Stress Flashcards
What is stress in the context of machines?
Stress is the internal reaction that occurs in an object when an external force is applied.
How is stress typically measured?
Stress is measured in pounds per square foot or pounds per square inch (psi).
What are the five forms of stress?
- Tension
- Compression
- Torsion
- Bending
- Shear
Define tension.
Tension is a force that tries to pull an object apart.
What happens to the ropes in a block and tackle system when a weight is lifted?
The ropes and blocks are under tension, trying to pull apart.
Define compression.
Compression is a force that tries to crush an object.
How does a rivet work in the context of compression?
A rivet is crushed to expand and fill a hole, securely holding pieces together.
What is torsion?
Torsion is the stress experienced when an object is twisted.
What two stresses make up torsion?
- Tension
- Compression
What is an example of torsion in a turbofan engine?
The turbine shaft experiences torsion stress as torque is applied.
What happens to an airplane wing during flight?
The wing experiences bending due to aerodynamic lift.
What stresses occur on the wing of an airplane while it is on the ground?
- Compression on the bottom of the wing
- Tension on the top of the wing
Define shear.
Shear is a stress that tries to cut or slice through an object.
What is a clevis bolt used for in aviation?
A clevis bolt secures a cable to a part of the airframe and experiences shear stress.
What is strain?
Strain is the change in shape or distortion of an object due to applied stress.
