MODULE - 4
AIRCRAFT STRUCTURES AND MATERIALS
• General types of construction and structural layout
• Monocoque, semi-monocoque, corrugated, sandwich structure, reinforced and
honeycomb structures, geodesic construction
• Aerospace materials, metallic and non-metallic materials, use of aluminium al
titanium, stainless steel, composite, and ceramic materials.
• Flight envelope and V‐n diagrams
,Major Structural Stresses :
• Aircraft structural members are designed to carry a load or to resist stress.
• Every part of the aircraft must be planned to carry the load to be imposed upon it.
determination of such loads is called stress analysis.
• Stress is defined as the force acting on the unit area of a material.
• External loads or forces cause stress. Stress is a material’s internal resistanc
counterforce, that opposes deformation.
• The degree of deformation of a material is strain.
• The strain is defined as the ratio of change in dimensions of the body to its orig
dimension.
,• When a material is subjected to a load or force,
that material is deformed, regardless of how
strong the material is or how light the load is.
• There are five major stresses to which all aircraft
are subjected
• Tension
• Compression
• Torsion
• Shear
• Bending
, Tension: Compression:
• Tension(Tensile stress) is the stress that resists • Compression is the stress that resis
a force that tends to pull something apart. crushing force.
• The engine pulls the aircraft forward, but air • Compression is the stress that tends to sh
resistance tries to hold it back. The result is
or squeeze aircraft parts.
tension, which stretches the aircraft.
𝑃𝑢𝑠ℎ (𝑅𝑒𝑠𝑖𝑠𝑡𝑖𝑛𝑔 𝑓𝑜
𝑇𝑒𝑛𝑠𝑖𝑙𝑒 𝐿𝑜𝑎𝑑 • Compressive stress =
• Tensile stress = 𝐴𝑟𝑒𝑎
𝐴𝑟𝑒𝑎
𝐼𝑛𝑐𝑟𝑒𝑎𝑠𝑒 𝑖𝑛 𝐿𝑒𝑛𝑔𝑡ℎ 𝐷𝑒𝑐𝑟𝑒𝑎𝑠𝑒 𝑖𝑛 𝑙𝑒𝑛𝑔𝑡ℎ
• Tensile strain = • Compressive strain =
𝑂𝑟𝑖𝑔𝑖𝑛𝑎𝑙 𝐿𝑒𝑛𝑔𝑡ℎ 𝑂𝑟𝑖𝑔𝑖𝑛𝑎𝑙 𝐿𝑒𝑛𝑔𝑡ℎ
AIRCRAFT STRUCTURES AND MATERIALS
• General types of construction and structural layout
• Monocoque, semi-monocoque, corrugated, sandwich structure, reinforced and
honeycomb structures, geodesic construction
• Aerospace materials, metallic and non-metallic materials, use of aluminium al
titanium, stainless steel, composite, and ceramic materials.
• Flight envelope and V‐n diagrams
,Major Structural Stresses :
• Aircraft structural members are designed to carry a load or to resist stress.
• Every part of the aircraft must be planned to carry the load to be imposed upon it.
determination of such loads is called stress analysis.
• Stress is defined as the force acting on the unit area of a material.
• External loads or forces cause stress. Stress is a material’s internal resistanc
counterforce, that opposes deformation.
• The degree of deformation of a material is strain.
• The strain is defined as the ratio of change in dimensions of the body to its orig
dimension.
,• When a material is subjected to a load or force,
that material is deformed, regardless of how
strong the material is or how light the load is.
• There are five major stresses to which all aircraft
are subjected
• Tension
• Compression
• Torsion
• Shear
• Bending
, Tension: Compression:
• Tension(Tensile stress) is the stress that resists • Compression is the stress that resis
a force that tends to pull something apart. crushing force.
• The engine pulls the aircraft forward, but air • Compression is the stress that tends to sh
resistance tries to hold it back. The result is
or squeeze aircraft parts.
tension, which stretches the aircraft.
𝑃𝑢𝑠ℎ (𝑅𝑒𝑠𝑖𝑠𝑡𝑖𝑛𝑔 𝑓𝑜
𝑇𝑒𝑛𝑠𝑖𝑙𝑒 𝐿𝑜𝑎𝑑 • Compressive stress =
• Tensile stress = 𝐴𝑟𝑒𝑎
𝐴𝑟𝑒𝑎
𝐼𝑛𝑐𝑟𝑒𝑎𝑠𝑒 𝑖𝑛 𝐿𝑒𝑛𝑔𝑡ℎ 𝐷𝑒𝑐𝑟𝑒𝑎𝑠𝑒 𝑖𝑛 𝑙𝑒𝑛𝑔𝑡ℎ
• Tensile strain = • Compressive strain =
𝑂𝑟𝑖𝑔𝑖𝑛𝑎𝑙 𝐿𝑒𝑛𝑔𝑡ℎ 𝑂𝑟𝑖𝑔𝑖𝑛𝑎𝑙 𝐿𝑒𝑛𝑔𝑡ℎ
