Question

An open-coiled helical spring of mean diameter D, number of coils N and wire diameter d is subjected to an axial force P. The wire of the spring will be subjected to-

• A. Direct shear only
• B. Combined shear and bending only
• C. Combined shear, bending and twisting
• D. Combined shear and twisting only

Answer 1

The correct option is C Combined shear, bending and twisting

In an open coiled spring, the helix angle $\alpha$ is greater than ${10}^{\circ }$. Let it be $\alpha$.

It can be seen that the section of the spring is subjected to twisting couple $\frac{PD}{2}cos\alpha ,bendingcouple\frac{PD}{2}sin\alpha anddirectshearP.$