGHT CONTROL SYSTEM
* HYDRAULICS
* ECS
* ELECTRICAL & AVIONICS
PRIMARY FACTORS TO CONSIDER FOR AIRCRAFT STRUCTURES ARE:
STRENGTH
WEIGHT
RELIABILITY
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STRUCTURES
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FACTORS OF LOADS:
AIR LOADS :Pressure, lift, drag duringmaneour, gust load.
LANDING LOADS :On ground, water & arrestedlanding ( on ships).
POWER PLANT LOADS :Thrust, Torque.
Loads acting on each element of the structure are to be considered for design .
SPECIAL LOADS:
seat jettisoning, bird strike, cabinpressurization etc.
WT. & INERTIA LOADS :
component weight & inertia
LOADS ON AN AIRCRAFT
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MAIN STRUCTURE OR BODY OF THE AIRCRAFT
PROVIDES SPACE FOR1. PERSONNEL2. CARGO3. CONTROLS & ACCESSORIES
PROVIDES ATTACHMENT FOR1. NOSE CONE2. WIND SCREEN & CANOPY3. WING4. EMPENNAGE
5. NOSE & MAIN LANDING GEAR6. AIR INTAKE7. POWER PLANT
FUSELAGE
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3 MAJOR ASSEMBLIES:
FRONT FUSELAGE CENTRE FUSELAGE REAR FUSELAGE
FRONT FUSELAGE:
CONSISTS OF: NOSE CONE - Radar Antenna RADAR EQUIPMENT BAY Multi Mode Radar WIND SCREEN & CANOPY NOSE U/C BAY & ATTACHMENT
EQUIPMENT BAY AIR INTAKE STUB WING extension of Fuselage in Wing Shape DOORS COVERS
FUSELAGE MAJOR ASSEMBLIES
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INTERFACE
INTERFACES:
FRONT FUS. TO CENTER FUS.
CENTER FUS. TO REAR FUS.
WING TO FUSELAGE
FIN TO FUSELAGE
H.STABILIZER TO FUSELAGE
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STRUCTURAL ELEMENTS OF FUSELAGE
FRAMES / BULK HEADS
SKINS LONGERONS /STRINGERS
FLOORS
WALLS
AIR DUCT
DOORS & COVERS
Frame:
Maintains shape of fuselage
Reduces column length of the stringer
to prevent in-stability of the structureand for panel breaking.
* Light in construction
Bulkhead:
Heavier Transverse members locatedat intervals
Transfers concentrated loads to theshell of the A/C.
* Machined / Sheet metal built-up
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FRAME TYPES:
PRIMARY FRAMES : TransferConcentrated / Inclined Load(Machined Or Built-up )Eg: WING FUS, FIN FUS , U/C SEAT.
SECONDARY FRAMES: Totransfer air loads
(sheet metals)
STRUCTURAL ELEMENTS OF FUSELAGE
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BULKHEAD TYPES:
Open ring type
Close ring type
Full web type
STRUCTURAL ELEMENTS OF FUSELAGE
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STRUCTURAL ELEMENTS OF FUSELAGE
Skin:
Fabric Skin:
* Truss Type
* Slow speed A/C
* Takes only Air Loads & cannot resist shear / bending load.
Stressed skins:* Sheet metal/composites
* Riveted or bonded to the Frames & Stringers.
* Takes Air Loads, Shear, Bending Loads and Torsional Loads
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TOP
SHEET
BOTTOMSHEET
CORE
Engine
Cowling
STRUCTURAL ELEMENTS OF FUSELAGEComposites:
Composite Al.
Density(gm/cc) 1.8 2.4
Strength(Mpa) 1200 400
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Stringer / Longeron:
* A longitudinal stiffener attached toskin
* Increases effectiveness of skin
* Increases Compressive and shearcritical stress.
TYPICAL SKIN & STRINGERASSEMBLY
STRUCTURAL ELEMENTS OF FUSELAGE
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STRUCTURAL ELEMENTS OF FUSELAGE
WALLS & FLOORS:
Transfer the shear load Side walls for fuel tanks
Side walls for landing gear bay.
Tank floors and ceilings
Equipment bay floors
Cockpit floors
TYPICAL FLOOR ASSEMBLY
TYPICAL WALL ASSEMBLY
FLOOR
STRINGERSWALL
LONGERON
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Most important lift-producing part of the aircraft.
Wings vary in design depending upon the aircraft type and its purpose.
