Estimate the maximum stress in the wire at critical point B.

1.A round wire helical-coil tension spring has end loops of the type shown in Figures 14.7(a) and (b). The wire diameter of the spring is 0.042 inch, and the mean coil radius is 0.28 inch. Pertinent end-loop dimensions are riA 0.25 inch and riB 0.094 inch. An applied axial static tension force of F 5.0 lb is to be applied to the spring.

a. Estimate the maximum stress in the wire at critical point A.

b. Estimate the maximum stress in the wire at critical point B.

c. If the spring wire is ASTM A227 material, and a safety factor of 1.25 is desired, would the stresses at critical points A and B be acceptable?