WING MATERIALS, APPLICATIONS AND CONSTRUCTION

CONFIGURATIONS

CREW:

• Melesio Ruiz Olguín.

• Aldaid Ángeles Ángeles.

• Brandon Alexis Cano Díaz.

• Rodrigo Valdez Rodríguez.

• Sergio Cortés Valle.

• 1.-History

• 2.- Monocoque and semi-monocoque structures

• 3.- Monospar and Multispar

• 4.- Aircraft Wings Materials

• 5.- Drive systems

•

1.HISTORY

WOOD, LINEN AND WIRE BRACING (1915-1925)

• Abeto

• E=9000Mpa

• Resistencia a la tracción: 70Mpa

• Densidad: 400kg/m3

• Abedul

• E=14250Mpa

• Resistencia a la tracción 100Mpa

• Densidad: 630kg/m3

LINEN

• Linen is a bast fiber. Flax fibers vary in length from about 25 to 150 mm (1 to 6 in) and average 12-16 micrometers in diameter.

• There are two varieties: shorter tow fibers used for coarser fabrics and longer line fibers used for finer fabrics.

• Flax fibers can usually be identified by their “nodes” which add to the flexibility and texture of the fabric.

WIRE BRACING

• In general, bracing allows a stronger, lighter structure than one which is unbraced, but external bracing in particular adds drag which slows down the aircraft and raises considerably more design issues than internal bracing.

WOOD, LINEN AND ARC-WELD TUBE BRACING (1925-1933

• In mid-1925 Boeing replace wires welded to the wing structure, so giving greater rigidity to the semi wings.

• It was also implemented to strengthen the internal structure of the semi wings and connections with the fuselage

ALL-METAL CONSTRUCTION (1930-PRESENT)

• In the interwar period all technology related to aviation was developed, performing major advances in aircraft design, and still the moment that began to operate the first airlines. The planes began to replace wood by metal widely

STEEL AND STEEL ALLOYS

• The steel has good qualities about resistance, but its density is excessive and has serious corrosion problems.

• However, replaced wood in construction: already in the First World War Junkers used sheets corrugated aluminum to save weight of the stiffeners and create the 1st all-metal plane

TITANIUM • Advantages

• Its density is between aluminum and steel

• It performs well against corrosion

• It withstands high temperatures (400 – 500 ºC)

• Disadvantages • Its properties are degraded in

saline environments

• Its cost is 7 times that of aluminum

ALUMINUM • In the nineteenth century,

aluminum was so expensive to produce that was considered a semi-precious metal.

• Besides the qualities of unalloyed aluminum or refine, they left much to be desired, to think about it for some industrial use (resistance aluminum alloy is 6 to 8 times higher than unalloyed aluminum).

COMPOSITES INTRODUCED (1960-PRESENT) • Fibrous composite materials

were originally used in small quantities in military aircraft in the 1960s, and within civil aviation from the 1970s. By the 1980s, composites were being used by civil aircraft manufacturers for a variety of secondary wing and tail components such as rudder and wing trailing edge panels.

2.-MONOCOQUE AND SEMI-MONOCOQUE STRUCTURES

Pic 1. Wing

1.1 MONOCOQUE STRUCTURES

• Set of “frames” covered by metallic skin, all applied loads are supported by skin while frames provide stiffness

1.2 SEMI-MONOCOQUE STRUCTURES

• Semi-Monocoque structure is an improvement of monocoque , it has intern frames, skin, stringers ,etc in order to provide more stiffness

1.3 WING CONFIGURATION

• Wing configuration is semi monocoque and contains:

• SPAR: Most aircrafts contain just 2, and they provide resistance against bending.

Pic 2 a) Spar

• Ribs: Provide resistance against torsion, and they have cut pieces for lighten up the weight, and they also shape the fuel tank

Pic 2 b) Ribs Pic 2.1 Ribs

• Stringers: Small beams located between ribs to avoid skin’s buckling , nowadays they’re made of composite materials.

Pic 2 c) Stringers Pic 2.2 Stringers

• Skin: Wing’s external part, they are subjected to shear stress and they’re useful as an isolator of the fuel and environment

Pic 2.3 Skin

• Struts: A strut is a structural component designed to resist longitudinal compression, it is used to keep two components separate, Struts are applied to a high-wing monoplane and act in tension during flight.

Pic 2.4 Grumman F3F Struts

3.MONOSPAR

• The monospar wing incorporates only one main spanwise or longitudinal member in its construction.

• Supply the necessary contour or shape to the airfoil. Although the strict monospar wing is not common, this type of design modified by the addition of false spars or light shear webs along the trailing edge for support of control surfaces is sometimes used.

MULTISPAR

• The multispar wing incorporates more than one main longitudinal member in its construction.

ADVANTAGES

• Ease of manufacturing.

• Simple design and ease of ribs.

• Increased stiffness of the outer wing panel.

• Rational technological spacing of manholes at the bottom panel due to the small number of ribs.

DISADVANTAGES

• Larger specific weight of regular zones of the panels.

