Angle of Twist Calculator

Calculate the angle of twist in circular shafts subjected to torsional loading

Calculate Angle of Twist

m

Calculation Results

0.0000
Angle of Twist (°)
0.00
Polar Moment (mm⁴)

Formula used: φ = TL/(JG)

Max shear stress: 0.00 MPa

Twist per unit length: 0.000000 rad/m

Engineering Analysis

Example Calculation

Aluminum Shaft Example

Material: Aluminum 6061-T6 (G = 26 GPa)

Shaft diameter: 100 mm (solid circular)

Shaft length: 3 m

Applied torque: 10 kN·m

Solution Steps

1. Polar moment: J = πD⁴/32 = π(0.1)⁴/32 = 9.82 × 10⁻⁶ m⁴

2. Angle of twist: φ = TL/(JG) = (10,000 × 3)/(9.82 × 10⁻⁶ × 26 × 10⁹)

3. Result: φ = 0.117 rad = 6.73°

Material Properties

Aluminum27 GPa
Aluminum26 GPa
Gray27 GPa
Malleable68 GPa
Red37 GPa
Bronze38 GPa
Magnesium18 GPa
Structural75 GPa

Key Formulas

Angle of Twist

φ = TL/(JG)

Solid Circular

J = πD⁴/32

Hollow Circular

J = π(D⁴-d⁴)/32

Max Shear Stress

τ = Tr/J

Understanding Angle of Twist

What is Angle of Twist?

The angle of twist is the relative rotation between two cross-sections of a shaft when subjected to torsional loading. It represents how much one end of the shaft rotates relative to the other end due to applied torque.

Key Parameters

  • Torque (T): Applied twisting moment
  • Length (L): Distance between cross-sections
  • Polar Moment (J): Geometric property of cross-section
  • Shear Modulus (G): Material property resisting shear deformation

Mathematical Foundation

φ = TL/(JG)

Basic torsion formula

τ = Gγ = Tr/J

Shear stress-strain relationship

Assumptions:

  • • Circular cross-section
  • • Uniform material properties
  • • Linear elastic behavior
  • • Constant torque along length
  • • Plane sections remain plane

Engineering Applications

Power Transmission

  • • Drive shafts
  • • Propeller shafts
  • • Motor shafts
  • • Turbine shafts

Structural Design

  • • Building columns
  • • Bridge members
  • • Tower structures
  • • Framework elements

Mechanical Systems

  • • Gear systems
  • • Coupling design
  • • Spring systems
  • • Tool design