Question

A close-coiled helical spring has a wire diameter of 2.5 mm and a mean coil diameter of 4Omm. The
spring is subjected to a combined axial load of 60N and a torque acting about the axis of the spring. determine the
maximum permissible torque if (a) the material is brittle and ultimate failure is to beavoided, the criterion of failure is
the maximum tensile stress, and the ultimate tensile stress is 1.2 GN/m2, (b) the material is ductile and failure by
yielding is to be avoided, the criterion of failure is the maximum shear stress, and the yield in tension is 0.9 GN/m2.

Answer 1