The shape of a wing greatly influences the performance of an airplane, Speed ofan airplane, its maneuverability & its handling qualities
Wings also carry the fuel for the airplane.
Types:1. Straight2. Sweep (forward and back)3. Delta
4. Swing-wing.
W I N G
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Straight Wing:* for small, low-speed airplanes
* General Aviation airplanes often of this type* Provides good lift at low speeds & Stable flight* Not suitable for high speeds.
W I N G
Delta Wing:
* Looks like a large triangle from top.
* Can reach high speeds (supersonic aairplanes LCA, Concorde)
* Landing speeds are very fast.
SimpleDelta
ComplexDelta
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Sweep-back Wing:* for most high-speed airplanes.* Creates less drag* More unstable at low speeds.* Take off and Landing at a high rate of speed.
Forward-sweep wing:* Yet to make it into mass production.* Highly maneuverable & highly unstable (X-29).
* Computer-based control system is a must to helpthe pilot fly.
Swing Wing:* Has high lift characteristics of a primarily straight
wing with the ability of the sweepback wing to
enable high speeds. During landing and takeoff, the wing swings into analmost straight position.
During cruise, the wing swings into a sweepbackposition.
W I N G
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ELEMENTS OF WING
Spar: It is a primary beam, which extends tothe full length of the wing.
Rib: a light structure conforming to the shapeof the airfoil over which the skin is attached
and transfers the air load to the spars.Nose rib: Rib between front spar and theleading edge of the airfoil.
Inter-Spar rib: Rib between the adjacentspars.
Nose Rib
Inter sparRib
LighteningHoles
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Spoilers: Located on top of the wings. Opposite effect of flaps and slats.
Reduces lift and increases the drag. Helps the airplane to slow down sooner.
Slats: Located on the leading edge of the wings.
Flaps: Located on the trailing edge of the wings.
Aileron: Hinged on the trailing edge of the wing. Helps in rolling motion of theairplane.
ELEMENTS OF WING
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EMPENNAGE
Commonly called as Tail of A/c.
Consists of Vertical stabilizer(Fin) and horizontal stabilizer(Tail Plane). Stabilizers help the aircraft maintain a straight path through the air as it flies.
Stabilizers act like the feathers on an arrow.
EFFECTS OF CONTROL SURFACES
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EFFECTS OF CONTROL SURFACES
Elevator
AileronRudder
Rudder
Elevator
Aileron
Flap
Slats Spoilers
LANDING GEAR
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LANDING GEAR
MAIN LANDING GEARNOSE LANDING GEAR
Actuated by
Hydraulic System
Absorbs the forcesimposed on the A/c by
take-offs & landings.
NLG can be steeredfrom the cockpit.
MLG is equipped withbrakes for stopping theA/c & steering the A/con the ground.
AIRCRAFT STRUCTURE JOINTS
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AIRCRAFT STRUCTURE - JOINTS
JOINTS:
Structural Elements are joined together to form sub-assembly
Sub-assemblies are joined together to form major assemblies (Fuselage,Wing, Empennage, Canopy & Wind Shield etc.)
TYPES OF JOINTS:
Temporary / Removable joints : Bolted (shear / tension).
Permanent Joints : Riveted and Welded joints.
IMPORTANT JOINTS : Engine mount
Landing gear attachment
Fin attachment
Canopy & wind shield
Wing attachment
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AIRCRAFT STRUCTURE - JOINTS
Landing Gear attachment
AIRCRAFT STRUCTURE JOINTS
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FASTENERS:
AIRCRAFT STRUCTURE - JOINTS
1. Permanent Fasteners(Standard):
Rivets : HS 1005, HS 1006, HS 1014, HUCK MLGPL
Blind Rivets: NAS 1919B, NAS 1921B
(Used where there is no access on the other side)
2. Removable Fasteners (Standard):
Bolts : HS 1001, HS 1002Nuts : 3373A
Anchor Nuts: 3381A, 155H940, 155H942
3. Special Fasteners:
Wing Fuselage Attachment Bolts
MATERIALS
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Aircraft Materials should have:
* Good strength
* Good Stiffness* Less Weight
* High Reliability
Material consideration for selection: Strength to weight ratio (Ultimate tensile strength to Density
) higher the ratio is better.
Stiffness to Weight ratio ( Young's modulus to Density )
Availability
Ease of manufacturing
Cost Effective
MATERIALS
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THANK YOU
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