Yu W., LaBoube R.A. Cold-Formed Steel Design
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WELDED CONNECTIONS 265
Figure 8.2 Standard symbols for welded joints.
8.11
trailing edge of the weld, and shearing of the sheet behind
the weld.
8.12,8.13
In addition, some welds failed in part by
peeling of the weld as the sheet material tore and deformed
out of its own plane.
An evaluation of the test results indicates that the
following equations can be used to predict the ultimate
strength of connections joined by arc spot welds.
Shear Strength of Arc Spot Welds. The ultimate shear
capacity per arc spot weld can be determined by
8.12
P
us
= A
s
τ
u
=
π
4
d
2
e
3
4
F
xx
=
3π
16
d
2
e
F
xx
(8.1)
where P
us
= ultimate shear capacity per weld, kips
A
s
= fused area of arc spot weld, in.
2
τ
u
= ultimate shear strength of weld metal, which
was taken as 0.75 F
xx
in Refs. 8.12 and
8.13, ksi
F
xx
= tensile strength of weld metal according to
strength-level designation in AWS electrode
classification, ksi
d
e
= effective diameter of fused area, in.
Based on the test data on 31 shear failures of arc spot
welds, it was found that the effective diameter of the fused
area can be computed as
8.12,8.13
d
e
= 0.7d − 1.5t ≤ 0.55d (8.2)
where d = visible diameter of outer surface of arc spot
weld
t = base thickness (exclusive of coatings) of steel
sheets involved in shear transfer
The correlation between the computed ratios of d
e
/d and
the test data is demonstrated in Fig. 8.3. Figure 8.4 shows
266 8 CONNECTIONS
Figure 8.3 Correlation between d
e
/d ratios and test data according to plate thickness.
8.13
Figure 8.4 Definitions of d, d
a
,andd
e
in arc spot welds
1.314
:
(a) single thickness of sheet; (b) double thickness of sheet.
the definitions of the visible diameter d and the effective
diameter d
e
.
Strength of Sheets Connected to a Thicker Supporting
Member by Using Arc Spot Welds. On the basis of his
analysis of stress conditions in the connected sheets around
the circumference of the arc spot weld, Blodgett pointed
out that the stress in the material is a tensile stress at the
leading edge, becoming a shear stress along the sides, and
eventually becoming a compressive stress at the trailing
edge of the weld, as shown in Fig. 8.5.
8.14,8.16, 8.96
If the
strength of welded connections is governed by transverse
tearing of the connected sheet rather than by shear failure
of the weld, the ultimate load, in kips, per weld was found
to be
P
ul
= 2.2td
a
F
u
(8.3)
where d
a
= average diameter of arc spot weld at
midthickness of t,in.;=d – t for single sheet
and =d –2t for multiple sheets (Fig. 8.4)
t = total combined base steel thickness of sheets
involved in shear transfer, in.
F
u
= specified minimum tensile strength of
connected sheets, ksi
The same study also indicated that Eq. (8.3) is applicable
only when d
a
/t ≤ 140/
√
F
u
.
For thin sheets, failure will occur initially by tension
at the leading edge, tearing out in shear along the sides,
and then buckling near the trailing edge of the arc spot
weld. By using the stress condition shown in Fig. 8.6,
Blodgett developed the following equation for determining
the ultimate load, in kips per weld
8.14,8.16
:
P
u2
= 1.4td
a
F
u
(8.4)
Equation (8.4) is applicable only when d
a
/t ≥ 240/
√
F
u
.
For 140/
√
F
u
<d
a
/t < 240/
√
F
u
, the ultimate load
per weld can be determined by the following transition
equation:
P
u3
= 0.28
1 +
960t
d
a
√
F
u
td
a
F
u
(8.5)
Figure 8.7 provides a graphic comparison of the observed
ultimate load P
uo
and the predicted ultimate load P
up
according to Eq. (8.1), (8.3), (8.4), or (8.5), whichever
is applicable.
8.12
Figure 8.8 summarizes Eqs. (8.3)–(8.5),
which govern the failure of connected sheets.
WELDED CONNECTIONS 267
Figure 8.5 Tension, compression, and shear stresses in arc spot
weld.
8.14,8.16,8.96
Figure 8.6 Tension and shear stresses in arc spot
weld.
