Timothy A. Philpot - Mechanics of materials _ an integrated learning system-John Wiley (2017)

The design strength is the product of the nominal strength and the resistance factor for this
type of component (i.e., a tension member). The design strength must equal or exceed the
factored load acting on the member:
φ P
≥ P
t n u
Thus, the cross-sectional area required to support the given loading is
φ P = φσ A ≥ P
t n t Y u
Pu
112.8 kips
2
∴ A ≥ = = 3.48 in.
Ans.
φσ 0.9(36 ksi)
t
Y
pRobLEMS
p4.13 A 25 mm thick steel plate will be used as an axial member
to support a dead load of 280 kN and a live load of 410 kN. The
yield strength of the steel is 250 MPa.
(a) Use the ASD method to determine the minimum plate width b
required for the axial member if a factor of safety of 1.67 with
respect to yielding is required.
(b) Use the LRFD method to determine the minimum plate width
b required for the axial member on the basis of yielding of the
gross section. Use a resistance factor φ t = 0.9 and load factors
of 1.2 and 1.6 for the dead and live loads, respectively.
p4.14 A round steel tie rod is used as a tension member to support
a dead load of 90 kN and a live load of 120 kN. The yield
strength of the steel is 320 MPa.
(a) Use the ASD method to determine the minimum diameter
required for the tie rod if a factor of safety of 2.0 with respect
to yielding is required.
(b) Use the LRFD method to determine the minimum diameter
required for the tie rod on the basis of yielding of the gross
section. Use a resistance factor φ t = 0.9 and load factors of
1.2 and 1.6 for the dead and live loads, respectively.
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