Mechanical Properties: Creep versus Fatigue

Define Creep.

• Creep is slow, permanent deformation of a material under constant stress over time, typically at high temperatures.

• Creep is the sudden breaking of a material under stress.

• Creep is the process of a material expanding when cooled.

• Creep is the ability of a material to conduct electricity.

Define Fatigue.

• Fatigue is progressive weakening and failure of a material due to cyclic loading over time.

• Fatigue is the immediate failure of a material under a single load.

• Fatigue is the process of material expansion due to heat.

• Fatigue is the strengthening of a material over time due to constant use.

Explain which part of a building would you like to be made of material that cannot be fatigued.

• Foundation

• Roof

• Walls

• Windows

Why must you, an engineer, design for torsional strength?

• To ensure structural integrity under twisting forces

• To reduce material costs

• To improve aesthetic appeal

• To increase weight

What is the real-life application of creep in jet engines?

• Improving fuel efficiency

• Enhancing engine durability

• Reducing noise pollution

• Increasing thrust power

Why must fatigue be prevented in a material?

• To maintain structural integrity and prevent failure

• To reduce weight

• To improve aesthetics

• To increase electrical conductivity

Why must fatigue be prevented in a material?

• To maintain structural integrity

• To reduce weight

• To improve aesthetics

• To increase cost

What is the definition of Shear Strength?

• The ability of a material to resist forces that cause its internal layers to slide past each other. It is the maximum stress a material can withstand before it fails due to shearing.

• The ability of a material to conduct electricity efficiently.

• The capacity of a material to absorb moisture from the environment.

• The property of a material to expand when heated.

What is the definition of Torsional Strength?

• The resistance of a material to twisting forces.

• The ability of a material to conduct electricity.

• The capacity of a material to absorb moisture.

• The measure of a material's thermal expansion.

Designing for torsional strength is essential because:

• it ensures structural integrity under twisting forces.

• it reduces the cost of materials.

• it improves the aesthetic appeal of the design.

• it simplifies the manufacturing process.