Strain Energy in Volumetric Compression For a body subjected to uniform hydrostatic pressure p producing volumetric strain, how does the strain energy due to volumetric strain vary with volume, pressure, and bulk modulus?
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ADirectly proportional to volume
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BDirectly proportional to pressure squared
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CInversely proportional to bulk modulus
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DAll of the above
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ENone of these
Answer
Correct Answer: All of the above
Explanation
Introduction / Context:Strain energy is the elastic energy stored in a body due to deformation. Under uniform hydrostatic pressure, the energy associated with volumetric strain depends on pressure, bulk modulus, and the volume of the body.
Given Data / Assumptions:
- Hydrostatic pressure p.
- Bulk modulus K of the material.
- Body volume V.
Concept / Approach:For volumetric compression, the classic result is U_v = (p^2 * V) / (2 * K), assuming linear elasticity and small strains. This expression reveals the proportionalities directly.
Step-by-Step Solution:Start from U = 1/2 * stress * strain * volume for linear elastic response.For hydrostatic loading: volumetric strain = p / K.Thus U_v = 1/2 * p * (p / K) * V = (p^2 * V) / (2 * K).
Verification / Alternative check:Dimensional analysis confirms energy dimensions are consistent when combining p^2, V, and K in this form.
Why Other Options Are Wrong:
- Each individual statement a–c is true; the most complete option is “All of the above”.
Common Pitfalls:Mixing up bulk modulus in numerator rather than denominator or forgetting the square on pressure leads to incorrect trends.
Final Answer:All of the above