• No analogues for long-range aircraft high level of technical risk.

4. AIRCRAFT WINGS MATERIALS

WING CONSTRUCTION

Wing construction is basically the same in all types of aircraft. Most modern aircraft have all metal wings, but many older aircraft had wood and fabric wings.

• To maintain its all-important aerodynamic shape, a wing must be designed and built to hold its shape even under extreme stress.

• Basically, the wing is a framework composed principally of spars, ribs, skin and stringers.

MATERIAL SELECCIÓN

Aircraft designers continue apply materials and structural concepts to provide benefits in performance, durability, compliance with environmental regulations, and most recently, acquisition and maintenance costs.

• Aluminum is the most common material from which to construct wings, but they can be wood covered with fabric, and occasionally a magnesium alloy has been used.

• Moreover, modern aircraft are tending toward lighter and stronger materials throughout the airframe and in wing construction. Wings made entirely of carbon fiber or other composite materials exist, as well as wings made of a combination of materials for maximum strength to weight performance

CONSIDERATIONS: ATTACH OF THE WINGS

Three systems are used to determine how wings are attached to the aircraft fuselage depending on the strength of a wing's internal structure.

• The strongest wing structure is the full cantilever which is attached directly to the fuselage and does not have any type of external, stress-bearing structures.

• The semicantilever usually has one, or perhaps two, supporting wires or struts attached to each wing and the fuselage.

• The externally braced wing is typical of the biplane (two wings placed one above the other) with its struts and flying and landing wires

WING CONFIGURATION

• The wings are built in many shapes and sizes.

• Wing design can vary to provide certain desirable flight characteristics.

• Control at various operating speeds, the amount of lift generated, balance, and stability all change as the shape of the wing is altered.

WING SPARS

• Spars are the principal structural members of the wing.

• Spars may be made of metal, wood, or composite materials depending on the design criteria of a specific aircraft.

They can be generally classified into four different types by their cross sectional configuration.

(A) Solid

(B) Box shaped

(C)Partly hollow

(D) I-beam

WING SPARS

• Currently, most manufactured aircraft have wing spars made of solid extruded aluminum or aluminum extrusions riveted together to form the spar

• In an I–beam spar, the top and bottom of the I–beam are called the caps and the vertical section is called the web.

WING RIBS

• The ribs give the wing its cambered shape and transmit the load from the skin and stringers to the spars.

• Wing ribs are usually manufactured from either wood or metal.

The three common types of wooden ribs are:

• plywood web

• lightened plywood web

• truss types

WING SKIN

• The skin on a wing is designed to carry part of the flight and ground loads in combination with the spars and ribs.

WING SKIN

• The wing skin on an aircraft may be made from a wide variety of materials such as fabric, wood, or aluminum. But a single thin sheet of material is not always employed.

• On aircraft with stressed-skin wing design, honeycomb structured wing panels are often used as skin.

“A honeycomb structure is built up from

a core material resembling a bee

hive’s honeycomb which is laminated

or sandwiched between thin outer skin

sheets”

NACELLES

• Nacelles (sometimes called “pods”) are streamlined enclosures used primarily to house the engine and its components

• The framework of a nacelle usually consists of structural members similar to those of the fuselage.

• Lengthwise members, such as longerons and stringers, combine with horizontal/vertical members, such as rings, formers, and bulkheads, to give the nacelle its shape and structural integrity.

• The exterior of a nacelle is covered with a skin or fitted with a cowling which can be opened to access the engine and components inside. Both are usually made of sheet aluminum or magnesium alloy with stainless steel or titanium alloys being used in high-temperature areas, such as around the exhaust exit.

5.-DRIVE SYSTEMS

• Are the components that let to the wing delivers a control during the aircaft flights.

CABLE DRIVE

• This drive system has been applied on the first aircrafts

• Advantages:

Used for its light weight

Simplicity

• Disadvantages:

cable pre-loading will be required to prevent the slack due to the applied loads, temperature changes and wing box deflection

UTILITY CABLE

• Aspects:

• Choose from stainless or galvanized carbon steel

wire rope

• Steel core, recommended

• Configuration:

• 7X7 or 7X18

• More commun:

• MIL-DTL-83420

FAILURE

• Failure of an Aileron Control Cable in an Aircraft:

• Summary: A cable controlling the aileron movement in an aircraft had broken.

• Conclusion : The snapping of the cable was due to excessive thinning of its strands due to contact wear.

HYDRAULIC DRIVE

• Advantages:

Simple to install, less components involved

Less weight is involved since only tubing, fluid, actuator and support instalation have to be dealt with

• Disadvantages:

Posibility of leaking in tubing and total hydraulic failure makes the flap inoperable

Increased posibility of fire hazard along the wing area

MECHANICAL DRIVE

• Advantages:

A very positive control of the flap

Operation of the system complataly independent

Do not créate the posibility of fire hazard in the wing área of the plane

• Disadvantages:

A considerable wight involved due to the electric motor

Numerous wearing parts like bearings, transmition shaftingd, gears.

Requires a lot of maintenance