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STANDARD LIFTING LUG DESIGN 5 TONS CAPACITY

Generals Data: Number of lug, NL

=

1.0

Safety Factor, SF Pad Eye Load / Weight, WSWL

=

2.00

=

5 Ton

Angle, α of Load with Vertical

=

60.0 deg

=

1.05 rad

Out of Plane Angle Ø

=

5.0 deg

=

0.09 rad

Dynamic Load Factor DLF (Table 1)

=

2.0

Design Load Load in vertical force, Pz = WSWL COS α

=

2.50 Ton

=

5512 lbs

Load in horizontal force (in-plane), Py = WSWL sinα.cosØ

=

4.31 Ton

=

9510 lbs

Load in lateral force (out-of-plane), Px = WSWL sinα.sinØ Max tension force in sling, Fsl = (Fz2 + Fy2 + Fx2)0.5

=

0.38 Ton

=

832 lbs

=

5.00 Ton

=

11023 lbs

Pad Eye Design Load Pd = P x DLF Design Load in Vertical Direction, PzD = Pz x DLF

=

10 Ton

=

22046 lbs

=

5 Ton

=

11023 lbs

Design Load in horizontal force (in-plane), PyD = Pz x DLF

=

9 Ton

=

19020 lbs

Design Load in lateral force (out-of-plane), P xD = Pz x DLF+ 5% Pd

=

1 Ton

=

2766 lbs

Shackles Data: (Shackle Crosby G-2130 7/8"" 6 1/2 T WLL) Check R > 1.25 DH Shackle working load limit, WLLs

= =

6.50 Ton

=

14330 lbs

Safety factor of shackle, SFs

=

Shackle max. proof load, MPLs

=

13.00 Ton

=

28660 lbs

Pin diameter, DP

=

25 mm

=

1.00 in

Jaws width, WJ

=

=

1.44 in

Jaws height, HJ

=

37 mm 84 mm

=

3.31 in

Sling Data: (5T WLL) Diameter of sling, Ds

=

16 mm 1490 N 34.2 Ton

=

0.63 in

Minimum Breaking Force, P Working Load Limit, WLLsl = 75% x 1.5P / (5 x 9.81)

= = P

Safety factor of sling, SFsl Sling ultimate load, Usl

OK

2.0

=

lbs

=

75341 lbs 301363 lbs

=

4.0

=

137 Ton

=

=

155 mm 80 mm

=

6.10 in

=

3.15 in

150 mm 75 mm 35 mm 15 mm 0 mm 0 mm

=

5.91 in

= = = = =

2.95 1.38 0.59 0.00 0.00 38.46%

PZ

α

R PY

Ø DH

HT Z

X

HH

PX

Y

Lug Dimensions: Total Height of lift lug, HT

WL

Height of hole centreline, HH

=

Width of lug, WL

=

Radius of lug, R Diameter of hole, DH Thickness of lug, tL

= = = = =

Radius of cheek, r Thickness of cheek, tC Check shackle strength, Fsl / MPLs

in in in in in

=

Safe

Ratio

=

Check sling strength, Fsl / Usl

=

Safe

Ratio

=

3.66%

Check space of hole and pin, Dp / DH

=

Clear

Ratio

=

72.57%

Dp - DH

=

Check space of jaws and lug thickness, tL+2tC / WJ

=

Clear

Ratio

=

40.98%

(WJ - tL - 2 tC)/2 Check space of jaws, lug height and dia. of sling HJ - R - 1.5Ds + DH/2

