Torsion of shafts worksheet with answers

Free printable Torsion of shafts worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
N = 300 rpmT = ?

A motor delivers 30 kW to a shaft turning at 300 rpm. Find the torque T in the shaft.

P = 30 kWN = 300 rpm
T = N·m
2.Easy
T = 100 N·md = 20 mm

A solid circular shaft carries a torque T. Find the maximum shear stress τmax in the shaft.

T = 100 N·md = 20 mm
τmax = MPa
3.Medium
do​ = ?T = 400 N·m

A hollow shaft must carry a torque of 400 N·m. Its inner diameter is to be 0.6 times its outer diameter, and the shear stress must not exceed 50 MPa. Find the smallest outer diameter do.

T = 400 N·mdi/do = 0.6τallow = 50 MPa
do = mm
4.Medium
d = 15 mmT = 40 N·m200 mmφ = 2.36°

In a torsion test, a solid specimen of diameter 15 mm is twisted by a torque of 40 N·m. The two ends of a gauge length of 200 mm rotate 2.36° relative to each other (the material is still elastic). Find the shear modulus G of the material.

T = 40 N·md = 15 mmL = 200 mmφ = 2.36°
G = GPa
5.Hard
Td = ?

A solid shaft must transmit 5 kW at 1500 rpm without the shear stress exceeding 40 MPa. Find the smallest diameter d that works.

P = 5 kWN = 1500 rpmτallow = 40 MPa
d = mm
6.Hard
d = 60 mmTB​ = 500 N·mTC​ = 200 N·mABC2.5 m2 m

A solid steel shaft of diameter 60 mm is fixed at A. A torque of 500 N·m acts at B, 2.5 m from A, and a torque of 200 N·m in the opposite direction acts at the free end C, a further 2 m along. Find the maximum shear stress τmax in the shaft.

d = 60 mmTB = 500 N·mTC = 200 N·mAB = 2.5 mBC = 2 m
τmax = MPa

Answer key

  1. 1. T = 954.9 N·m
  2. 2. τmax = 63.66 MPa
  3. 3. do = 36.04 mm
  4. 4. G = 39.08 GPa
  5. 5. d = 15.94 mm
  6. 6. τmax = 7.074 MPa

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