8.14,8.16,8.96
Tensile Strength of Arc Spot Welds. In building
construction, arc spot welds have often been used for
connecting roof decks to support members such as hot-
rolled steel beams and open web steel joists. This type of
welded connection is subject to tension when a wind uplift
force is applied to the roof system.
Prior to 1989, no design information was included in the
AISI Specification to predict the tensile strength of arc spot
welds. Based on Fung’s test results
8.17
and the evaluation of
test data by Albrecht
8.18
andYuandHsiao,
8.19
the following
design equation was added in Section E2.2 of the 1989
Addendum to the 1986 edition of the AISI Specification:
P
ut
= 0.7td
a
F
u
in which P
ut
is the ultimate tensile capacity per weld in
kips. The symbols t , d
a
,andF
u
were defined previously.
The above design criterion was revised in the 1996
edition of the AISI Specification because the UMR
tests
8.66,8.67
have shown that two possible limit states may
occur. The most common failure mode is sheet tearing
around the perimeter of the weld. This failure condition
was affected by the sheet thickness, the average weld
diameter, and the material tensile strength. The nominal
Figure 8.7 Comparison of observed and predicted ultimate loads
for arc spot welds.
8.13
tensile strength of concentrically loaded arc spot welds can
be determined by the following equations depending on
the F
u
/E ratio:
1. For F
u
/E < 0.00187,
P
n
=
6.59 − 3150
F
u
E
td
a
F
u
≤ 1.46td
a
F
u
(8.6a)
2. For F
u
/E ≥ 0.00187:
P
n
= 0.70td
a
F
u
(8.6b)
In some cases, the tensile failure of the weld may occur.
The tensile strength of the arc spot weld is based on the
cross section of the fusion area and the tensile strength of
the weld metal. Therefore, for this type of failure mode, the
nominal tensile strength can be computed by Eq. (8.7):
P
n
=
πd
2
e
4
F
xx
(8.7)
where d
e
is the effective diameter of fused area and F
xx
is
the tensile strength of weld metal.
It should be noted that Eqs. (8.6) and (8.7) are subject to
the following limitations:
e
min
≥ d
F
xx
≥ 60 ksi (414 MPa, 4220 kg/cm
2
)
F
u
≤ 82 ksi(565 MPa, 5770 kg/cm
2
)
F
xx
>F
u
268 8 CONNECTIONS
Figure 8.8 Failure load for arc spot welds.
where e
min
is the minimum distance measured in the line of
force from the center line of a weld to the nearest edge of
an adjacent weld or to the end of the connected part toward
which the force is directed. Other symbols were previously
defined. When the spot weld is reinforced by a weld washer,
the tensile strength given by Eqs. (8.6a) and (8.6b) can be
achieved by using the thickness of the thinner sheet.
Equations (8.6) and (8.7) were derived from tests for
which the applied tensile load imposed a concentric load on
the spot weld, such as the interior welds on a roof system
subjected to wind uplift, as shown in Fig. 8.9. For exterior
welds which are subject to eccentric load due to wind uplift,
tests have shown that only 50% of the nominal strength can
be used for design. At a lap connection between two deck
sections (Fig. 8.9), a 30% reduction of the nominal strength
was found from the tests.
8.66,8.67
An analysis of the UMR data by LaBoube
8.97
indicated
that the nominal tensile strength could be determined based
on the ductility of the sheet, the sheet thickness, the average
weld diameter, and the material tensile strength as follows:
P
n
= 0.8
F
u
F
y
2
td
a
F
u
(8.8)
Combined Shear and Tensile Strength of Arc Spot
Welds. Based on an experimental study performed by
Stirnemann and LaBoube,
8.100
the behavior of an arc spot
weld subjected to combined shear and tension forces can
be evaluated by either Eq. (8.9) or Eq. (8.10):
P
ut
LP
nt
0.6
+
P
uv
LP
nv
≤ 1.0 (8.9)
Figure 8.9 Interior weld, exterior weld, and lap connection.