= = =

10.80 mm Clear Ratio 2.50 mm

= = =

0.43 in 97.02% 0.10 in

Material, Stress and Properties Data: Lug material Yield stress, Sy

= =

A-36 248.21 MPa

=

36000 psi

Allowable stress based on AISC Code 9th Ed. : Allow. Tensile Stress, Sta = 0.6 Sy Allow. Tensile Stress at pin hole, Stp = 0.45 Sy Allow. Bending Stress, Sba = 0.66 Sy (In-Plane) Allow. Bending Stress, Sbao = 0.66 Sy (out of-plane) Allow. Shear Stress, Ssa = 0.4 Sy Allow. Bearing Stress, Sbra = 0.9 Sy Allow. Von Misses Stress, Sx = 0.75 Sy Allow. Hertz Stress,(at Pin Hole) SH = 2.5 Sy

= = = = = = = =

148.93 111.70 163.82 163.82 99.28 223.39 186.16 620.53

= = = = = = = =

21600 16200 23760 23760 14400 32400 27000 90000

DH/2R

=

0.23

9.60 mm

Page 3

MPa MPa MPa MPa MPa MPa MPa MPa

=

0.38 in

psi psi psi psi psi psi psi psi

Table 1. API RP 2A WSD Sec.2.4.2.c LIFT TYPE

DLF

Lift as Open Sea

2.0

Lift at Sheltered Locations

1.5

Stress-Concentration factor (near hole), K (2) (for flat plate with centrally located circular hole in tension based on DH/2R value) Section modulus of lugs, SLy = tL2 WL / 6 Section modulus of lugs, SLx = tL WL2 / 6

= = =

2.50 5.63 cm3 56.25 cm3

Stresses at Lug: Tension stress z-axis, Stz = Fz /(WL tL) Bending stress z-axis, Sbz = HH(Fy/SLx+Fx/SLy) Shear stress y-axis, Ssy = Fy / (WL tL) Shear stress x-axis, Ssx = Fx / (WL tL) Total stress, ST = Sqrt( (Stz+Sbz)2+ Ssy2+ Ssx2) Check tension stress z-axis, Stz/Sta

= = = = = =

10.90 112.80 18.80 1.64 125.13 Safe

Check bending stress z-axis, Sbz/Sba

=

Check shear stress y-axis, Ssy/Ssa

=

Check shear stress x-axis, Ssx/Ssa

= =

0.34 in3 3.43 in3

MPa MPa MPa MPa MPa Ratio

= = = = = =

1580 16360 2727 239 18148 7.32%

Safe

Ratio

=

68.86%

Safe

Ratio

=

18.94%

=

Safe

Ratio

=

1.66%

Check total stress, ST/Sy

=

Safe

Ratio

=

50.41%

Unity Check, Stz/Sy + Sbz/Sy + Ssy/Sy + Ssx/Sy

=

Safe

Ratio

=

58.07%

Stresses near the Hole: Tension stress, Stz = K Fz / [(WL - DH) tL] Tension stress, Sty = K Fy / [(HH + R - DH) tL] Shear stress, Ssx = K Fx / [(WL - DH) tL] Total stress, ST = Sqrt( Stz2+ Sty2+ Ssx2) Bearing stress, Sbr = Fsl / [Dp (tL + 2tc)] Pull-out shear, Ssp = Fsl / [tL(R - ½DH) + 2tc(r - ½DH)] Check tension stress z-axis, Stz/Sta

= = = = = = =

35.53 58.75 5.36 68.87 128.69 56.85 Safe

MPa MPa MPa MPa MPa MPa Ratio

= = = = = = =

5153 8521 778 9989 18666 8245 23.86%

Check tension stress y-axis, Sty/Sta

=

Safe

Ratio

=

39.45%

Check shear stress x-axis, Ssx/Ssa

=

Safe

Ratio

=

5.40%

Check total stress, ST/Sy

=

Safe

Ratio

=

27.75%

Check bearing stress, Sbr/Sba

=

Safe

Ratio

=

57.61%

Check pull-out shear stress, Ssp/Ssa

=

Safe

Ratio

=

57.26%

Unity Check, Stz/Sy + Sty/Sy + Ssx/Sy

=

Safe

Ratio

=

40.15%

Hertz/Contact Stress Check at Pin Hole Pad Eye Design Load Pd Design Load per Unit Length P Modulus of Elasticity E Poisson Ratio v Diameter of Pin Hole DH Diameter of Pin Dp Hertz Stress at Pin Hole SH act=[P x E x ( DH - Dp)/(¶ x (1- v2) x DH-Dp)^0.5

