For the principle of superposition to be valid, materials should behave in which manner?
Try it first: pick an option, then read the explanation.
Correct answer: A. linear-elastic
Asked in SSC JE 25/01/2018 (Morning)
Detailed Explanation
The principle of superposition says the effect of several loads acting together equals the sum of the effects of each load acting alone.
Why “linear-elastic” Is Correct
This works only if response is proportional to load (linear) and fully recoverable, independent of loading history (elastic). With non-linear or inelastic behaviour, the response to combined loads is not the sum of separate responses.
Why the Other Options Are Wrong
- B. non-linear elastic: Non-linear response means effects do not simply add.
- C. non-linear inelastic: Non-linear inelastic behaviour violates both conditions.
- D. linear inelastic: Inelastic (permanent) deformation depends on loading history.
Key Point
Superposition requires linear-elastic material and small deformations.
Key Concepts for Students
- Influence lines rely on superposition.
- Plastic analysis cannot use simple superposition.
- Large deflections (geometric non-linearity) also break superposition.
Practice more: this is question 31 in Stress and Strain MCQs – Part 3. Try the whole set and check every answer instantly.