Creep is the permanent deformation that increases with time under constant load.

Creep is the permanent deformation that increases with time under constant load.

• A. Elastic deformation
• B. Plastic deformation during loading
• C. Permanent deformation that increases with time under constant load
• D. Creep resistance decreases with temperature

Answer: (C)

Creep is the time-dependent permanent deformation that occurs when a material is under a constant load, especially at elevated temperature. The key idea is that the deformation keeps accumulating with time even though the load doesn’t change, and it remains after the load is removed. This sets it apart from elastic deformation, which is reversible, and from plastic deformation during loading, which happens once the stress exceeds yield and isn’t driven by long-term time under a constant load. In real materials, creep unfolds in stages—primary, secondary, and tertiary—where the rate changes over time and higher temperatures tend to accelerate the creep process. The statement about creep resistance and temperature describes how creep behavior evolves with temperature, not the definition of creep itself.

Creep is the time-dependent permanent deformation that occurs when a material is under a constant load, especially at elevated temperature. The key idea is that the deformation keeps accumulating with time even though the load doesn’t change, and it remains after the load is removed. This sets it apart from elastic deformation, which is reversible, and from plastic deformation during loading, which happens once the stress exceeds yield and isn’t driven by long-term time under a constant load. In real materials, creep unfolds in stages—primary, secondary, and tertiary—where the rate changes over time and higher temperatures tend to accelerate the creep process. The statement about creep resistance and temperature describes how creep behavior evolves with temperature, not the definition of creep itself.