WELDED CONNECTIONS 269
where L = 1.0 for F
u
/F
y
≥ 1.23, L = 0.75 for F
u
/F
y
<
1.04, P
nt
is defined by Eq. (8.8), P
nv
is defined by Eq. (8.3),
(8.4), or (8.5), and P
ut
and P
uv
are the applied tension and
shear force,
P
ut
LP
nt
+
P
uv
LP
nv
≤ 1.0 (8.10)
where L = 1.0 for F
u
/F
y
≥ 1.23, L = 0.60 for F
u
/F
y
<
1.04, P
nt
is defined by Eq. (8.8), P
nv
is defined by Eq. (8.3),
(8.4), or (8.5), and P
ut
and P
uv
are the applied tension and
shear force.
Strength of Sheet-to-Sheet Connections Using Arc Spot
Welds. The sheet-to-sheet arc spot weld connection was
experimentally studied by Luttrell, and based on a review
of the data by LaBoube,
8.98
the nominal strength is given
by
P
n
= 1.65td
a
F
u
(8.11)
The following limits apply to the use of Eq. (8.11):
F
u
≤ 59 ksi(407 MPa, 4150 kg/cm
2
)
F
xx
>F
u
0.028 in. (0.71 mm) ≤ 0.0635 in. (1.61 mm)
8.3.1.2 Arc Seam Welds As shown in Fig. 8.10, an
arc seam weld consists of two half-circular ends and a
longitudinal weld. The ultimate load of a welded connection
is determined by the shear strength of the arc seam weld
and the strength of the connected sheets.
Shear Strength of Arc Seam Welds. The ultimate shear
capacity per weld is a combined shear resistance of two
half-circular ends and a longitudinal weld, as given by
P
us
=
3π
16
d
2
e
+
3Ld
e
4
F
xx
(8.12)
in which L is the length of the seam weld, not including the
circular ends. For the purpose of computation, L should not
exceed 3d. Other symbols were defined in the preceding
discussion.
Strength of Connected Sheets by Using Arc Seam Welds.
In the Cornell research project a total of 23 welded connec-
tions were tested for arc seam welds. Based on the study
made by Blodgett
8.14
and the linear regression analysis
performed by Pekoz and McGuire,
8.12,8.13
the following
equation has been developed for determining the strength
of connected sheets:
P
ul
= (0.625L +2.4d
a
)tF
u
(8.13)
Equation (8.13) is applicable for all values of d
a
/t.
Figure 8.11 shows a comparison of the observed loads and
the ultimate loads predicted by using Eq. (8.13).
8.3.1.3 Fillet Welds Fillet welds are often used for lap
and T-joints. Depending on the arrangement of the welds,
they can be classified as either longitudinal or transverse
fillet welds. (“Longitudinal” means that the load is applied
parallel to the length of the weld; “transverse” means that
the load is applied perpendicular to the length of the weld.)
From the structural efficiency point of view, longitudinal
fillet welds are stressed unevenly along the length of weld
due to varying deformations. Transverse fillet welds are
more uniformly stressed for the entire length. As a result,
transverse welds are stronger than longitudinal welds of
an equal length. The following discussion deals with the
strength of welded connections using both types of fillet
welds.
Shear Strength of Fillet Welds. If the strength of welded
connections is governed by the shear capacity of fillet
welds, the ultimate load per weld can be determined as
P
us
=
3
4
t
w
LF
xx
(8.14)
where t
w
= effective throat dimension
L = length of fillet weld
Figure 8.10 Arc seam weld joining sheet to supporting member.
1.314,1.345
270 8 CONNECTIONS
Figure 8.11 Comparison of observed and predicted ultimate
loads for arc seam welds.
8.13
and F
xx
was defined previously. As used in Eqs. (8.1) and
(8.12), the shear strength of the weld metal is assumed to
be 75% of its tensile strength.
Research at the University of Sydney by Teh and
Hancock
8.101
has determined that for high-strength steels
with F
y
of 65 ksi (448 MPa, 4570 kg/cm
2
) or higher the
weld throat failure does not occur in materials less than
0.10 in. (25.4 mm) thick and the AISI North American spec-
ification provisions based on sheet strength are satisfactory
for materials less than 0.10 in. (25.4 mm) thick.
Strength of Connected Sheets by Using Fillet Welds
1. Longitudinal Welds. A total of 64 longitudinal
fillet welds were tested in the Cornell study.
8.12,8.13
An evaluation of the test data indicated that the
following equations can predict the ultimate loads of
the connected sheets for the failure involving tearing
along the weld contour, weld shear, and combinations
of the two types of failure:
P
ul
=
1 − 0.01
L
t
tLF
u
for L/t < 25 (8.15a)
P
u2
= 0.75tLF
u
forL/t > 25 (8.15b)
in which P
u1
and P
u2
are the predicted ultimate
loads per fillet weld. Other symbols were defined
previously.
