WING SPAR

Md Jameel uddin

14101038

• In a fixed-wing aircraft, the spar is often the main structural member of the wing, running span wise at right angles (or thereabouts depending on wing sweep) to the fuselage.

Function of Wing spar: Spar is a heavy beam running span wise to take

transverse shear loads and span wise bending. It is usually composed of a thin shear panel (web) with a

cap or flange at the top and bottom to take bending. Ribs are also supported by span wise spars.

The air loads act directly on the wing cover (skin) which transfers it to rib which further transfers load in shear to spar webs and distribute load between them in proportion to web stiffeners.

Some of the forces acting on wing spar are:• Upward bending loads resulting from the wing lift force that

supports the fuselage in flight. These forces are often offset by carrying fuel in the wings or employing wing-tip-mounted fuel tanks.

• Downward bending loads while stationary on the ground due to the weight of the structure, fuel carried in the wings, and wing-mounted engines if used.

• Drag loads dependent on airspeed and inertia.• Rolling inertia loads.• Chordwise twisting loads due to aerodynamic effects at high

airspeeds often associated with washout, and the use of ailerons resulting in control reversal.

Substitute material:

• Aerospace structures are still the key application for high modulus carbon fibre composites, used as a substitute for aluminium in particular.

• A carbon epoxy composite(AS4/3501-6) is used as substitute material.

• 3501-6 is an amine cured epoxy resin system supplied with unidirectional or woven carbon or glass fibers. Typical reinforcement is continuous AS4 carbon filaments.

• Its density is 1.56gm/cm3.

Material used:• Aluminium alloy 7075 is an aluminium alloy,

with zinc as the primary alloying element.  It is strong, with strength comparable to many steels, and has good fatigue strength and average machinability, but has less resistance to corrosion than many other Al alloys.

• 7075 aluminum alloy's composition roughly includes 5.6–6.1% zinc, 2.1–2.5% magnesium, 1.2–1.6% copper, and less than half a percent of silicon, iron, manganese, titanium, chromium, and other metals.

• It is produced in many tempers, some of which are 7075-0, 7075-T6, 7075-T651. Aluminium 7075A has a density of 2.810 g/cm³(0.1015 lb./in³).

• 40% lighter than aluminum.• High strength to weight ratio, stiffness• High corrosion resistance, improved fatigue life.• Application flexibility.