A material exhibits both time-dependent and temperature-dependent deformation under a constant load. Which of the following is the most appropriate description of this behavior?
- APlastic deformation
- BElastic deformation
- CCreepCorrect
- DFatigue
Solution
Concept
Creep is slow, time-dependent deformation under constant load, and it increases with temperature.
Step-by-step solution
1. Load is constant. 2. Deformation grows with time. 3. Deformation also depends on temperature. 4. This is the definition of creep. 5. Answer: (C).
Explanation
Creep is the slow increase of strain with time under constant stress. It is stronger at high temperature. Metals at high temperature and concrete under sustained load show creep.
Why the other options are wrong
(A) Plastic deformation is permanent but not mainly time-dependent. (B) Elastic deformation is instant and recoverable. (D) Fatigue is failure under repeated cyclic loading, not constant load.
Shortcut
Constant load + time + temperature = Creep.
Common mistake
Confusing creep (constant load) with fatigue (cyclic load).
Correct answer: C) Creep