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In: Mechanical Engineering

For a bolted assembly with six bolts, the stiffness of each bolt is kb = 4...

For a bolted assembly with six bolts, the stiffness of each bolt is kb = 4 Mlbf/in and the stiffness of the members is km = 16 Mlbf/in per bolt. A fluctuating external load applied to the entire joint cycles between 20,000 lbf and 40,000 lbf. Assume the load is equally distributed to all the bolts. It has been determined to use 3/8 in - 16 UNC grade 8 bolts with rolled threads. Assume the bolts are preloaded to 75% of the proof load.
(a) Determine the alternating stress and mean stress carried by a bolt.
(b) Determine the fatigue factor of safety for infinite life, using the Goodman criterion and a load line that assumes the preload is carefully applied and will not vary during operation.

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samet mamat answered 2 years ago
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