Page 492 - Shigley's Mechanical Engineering Design

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Screws, Fasteners, and the Design of Nonpermanent Joints 467
(c) Determine the factor of safety based on joint separation.
(d) Determine the fatigue factor of safety using the Goodman criterion.
8–50 For the bolted assembly in Prob. 8–32, assume 10 bolts are used. Determine the fatigue factor
of safety using the Goodman criterion.
8–51 to For the pressure cylinder defined in the problem specified in the table, the gas pressure is cycled
8–54 between zero and p g. Determine the fatigue factor of safety for the bolts using the following
failure criteria:
(a) Goodman.
(b) Gerber.
(c) ASME-elliptic.

Originating
Problem Problem
Number Number

8–51 8–33
8–52 8–34
8–53 8–35
8–54 8–36

8–55 to For the pressure cylinder defined in the problem specified in the table, the gas pressure is cycled
8–58 between p g and p g /2. Determine the fatigue factor of safety for the bolts using the Goodman
criterion.

Originating
Problem Problem
Number Number
8–55 8–33
8–56 8–34
8–57 8–35
8–58 8–36

8–59 A 1-in-diameter hot-rolled AISI 1144 steel rod is hot-formed into an eyebolt similar to that shown
in the figure for Prob. 3–122, with an inner 3-in-diameter eye. The threads are 1 in-12 UNF and
are die-cut.
(a) For a repeatedly applied load collinear with the thread axis, using the Gerber criterion, is
fatigue failure more likely in the thread or in the eye?
(b) What can be done to strengthen the bolt at the weaker location?
(c) If the factor of safety guarding against a fatigue failure is n f = 2, what repeatedly applied
load can be applied to the eye?
8–60 The section of the sealed joint shown in the figure is loaded by a force cycling between 4
and 6 kips. The members have E = 16 Mpsi. All bolts have been carefully preloaded to F i =
25 kip each.