2) The extension spring shown in figure has full-twisted loop ends. The material is BS 5216 Grade 2. The spring has 84 coils and is close-wound with a preload Inside dia. 50 mm of 80 N. a) Find the closed length of the spring. b) Find the torsional stress in the spring corresponding to the preload. 5 mm c) Estimate spring rate. 5 mm d) What load would cause permanent deformation? e) What is the spring deflection corresponding to the load found in part Running length= 100 mm Assembled length= 180 mm Free length= 200 mm

A helical compression spring is needed to fit over a 0.5 in. diameter rod. To allow for some clearance, the inside diameter of the spring is to be 0.6 in. To ensure a reasonable spring size, assume a spring index of 10. The spring is to be used in a machine where it will be repeatedly compressed from a free length of 5 in. to its solid length of 2 in. and then released. The spring should have squared and ground ends and is to be made from a cold-drawn A227 wire. (a) Determine a suitable wire diameter. (b) Determine a suitable total number of coils. (c) Determine the spring rate. (d) Where is the maximum stress in the wire of the spring? (e) Determine the static factor of safety when compressed to its solid length. (f) If the spring is to be designed for infinite life, what will be the mean stress and alternating stress on the spring. (g) Calculate the weight of the spring.

2) The extension spring shown in figure has full-twisted loop ends. The material is BS 5216 Grade 2. The spring has 84 coils and is close-wound with a preload of 80 N. 6 mm a) Find the closed length of the spring. 40 mm b) Find the torsional stress in the spring corresponding to the preload. 18 mm 10 mm c) Estimate spring rate. d) What load would cause permanent deformation? e) What is the spring deflection corresponding to the load found in part

! Required information A helical compression spring is made of hard-drawn spring steel wire of diameter 0.0773in. and has an outside diameter of 0.85 in. The ends are plain and ground, and there are 8 coils. NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. Will the spring buckle in service? The value of (LO)cr is