In bolted assemblies, the critical shear plane should ideally be located_________________?
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Answer: D. never be across the threaded portion
Explanation
In bolted joints, shear planes must be located across the unthreaded shank portion rather than the weaker threaded section. The effective cross-sectional area of the unthreaded shank is significantly larger than the minor thread root diameter. Placing shear loads across threads creates high stress concentrations that drastically reduce the load-bearing capacity of the fastener. Bolts are threaded fasteners designed primarily to clamp components together through pre-tensioning rather than acting as shear pins. When shear loading is unavoidable, mechanical designers use fitted bolts with smooth unthreaded shanks matching the hole diameter precisely. Threaded sections have reduced cross-sectional areas and serve as stress risers when subjected to transverse shear forces.
Option A is incorrect because locating shear planes across threads introduces dangerous stress concentrations and reduces joint strength. Option B is wrong because shear planes must be perpendicular to the bolt axis to properly resist transverse loads. Option C is incorrect because shear planes are always normal to the longitudinal axis of the fastener shank regardless of threads.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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