Up to what point does Hooke’s law remain valid for elastic materials____________________?
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Answer: B. limit of proportionality
Explanation
Hooke law remains strictly valid for elastic materials up to the limit of proportionality. Beyond this specific stress point, the linear relationship between stress and strain ceases. Engineering calculations rely on this proportionality limit for elastic design formulas. Robert Hooke discovered that stress is directly proportional to strain in elastic deformations. The limit of proportionality marks the end of the straight line portion of stress-strain curves. Elastic limits and proportionality limits are close together but represent distinct metallurgical points.
Designers ensure structural components operate well below the proportionality limit to prevent permanent stretch. Material testing laboratories determine this limit to establish safe working stress levels for metals. Linear elastic analysis forms the basis of standard civil engineering structural design. The yield point occurs after proportionality and marks the onset of plastic permanent deformation. The breaking point represents the ultimate fracture failure stage of structural materials. The elastic limit is slightly higher than the proportionality limit in many ductile metals.
- Subject
- Engineering
- Category
- Mechanical Engineering
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- —
- Difficulty
- medium
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