Question

In: Mechanical Engineering

1. Suppose there a joint where the bolts have a stiffness of 1638 kips/in per bolt...

1. Suppose there a joint where the bolts have a stiffness of 1638 kips/in per bolt and the members have a stiffness of 10930 kips/in per bolt. The bolts are ½-13 UNC, SAE 8 grade, installed for non-permanent installation. The maximum load is 14 kips per bolt. For the fatigue calculation, consider that the minimum load is zero.

a) What is the stiffness constant, C, of the joint?

b) What is the proof load, SpAt, of the bolt, in kips?

c) What is the pre-load, Fi, on the bolt, in kips?

d) What is the factor of safety in yield, np?

e) What is the load factor of safety, nL?

f) What is the joint separation factor of safety, nO?

g) What is the midrange stress, sm, in kpsi?

h) What is the amplitude stress, sa, in kpsi?

i) What is the initial stress, si, in kpsi?

j) What is the fatigue factor of safety, nf?

k) Is this joint safe in both static and fatigue loading?

2. If the ½-13 UNC, SAE 8 grade bolts from the previous problem are zinc-plated and eight of them are used on a 6 in. bolt circle,

a) What is the minimum number of these bolts that should be applied to this bolt circle?

b) What is the maximum number of these bolts that should be applied to this bolt circle?

c) Are eight bolts an appropriate number here?

d) What is the torque required to make up the bolts to the required pre-load, in in-kips?

e) What torque would be required to make up the bolts for permanent installation, in in-kips?

Expert Solution

Thank you.

samet mamat answered 1 year ago

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