Question

Long-term deformation of a material under sustained constant loading is primarily governed by:

• A. Creep
• B. Modulus of toughness
• C. Modulus of resilience
• D. Yield strength

Hint:

Associate keywords: "long-term," "time-dependent," "constant load" \(\rightarrow\) Creep. "Energy to fracture" \(\rightarrow\) Toughness. "Elastic energy" \(\rightarrow\) Resilience. "Start of plastic deformation" \(\rightarrow\) Yield strength.

Answer 1

The Correct Option is A

Step 1: Analyzing the terminology.
- Creep: Refers to the slow, time-dependent, permanent deformation of a material when subjected to a constant load (stress) over a long duration. - Toughness: Total energy absorbed before fracture (area under the stress-strain curve). - Resilience: Capacity of a material to absorb energy elastically and release it upon unloading. - Yield strength: The stress point where plastic (permanent) deformation begins instantly.
Step 2: Matching with Question Requirements.
The question specifies "long-term deformation" and "sustained constant loading," which are the fundamental characteristics of creep.