2. Transverse Welds. Based on the results of 55 tests on
transverse fillet welds, it was found that the primary
failure was by tearing of connected sheets along, or
Figure 8.12 Comparison of observed and predicted ultimate
loads for longitudinal fillet welds.
8.13
close to, the contour of the welds. The secondary
failure was by weld shear. The ultimate failure load
per fillet weld can be computed as
P
u3
= tLF
u
(8.16)
Figures 8.12 and 8.13 show comparisons of the observed
and predicted ultimate loads for longitudinal and transverse
fillet welds, respectively.
8.3.1.4 Flare Groove Welds In the Cornell research, 42
transverse flare bevel welds (Fig. 8.14) and 32 longitudinal
flare bevel welds (Fig. 8.15) were tested. It was found
that the following formulas can be used to determine the
predicted ultimate loads.
Shear Strength of Flare Groove Welds. The ultimate
shear strength of a flare groove weld is
P
us
=
3
4
t
w
LF
xx
(8.17)
The above equation is similar to Eq. (8.14) for fillet welds.
Strength of Connected Sheets by Using Flare Groove
Welds. If the strength of weld connections is governed
by the connected sheets, the ultimate load per weld can be
determined as follows:
1. Transverse Welds
P
ul
= 0.833tLF
u
(8.18)
WELDED CONNECTIONS 271
Figure 8.13 Comparison of observed and predicted ultimate
loads for transverse fillet welds.
8.13
Figure 8.14 Transverse flare bevel weld.
1.314,1.345
2. Longitudinal Welds. If t ≤ t
w
< 2t or if the lip height
is less than the weld length L,
P
u2
= 0.75tLF
u
(8.19)
If t
w
≥ 2t and the lip height is equal to or greater
than L,
P
u3
= 1.5tLF
u
(8.20)
Figures 8.16 and 8.17 show comparisons of the observed
and predicted ultimate loads for transverse and longitudinal
flare bevel welds, respectively.
8.3.2 AISI Design Criteria for Arc Welds
8.3.2.1 Thickness Limitations In previous editions of
the AISI Specifications, the design provisions have been
Figure 8.15 Longitudinal flare bevel weld.
1.314,1.345
Figure 8.16 Comparison of observed and predicted ultimate
loads for transverse flare bevel welds.
8.13
used for cold-formed members and thin elements with
a maximum thickness of
1
2
in. (12.7 mm). Because the
maximum material thickness for using the AISI Specifi-
cation was increased to 1 in. (25.4 mm) in 1977
8.21
and
the structural behavior of weld connections for joining
relatively thick cold-formed members is similar to that of
hot-rolled shapes, Section E2 of the AISI North American
Specification is intended only for the design of arc welds
for cold-formed steel members with a thickness of
3
16
in.
(4.76 mm) or less.
1.134
When the connected part is over
3
16
in. (4.76 mm) in thickness, arc welds can be designed
according to the AISC specification.
1.148,3.150
8.3.2.2 Criteria for Various Weld Types Section 8.3.1
discussed ultimate strengths of various weld types. The
272 8 CONNECTIONS
Figure 8.17 Comparison of observed and predicted ultimate
loads for longitudinal flare bevel welds.
8.13
ultimate load P
u
determined in Section 8.3.1 for a given
type of weld is considered to be the nominal strength of
welds, P
n
, used in Section E2 of the AISI North American
Specification. The following are the AISI design provisions
for groove welds used in butt joints, arc spot welds, arc
seam welds, fillet welds, and flare groove welds.
