Question One: Structure Of The Wing
The principal components of the wing are; spars stringers and ribs. The spars are the main structures of the wing and run span-wise at right angles to the fuselage. They function to carry flight loads and weight of the entire wings when aircraft is still on the ground. The wing spars are manufactured out of metal, wood or composite materials depending on the design of a specific aircraft.
The stringers are longitudinal elements of power set that run fore and aft in the wing. They are responsible for preventing the skin of the wing from buckling when exposed to loads and further prevent the spread of cracks that may lead to bending.
The ribs give shape to the wing of the aircraft by combining with the stringers and the spars. They support the skin and purpose to prevent the fuel surging during the maneuver of the aircraft. The ribs are essential attachments to other components of the wing such as the flaps and under carriages. In aircrafts with the fuel tanks in the wings, the ribs are responsible for separating the individual fuel tanks in the wings. The ribs define the thickness of the wings(airfoil). Wing ribs are manufactured from either metal or wood. The rib is composed if the rib cap which is responsible for stiffening and strengthening the rib thus providing attachment surface for the wing covering.
The wings also composed of the ailerons and flaps which are attached to its rear or trailing edges. The ailerons rectangular shaped airfoils that extend from the midpoint of each wing externally towards the tip moving in the opposite directions to create aerodynamic forces that are responsible for rolling of the plane. The flaps on the other hand extend near the midpoint of the wings and outward from the fuselage. Extending the flaps simultaneously outwards increases the lifting force of the wings to facilitate takeoffs and landings.
The structural components of the fuselage vary depending on whether it takes the truss, monocoque or semi-monocoque design. the classification is based on the arrangement of their components in regards to force resistance. The design of the fuselage ensures that it stands various forces that it may experience. The fuselage plays a great role in stabilization and position control. Its structure is specific to withstand various kinds of stresses.
The fuselage has longerons which extend across many frame members thus helping the skin support primary loads.
Stringers are structural composition of the fuselage. Longitudinal members are components of the fuselage which are always lighter and more numerous compared to the longerons. They are of different shapes and made from different materials that have high strength abilities. They are combined to form the stringers. The stringers together with the longerons prevent tension and compression from bending the fuselage.
The frame is another structural component of the fuselage. It is generally the skin of the aircraft and made form various materials that mainly exhibit high resistance to heat and corrosion, are light and strong. The frame holds the external and internal components thus its strength and light weight is essential to allow it prevent the fuselage from tension and compression that may lead to bending.
The fuselage is cylindrically shaped to address the stresses arising from the external and internal loads. The shape helps in reducing pressure arising by distributing the load evenly so as to avoid break or cracking which arise from tension and compression. The bulkheads at the cabin are dome shaped for better pressure distribution and streamlining to reduce the stress of tension and shear.
In semi-monocoque fuselages the frame is designed in manner that it is thicker at points where the load is heavier and lighter where less load is handles. This ensures that the stresses are evenly distributed to avoid tension and torsion in the parts where fixings and fittings on the frame are done. On the other hand, monocoque designs deal with compression and tension that may lead to cracking or bending by having frames made out of strong composite materials such as glass fiber through glass foam sandwich construction.
Both metallic and non-metallic materials are used in aircraft construction. Metallic materials are more popular in aircraft construction owing to various attributes. there is great evolution on what materials are used due to the need to have light, heat resistant, crack resistant, strength and fatigue resistant.
Aluminum is one material used because of its low density of 2.7 g/cm3, high corrosion resistance, technological effectiveness and good thermal and electric conductivity. It finds application in the fuel tanks because of its features especially the 5052-H32 alloy.
Steel an alloy of iron and carbon is approximately three times stronger and heavier than aluminum. It is highly resistant to heat and strong making it applicable in the landing sections and skin surface of the aircrafts.
Composite materials are used in aircraft construction. This involves the use of fiber in the right direction and quantity. Fibers are essential anti-buckling agents when they are embedded on resins. They are string and light a feature highly considered in aircraft construction. They are applied in the honeycombs where light weight and strength is needed. The composite materials such as fiber glass and carbon fiber increase fuel efficiency and thus are used in the hydraulic systems and the fuel tanks. Plastics are also used in the construction. Thermosetting plastics are combined with fiber glass to have decorated windows. The transparent plastics are used on the windows because of their ability to hardened when heated to specific temperatures. Plastics have high durability, high corrosion resistance and flexibility making them appropriate.
Wood has for a long time been a material in construction though its use is declining. It strength varies from which part of the tree it is obtained from and the type of tree itself thus providing variety. Wood can be used in the main spars because of the weight-strength ratio and the ability to be straight grained free of defects. It is also used in the webs and flanges of the web ribs. The Norwegian spruce which is recognized for its stiffness is used in the fuselage struts so as to resist bending. Ash which another wood is used in the carriage struts because of its ability to be easily curved while maintaining its strength.
Titanium is another material used in construction of aircrafts because of its strength, high temperature resistance and high corrosion resistance. It is majorly used in the swivel wings and the hydraulic systems.
Nickel alloys find their use in aircraft construction. They are easily welded or machined. They are highly resistant to corrosion heat and are strong. They are thus used in gears and exhaust systems of the aircraft.