What is the allowable safe twisting moment for a composite shaft equivalent to_________________?
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Answer: B. minimum calculated value
Explanation
In composite shafts, the allowable safe twisting moment is governed by the weakest component, which corresponds to the minimum calculated value among the sections. Exceeding this lowest safe torque limit would cause the weakest material layer to fail prematurely, jeopardizing the entire assembly. Compatibility of twist requires that individual torque contributions be limited by the maximum allowable shear stress of each constituent. Composite shafts consist of two or more concentric or parallel materials bonded together to optimize torsional strength and weight. Torsional rigidity equations combine individual shear moduli and polar moments of inertia to determine overall shaft performance. Safe working stresses for each constituent material establish strict upper bounds on allowable applied twisting moments.
Selecting the maximum calculated value would overload the weaker material layer and cause immediate structural failure. Using a mean value is incorrect because stress distributions in composite shafts are non-uniform and bounded by material limits. Extreme values do not provide a safe design threshold for composite structures subject to distributed torsional stresses.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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