1. What is Shaft Twist?

Shaft twist (θ) is the angular deformation that occurs when a torque is applied to a shaft. It's a measure of how much a shaft rotates along its length when subjected to torsional stress.

2. How Does the Calculator Work?

The calculator uses the shaft twist equation:

Where:

• \( \theta \) — Angle of twist (radians)
• \( T \) — Applied torque (N·m)
• \( L \) — Length of shaft (m)
• \( G \) — Shear modulus of material (Pa)
• \( J \) — Polar moment of inertia (m⁴)

Explanation: The equation shows that twist angle is directly proportional to torque and length, and inversely proportional to shear modulus and polar moment of inertia.

3. Importance of Shaft Twist Calculation

Details: Calculating shaft twist is essential for designing mechanical systems to ensure shafts can handle applied torques without excessive deformation that could lead to failure or misalignment.

4. Using the Calculator

Tips: Enter torque in N·m, length in meters, shear modulus in Pascals, and polar moment of inertia in m⁴. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for shear modulus (G)?
A: For steel, G ≈ 79.3 GPa; for aluminum, G ≈ 26 GPa; for brass, G ≈ 39 GPa.

Q2: How do I calculate polar moment of inertia (J)?
A: For a solid circular shaft, J = πd⁴/32 where d is diameter. For hollow shafts, J = π(d_o⁴-d_i⁴)/32.

Q3: What's an acceptable twist angle?
A: This depends on application, but typically less than 1° per meter for precision machinery.

Q4: Does this equation work for non-circular shafts?
A: No, this equation is specifically for circular shafts. Non-circular sections require more complex calculations.

Q5: How does temperature affect the results?
A: Shear modulus decreases with increasing temperature, which would increase twist angle for the same torque.