Groove Welds in Butt Joints. For the design of groove
welds in butt joints (Fig. 8.1a), the nominal strength P
n
and the applicable safety factor and resistance factor are
giveninSectionE2.1oftheAISISpecificationasfollows:
a. Tension or Compression Normal to Effective Area or
ParalleltoAxisofWeld
P
n
= Lt
e
F
y
(8.21)
= 1.70 (ASD)
φ =
0.90 (LRFD)
0.80 (LSD)
b. Shear on Effective Area. Use the smaller value of either
Eq. (8.22) or (8.23):
P
n
= Lt
e
(0.6F
xx
) (8.22)
= 1.90 (ASD)
φ =
0.80 (LRFD)
0.70 (LSD)
P
n
=
Lt
e
F
y
√
3
(8.23)
= 1.70 (ASD)
φ =
0.90 (LRFD)
0.80 (LSD)
where P
n
= nominal strength (resistance) of groove
weld
F
xx
= tensile strength electrode classification
F
y
= yield stress of the lowest strength base
steel
L = length of weld
t
e
= effective throat dimension of groove weld
Equations (8.21), (8.22), and (8.23) are the same as
the AISC LRFD Specification.
3.150
The effective throat
dimensions for groove welds are shown in Fig. 8.18.
Arc Spot Welds (Puddle Welds). Section E2.2 of the
AISI North American specification includes the following
requirements for using arc spot welds:
1. Arc spot welds should not be made on steel where
the thinnest connected part is over 0.15 in. (3.81 mm)
thick or through a combination of steel sheets having
a total thickness of over 0.15 in. (3.81 mm).
2. Weld washers should be used when the thickness
of the sheet is less than 0.028 in. (0.711 mm). Weld
washers should have a thickness of between 0.05
(1.27 mm) and 0.08 in. (2.03 mm) with a minimum
prepunched hole of
3
/
8
in. (9.53 mm) diameter.
Figure 8.18 Effective dimensions for groove welds.
WELDED CONNECTIONS 273
3. The minimum allowable effective diameter d
e
is
3
/
8
in. (9.5 mm).
4. The distance measured in the line of force from the
centerline of a weld to the nearest edge of an adjacent
weld or to the end of the connected part toward which
the force is directed should not be less than the value
of e
min
as given below:
e
min
=
⎧
⎪
⎪
⎨
⎪
⎪
⎩
P
F
u
t
(ASD) (8.24)
P
u
φF
u
t
(LRFD and LSD) (8.25)
i. When F
u
/F
sy
≥ 1.08,
= 2.20 (ASD)
φ =
0.70 (LRFD)
0.60 (LSD)
ii. When F
u
/F
sy
< 1.08,
= 2.55 (ASD)
φ =
0.60 (LRFD)
0.50 (LSD)
where P = required shear strength (nominal force)
transmitted by the weld (ASD)
P
u
= required shear strength (factored shear
load) transmitted by the weld (LRFD or
LSD)
t = thickness of thinnest connected sheet
F
u
= tensile strength of steel
F
sy
= yield point of steel
5. The distance from the centerline of any weld to the
end or boundary of the connected member should not
be less than 1.5d . In no case should the clear distance
between welds and end of member be less than 1.0d.
6. The nominal shear strength P
n
of each arc spot
weld between sheet or sheets and supporting member
should not exceed the smaller value of the loads
computed by Eqs. (8.26) and (8.27):
i. Nominal Shear Strength Based on Shear Capacity
of Weld
P
n
=
πd
2
e
4
(0.75F
xx
) (8.26)
= 2.55 (ASD)
φ =
0.60 (LRFD)
0.50 (LSD)
ii. Nominal Shear Strength for Sheets of Connected to
Thicker Member
a. For d
a
/t ≤ 0.815
√
E/F
u
,
P
n
= 2.20td
a
F
u
(8.27a)
= 2.20 (ASD)
φ =
0.70 (LRFD)
0.60 (LSD)
b. For 0.815
√
E/F
u
<(d
a
/t) < 1.397
√
E/F
u
,
P
n
= 0.280
1 + 5.59
√
E/F
u
d
a
/t
td
a
F
u
(8.27b)
= 2.80 (ASD)
φ =
0.55 (LRFD)
0.45 (LSD)
c. For d
a
/t ≥ 1.397
√
E/F
u
,
P
n
= 1.40td
a
F
u
(8.27c)
= 3.05 (ASD)
φ =
0.50 (LRFD)
0.40 (LSD)
In the above requirements and design formulas
for arc spot welds,
P
n
= nominal shear strength of an arc spot weld
