Consider the following statements regarding simple stresses and strains : 1. Limit of proportionality is the limiting value of the stress up to which stress is proportional to strain. 2. Upper yield point is the stage at which the stress remains same but strain increases for some time. 3. The stress at which the specimen finally fails is called breaking point. Which of the above statements are correct?
To determine the correctness of the given statements regarding simple stresses and strains, let's analyze each statement:
- Limit of Proportionality: This is defined as the maximum stress up to which the stress is directly proportional to the strain. Beyond this limit, Hooke's Law (stress is proportional to strain) no longer holds true. Statement 1 is correct.
- Upper Yield Point: This refers to a point in the stress-strain curve of certain materials (especially mild steel) where the stress remains constant while strain increases significantly. Thus, the statement "the stress remains the same but the strain increases for some time" at the upper yield point is true. However, this point does not define the breaking or failure of the specimen but rather the yielding. This statement is partially correct in definition but doesn't directly correlate to breaking points.
- Breaking Point: The breaking point is the stress at which a specimen ultimately fracturess or fails. This is indeed where the material can no longer sustain any stress, leading to failure. Statement 3 is correct.
Based on the analysis:
- Statement 1 is correct as it correctly defines the limit of proportionality.
- Statement 2 is not correct in terms of the context of the breaking point but defines a yield behavior.
- Statement 3 correctly defines the breaking point.
Therefore, the correct statements are 1 and 3. The correct answer is 1 and 3 only.
Important Questions from Stress-Strain Diagram
The property of a material which absorb large amount of energy prior to fracture is _______.
In the engineering stress-strain curve for mild steel, the Ultimate Tensile Strength (UTS) refers to
True stress experienced by a material is_______ than the engineering stress at a given load.
Strain hardening
________ is represented graphically by the area under the stress-strain curve up to the proportional limit.