= = = = = = =

10 Ton 0.6666667 Ton/ mm 200000 Mpa 0.3 35 mm 25 mm 22.45 Mpa

Allowable Hertz Stress SH Hertz Stress SH check

= =

620.53 Safe

Mpa Ratio

=

3.6%

Von Mises Stress Check as Lug Von Mises Stress Check as Lug (Actual) ((Stz+Sbz+Ssy)^2+3(Ssx^2+Ssy^2))^0.5 Von Mises Stress Check as Lug (Allowed) Von Mises Stress Check as Lug Check

= = =

146.20 186.16 Safe

Ratio

=

78.5%

Note: 1. Lateral force is calculated based on 5% sling force 2. Taken from Roy Craig Jr., "Mechanic of Materials", page : 619, Figure: 12.3

Page 4

psi psi psi psi psi

psi psi psi psi psi psi

WELD CALCULATION OF LIFT LUG 5 TON CAPACITY

General Data: Number of lug, NL

=

1.00

Safety Factor, SF Calculated Total Weight, WC

= =

2.00 5.00

Angle, α Vertical force z-axis, Fz Horizontal force y-axis, Fy

= =

60 deg 2.50 Ton

= =

1.05 rad 5512 lbs

= =

4.31 Ton 0.38 Ton

= =

9510 lbs 832 lbs

=

5.00 Ton

=

11023 lbs

= = = = =

12.99 0.00 0.39 0.00 9600

Lateral force x-axis, Fx Sling force, Fsl

FZ

Fsl

α

R FY

HT

Z

X

DH HH

Y

WL

Weld length (assume only top and bottom side welded -conservative method) Weld length around on lug, Aw = 2WL + 2tL = 330 mm Length of weld around on each cheek, A c = 2πr Fillet weld dimension on lug, w Fillet weld dimension on cheek, wc Allowable weld stress, S w Load on fillet weld per linear inch of weld: Tension stress of weld, S t = Fz / Aw

=

424 lbs/in

= =

74.29 N/mm 128.19 N/mm 11.22 N/mm

=

Shear stress of weld, Ss = Fy / Aw Lateral stress of weld, Sl = Fx / Aw

= =

732 lbs/in 64 lbs/in

Cheek plate stress of weld, Scp = Fsl tc / [Ac (tL + 2tc)]

=

0.00 N/mm

=

0 lbs/in

= =

10.51 MPa 18.13 MPa 1.59 MPa

= =

1524 psi 2630 psi

Load on weld: Tension stress of weld, ft = St / (0.707w) Shear stress of weld, fs = Ss / (0.707w) Lateral stress of weld, fl = Sl / (0.707w) Total stress of weld, fT = Sqrt( ft2 + fs2 + fl2 ) Each cheek pl. stress of weld, fc = Scp / (0.707wc) Check tension stress, ft/Sw Check shear stress, fs/Sw Check lateral stress, fl/Sw Check total stress, fT/Sw Unity Check, ft/Sw + fs/Sw +fl/Sw Check cheek plate stress

0 10 0 66.19

mm mm mm MPa

in in in in psi

= = = =

= =

21.02 MPa

= =

230 psi 3048 psi

=

0.00 MPa

=

0 psi

= = = = = =

OK OK OK OK OK OK

Ratio Ratio Ratio Ratio Ratio Ratio

= = = = = =

15.88% 27.39% 2.40% 31.75% 45.67% 0.00%

Book Reference : Eugene F.Megyesy, "Pressure Vessel Handbook-Eleventh Edition", page : 459.

Page 3