A helical compression spring is wound using 2.5-mm-diameter music wire. The spring has an outside diameter of 31 mm with plain ground ends, and 14 total coils. Use the below table to choose appropriate modulus of rigidity value. Assume the maximum shear stress as 1940 MPa, dynamic loading conditions and no presetting required.
(a) Estimate the spring rate. [6 marks]
(b) What force is needed to compress this spring to closure? (c) What should the free length of the spring? (d) Is there a possibility that the spring might buckle in service? Assume operating force is 40% of force needed to compress this spring to closure.
