Torsion refers to the twisting of a shaft when a torque or twisting moment acts on it. The angle of twist is defined as the angle through which the shaft's cross section rotates due to the torque. Torque causes rotation, while torsion is the effect produced by torque. Torsion occurs in a shaft when it is subjected to two equal and opposite twisting moments, known as pure torsion. The torsion equation relates the angle of twist in a shaft to the applied torque based on certain assumptions about the shaft's material properties and dimensions. Power can be transmitted through a rotating shaft by applying torque that causes torsion.

1. TORSION
Concept of Torsion
Difference between TORQUE and TORSION
Use of TORSION Equation for circular shaft
Power transmitted by shaft
Related Numerical Problem
By:-
Er. Bharat Bansal
Lect. Mechanical Engineering
Govt. Polytechnic College Bathinda

2. TORSION
• Twisting of a shaft
• Occurs when Torque or Twisting moment acts
on the shaft

3. ANGLE OF TWIST
• The angle through which the cross section of
the shaft is rotated by action of twisting
moment or torque.

4. Difference between TORQUE and
TORSION
TORQUE TORSION
Definition Rotation effect of Force Effect produced due to Torque
Measurement Possible Not Possible
SI unit Newton-meter No physical unit available,
Measured through angle of twist

5. PURE TORSION
• If shaft is subjected to two equal and opposite
twisting moments only, then it is said to be in
pure torsion or simple torsion.

6. ASSUMPTIONS IN THEORY OF PURE TORSION

7. TORSION EQUATION

8. POWER TRANSMITTED BY A SHAFT