An open-coiled helical spring of wire diameter 12 mm, mean coil radius 84 mm, helix angle 60° carries an axial load of 480 N. What is the twisting moment ?

Question

Question

This question was previously asked in

ESE Civil 2021 Official Paper

Answer 1

Explanation:

Given Data

Wire diameter(d) = 12 mm

Mean coil radius(R) = 84 mm

Angle of helix () = 60⁰

Axial Load (W) = 480 N

Now the twisting moment(T) due to the axial load acting on an open-coiled helical spring is given by

N-mm

T= 20.16 N-m

Additional Information The axial load acting on an open-coiled helical spring, bending moment(M) is given by

The Strain energy in open-coiled helical spring due to axial load given by

Strain energy = Strain energy due to bending + Strain energy due to torsion