1. Suppose there a joint where the bolts have a stiffness of1638 kips/in per bolt and the members have a stiffness of 10930kips/in per bolt. The bolts are ½-13 UNC, SAE 8 grade, installedfor non-permanent installation. The maximum load is 14 kips perbolt. For the fatigue calculation, consider that the minimum loadis 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 problemare zinc-plated and eight of them are used on a 6 in. boltcircle,
a) What is the minimum number of these bolts that should beapplied to this bolt circle?
b) What is the maximum number of these bolts that should beapplied to this bolt circle?
c) Are eight bolts an appropriate number here?
d) What is the torque required to make up the bolts to therequired pre-load, in in-kips?
e) What torque would be required to make up the bolts forpermanent installation, in in-kips?