d = visible diameter of outer surface of arc spot
weld (Fig. 8.4)
d
a
= average diameter of arc spot weld at mid
thickness of t (Fig. 8.4), =d – t for a
single sheet and =d –2t for multiple
sheets (not more than four lapped sheets
over a supporting member)
d
e
= effective diameter of fused area (Fig. 8.4),
=0.7d–1.5t but ≤ 0.55d
t = total combined base steel thickness
(exclusive of coating) of sheets involved in
shear transfer above the plane of maximum
shear transfer
F
xx
= filler metal strength designation in AWS
electrode classification
F
u
= specified minimum tensile strength of steel
iii. Nominal Shear Strength for Sheet-to-Sheet Connec-
tions
P
n
= 1.65td
a
F
u
(8.28)
= 2.20 (ASD)
φ =
0.70 (LRFD)
0.60 (LSD)
274 8 CONNECTIONS
7. The nominal tensile strength P
n
of each concentrically
loaded arc spot weld connecting sheets and supporting
members should be the smaller value of the loads
computed by Eqs. (8.29) and (8.30):
i. Nominal Tensile Strength Based on Capacity of
Weld
P
n
=
1
4
πd
2
e
F
xx
(8.29)
ii. Nominal Tensile Strength Based on Strength of
Connected Sheets
P
n
= 0.80
F
u
F
y
2
td
a
F
u
(8.30)
For panel and deck applications for both Eqs. (8.29)
and (8.30),
= 2.50 (ASD)
φ =
0.60 (LRFD)
0.50 (LSD)
For other applications for both Eqs. (8.29) and (8.30),
= 3.00 (ASD)
φ =
0.50 (LRFD)
0.40 (LSD)
Both Eqs. (8.29) and (8.30) are limited to the following
conditions: td
a
F
u
≤ 3kips(13.34 kN), e
min
≥ d,F
xx
≥
60 ksi (410 MPa, 4220 kg/cm
2
), F
u
≤ 82 ksi (565 MPa,
5770 kg/cm
2
) (of connecting sheets), and F
xx
>F
u
.All
symbols were defined previously.
It should be noted that Eq. (8.26) is derived from Eq.
(8.1). Equations (8.27a), (8.27b), and (8.27c) are based on
Eqs. (8.3), (8.5), and (8.4), respectively. These equations
are also shown in Fig. 8.8. The background information on
tensile strength was discussed previously.
Example 8.1 Use the ASD and LRFD methods to deter-
mine the allowable load for the arc spot welded connection
shown in Fig. 8.19. Use A1011 Grade 45 steel (F
y
= 45 ksi,
F
u
= 60 ksi). Assume that the visible diameter of the arc
spot weld is
3
4
in. and the dead load–live load ratio is
1
5
.
SOLUTION
A. ASD Method.
Prior to determination of the allowable load, the AISI
requirements for using arc spot welds are checked as
follows:
1. Since the thickness of the connected sheets is less than
0.15 in., arc spot welds can be made.
2. Because the thickness of the connected sheets is over
0.028 in., weld washers are not required.
3. The visible diameter d is
3
4
in., and
d
a
= d − t = 0.75 − 0.075 = 0.675 in.
d
e
= 0.7d − 1.5t = 0.70(0.75) − 1.5(0.075)
= 0.4125 in. = 0.55d
Use
d
e
= 0.4125 in. >
3
8
in. (minimum size) OK
4. The distance from the centerline of any weld to the
end of the sheet is
1.25 in. >(1.5d = 1.125 in.) OK
5. The clear distance between welds is
2 − d = 1.25 in. >d OK
The clear distance between welds and end of
member is
1.25 −
1
2
= 0.875 in. >d OK
6. The allowable load for the ASD method is based on
the following considerations:
a. Tensile Load for Steel Sheets. BasedonSectionC2
of the AISI specification:
(i) For yielding [Eq. (6.2)],
P
al
=
T
n
t
=
A
g
F
y
1.67
=
(4.5 × 0.075)(45)
1.67
= 9.09 kips
(ii) For fracture away from the connection [Eq.
(6.3)],
P
a1
=
T
n
t
=
A
n
F
u
2.00
=
(4.5 × 0.075)(60)
2.00
= 10.125 kips
Use P
a1
= 9.09 kips.
b. Tensile Load Based on End Distance (e = 1.25 in.)
F
u
F
y
=
60
45
= 1.33 > 1.08
By using Eq. (8.24),
P
a2
= 4P =
4e(F
u
t)
2.20
=
4(1.25)(60)(0.075)
2.20
= 10.23 kips