When a shaft is subjected to pure twisting, the type of stress developed in the shaft is
- ABending Stress
- BAxial Stress
- CShear StressCorrect
- DNormal Stress
Solution
Concept
Stress developed under pure shaft torsion
Formula
NONE
Step-by-step solution
1. Pure twisting or torsion applies a torque about the longitudinal axis of a member. 2. Torque produces angular deformation between adjacent cross-sections of the shaft. 3. According to torsion theory, this induces pure torsional shear stress across the cross-section. Answer: C
Explanation
Pure twisting occurs when a torque is applied to a member without any simultaneous bending moment or axial load. This torsional force generates internal shearing forces that act across the cross-sectional planes of the shaft. As a result, pure shear stress is developed throughout the shaft material.
Why the other options are wrong
A) Bending stress is caused by transverse bending moments. B) Axial stress is produced by direct tensile or compressive forces along the axis. D) Normal stress acts perpendicular to the cross section rather than tangentially.
Shortcut
Pure twisting (torsion) generates pure Shear Stress across the shaft cross-section.
Common mistake
Assuming torsional loading causes normal stress or bending stress rather than pure shear stress.
Correct answer: C) Shear Stress