Stress, strain, load definitions

Question 1

What is load

Answer 1

The force applied to a structure

Question 2

What are the 4 main loads?

Answer 2

Aerodynamic- aerofoil induced

Inertia- aircraft manoeuvres

Concentrated- landing taxiing braking

Engine- thrust, torque, gyroscopic forces

Question 3

What is Stress?

Answer 3

The internal force of a material which resists deformation by a load

Question 4

What are the 5 major stresses?

Answer 4

Tension- Skin during pressurisation
Torsion- Twisting
Bending- Stress beam
Compression
Shear- Skin rivets

Question 5

What is strain?

Answer 5

The deformation of a material caused by a load or stress

Question 6

What is fatigue?

Answer 6

Progressive and localised damage that occurs when a material is subject to cyclic loading

Question 7

What is bearing strength?

Answer 7

The load that a joint can hold (strength of the skin material)

The amount of force that will cause the rivet to tear out from the material

Sheet metal being able to withstand being torn away from the rivets in a joint.

Question 8

Shear strength vs bearing strength

Answer 8

Shear strength is a cutting force created by two forces acting in a opposite direction (Example: the amount of force needed to cut a rivet in two)

bearing strength is the load that a joint can hold (the strength of the skin material/the amount of force required to rip the rivet out of the metal)

Question 9

What is structural failure

Answer 9

The point at which a material fails

Question 10

Engine numbering system

Answer 10

Comencing from number one left hand outboard from the pilots view.