skid lifting lug design
DESCRIPTION
lug designTRANSCRIPT
-
1- Loading:W = 1,700 kg Weight of component to be lifted
FS = 2 Impact factor of Safety
SWL = 35 ton shackle safe working Load
N = 1 No.s No. of Lugs
a = 90 deg. in Plane Force Angle
b = 0 deg. Out of Plane Force Angle
Wfactored = W X FS = 1700 X 2 = 3,400 kg
= 33.34 kN factored Load
Ts = W / N = 1700 / 1 = 1,700 kg Max Tension on Padeye
= 16.671 kN
P = Ts X FS = 16.671 X 2 = 33.34 kN < SWL OK
Fz = P Sin (a) = 33.343 kN Vertical Force on Padeye
Fy = P Sin (b) = 0.000 kN Out of Plan Force on Padeye
Fx = P Cos (a) = 0.000 kN Horizontal Force on Padeye
2- Dimensioning:
a- Skid Lug Sizing: Profle: W10X49
k = 70 mm Distance from lug hole to edge of beam
rL = 70 mm Lug radius
tL = 35 mm Lug thickness, tL
tcp = 12 mm Collar plate thickness, tcp
d = 62 mm Diameter of hole, d
hL = 193 mm Distance from lug hole to base, hL
wL = 253 mm Lug base width, wL
Dcp = 100 mm Collar ring diameter, Dcp
H = ( 253 )/2 - 70 = 56.50
a- Shakle Sizing:
B = 57 mm Pin Dia, Dp
A = 83 mm Shackle Clearance
C = 197 mm Shackle Depth Clearance
c- Clearance between shackle & Lug :
59 mm
A = 83 mm
tLt < A OK
rL = 70 mm
C = 197 mm
rL < C OK
OK so Lug is Acceptable
d- Lug Hole Diameter Check:
- Max of : B X 1.05 = 57 X 1.05 = 59.85 mm
or B+3 = 57 + 3.00 = 60.00 mm
Max = 60.00 mm
- Also d< (B+6) Shall be Satisfied
57 + 6.00 = 63.00 mm
60.00 < 62 < 63.00
So d is: Acceptable
3- Lifting Lug Material & Properties:
ASTM A36
Fy = 248.21 MPa Yield Strength
fby all = 0.66 Fy = 163.82 MPa Allowable bending Stress in Plane
fbz all = 0.75 Fy = 186.16 MPa Allowable bending Stress out of Plane
ft all = 0.60 Fy = 148.93 MPa Allowable tensile Stress
fbr all = 0.90 Fy = 223.39 MPa Allowable Bearing Stress
fs all = 0.40 Fy = 99.28 MPa Allowable Shear Stress
For Skid VESSEL
33.343 X Sin (90) =
33.343 X Sin (0) =
33.343 X Cos (90) =
tLT = tL + 2 X tcp = 35 + 2 X12 =
Hence Dimensions are
Material Used :
H
-
4- Stress Check at Base of Lug:
a- Bending Stresses:
My = in Plane Moment
= -6,425,120.95 N.mm
fby = in Plane Stress
= -17.21 MPa
fby < fby all
17.21 < 163.82 in Plane is: OK
Mz = (Fy X hL) Out of Plane Moment
= 0.00 N.mm
fbz = Out of Plane Stress
= 0.00 MPa
fbz < fbz all
0.00 < 186.16 out of Plane is: OK
b- Tensile Stresses:
ft =
= 0.00 MPa
ft < ft all
0.00 < 148.93 tensile is: OK
c- Combined Stresses:
U =
= 0.11 < 1.00
OK
d- Shear Stresses:
fsz = in Plane Stress
= 3.77 MPa
fsz < fs all
3.77 < 99.28 In Shear is: OK
fsy = Out of Plane Stress
= 0.00 MPa
fsy < fs all
0.00 < 99.28 Out Shear is: OK
e- Von-Mises Stresses:
fz = ft + fby = 0 + 17.21 = 17.21 MPa
fy = ft + fbz = 0 + 0 = 0.00 MPa
fxy = fsz2 + fsy
2 Average Shear Stresses
= = 3.77 MPa
fcomb =
=
=
fcomb all = 0.66 Fy = 163.82 MPa
fcomb < fcomb all
15.37 < 163.82 So: OK
( 0 X 192.7 ) =
(Fx X H)-(Fz X hL)
( 0 X 56.5 ) - ( 33342.61 X 192.7 ) =
6 My / (tL X wL2
)
6 X -6425120.95 / ( 35 X 253 ^2 ) =
fz2 + fy
2 - (fz + fy+3fxy2)
6 My / (wL X tL2 )
6 X 0 / ( 253 X 35 ^2 ) =
Fx / (tL X wL )
0/ ( 35 X 253 ) =
(17.21 / 163.82) + (0 / 186.16) + (0 / 148.93)
So Combined Stressess are:
Fz / (tL X wL )
33342.61/ ( 35 X 253 ) =
Fy / (tL X wL )
0/ ( 35 X 253 ) =
3.77^2 + 0^2
17.21^2 + 0^2 - ( 17.21 + 0 + 3X[3.77]^2 )
15.37 MPa
-
5- Stress Check at Pin Hole:
a- Tensile Stresses:
P = 33,342.61 N
At =
= [ 2 X ( 35 X (70 - 62/2) ) ] + 2 X [ 2 X ( 12 X ( (100/2) - 62/2 ) ) ]
= 3642.00 mm2
ft = P/At = 9.16 MPa
ft < ft all
9.16 < 148.93 Padeye T is: OK
b- Bearing Stresses:
Abr =
= 57 X (35 + 2 X 12 ) t cp
= 3363.00 mm2
fbr = P/Abr = 9.91 MPa t L
fbr < fbr all
9.91 < 223.39 Padeye Br is: OK t cp
B , Shackle Bolt Dia
c- Shear Stresses:
As = At & fs = ft
fs < fs all
9.16 < 99.28 Padeye S is: OK
33342.61 / 3363 = Lug Thickness
Collar Plate Thickness
[ 2 X ( tL X (rL - d/2) ) ] + 2 X [ 2 X (tcp X ( (Dcp / 2) - d/2) ) ]
33342.61 / 3642 =
B X (tL + 2tcp )
Collar Plate Thickness
At
At