A helical compression spring shown in figure, experience a minimum force of 150 1b at just before ignition. During the working cycle it experiences addition force as it is compressed by an inch. The spring rate is 50 lb/in. The coil must fit in a 2.1-in-dia hole with 0.1 in clearance. Use 0.25 in diameter, peened, OQ&T wire and squared/ground ends. Find a) The stresses and safety factor for infinite life fatigue. b) Calculate the number of the coils. (Shear modulus G=11.5 x10^6 psi) Note that for peened springs, Zimmerli's finding is updated as follows: Ssa = 57.5 kpsi (398 MPa) and Ssm = 77.5 kpsi (534 MPa)

A helical compression spring shown in figure, experience a minimum force of 150 1b at just before ignition. During the working cycle it experiences addition force as it is compressed by an inch. The spring rate is 50 lb/in. The coil must fit in a 2.1-in-dia hole with 0.1 in clearance. Use 0.25 in diameter, peened, OQ&T wire and squared/ground ends. Find a) The stresses and safety factor for infinite life fatigue. b) Calculate the number of the coils. (Shear modulus G=11.5 x10^6 psi) Note that for peened springs, Zimmerli's finding is updated as follows: Ssa = 57.5 kpsi (398 MPa) and Ssm = 77.5 kpsi (534 MPa)

Mechanics of Materials (MindTap Course List)

9th Edition

ISBN:9781337093347

Author:Barry J. Goodno, James M. Gere

Publisher:Barry J. Goodno, James M. Gere

Chapter2: Axially Loaded Members

Section: Chapter Questions

Problem 2.5.31P

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