lifting lug

"LIFTING_LUG" --- LIFTING LUG ANALYSIS

Program Description:

"LIFTING_LUG" is a spreadsheet program written in MS-Excel for the purpose of analysis of lifting lugs, used in

rigging operations. The user can enter a desired factor of safety (most applications, F.S. = 5.0). The program will

determine the ultimate strength of the lifting lug based on several checks and will apply the desired factor of safety

to the strengths to attain allowable loads for the lifting lug.

This program is a workbook consisting of two (2) worksheets, described as follows:

Worksheet Name DescriptionDoc This documentation sheet

Lifting Lug Analysis of lifting lugs per 13th Ed. AISC Manual (ASD) and Reference #1a & b

Program Assumptions and Limitations:

1. The following references were used in the development of this program:

a.

b.

c. American Institute of Steel Construction (AISC) 13th Edition Allowable Stress Design (ASD) Manual (2005)

2. This program contains “comment boxes” which contain a wide variety of information including explanations of

input or output items, equations used, data tables, etc. (Note: presence of a “comment box” is denoted by a

“red triangle” in the upper right-hand corner of a cell. Merely move the mouse pointer to the desired cell to view

"Design and Construction of Lifting Beams" - David T. Ricker, originally published in American Institute ofSteel Construction (AISC) - Design Journal, 4th Quarter 1991."Design of Below-the-Hook Lifting Devices" - ASME BTH-1-2008, American Society of Mechanical Engineers.

"LIFTING_LUG.xls" ProgramVersion 1.4

04/19/202310:42:27

file:///tt/file_convert/55cf9771550346d03391a7ad/document.xlsxdocument.xlsx

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LIFTING LUG ANALYSISPer AISC 13th Edition ASD Manual, ASME BTH-1-2008, and

"Design and Construction of Lifting Beams" by David T. RickerProject Name: Client:Project No.: Prep. By: Date:

Input:

Design Parameters:Lug Yield Strength, Fy = 36 ksi

Lug Ult. Strength, Fu = 58 ksi

Edge Dist., a = 2.500 in.

Edge Dist., e = 1.000 in.

Lug Width, b = 6.000 in.

Rounded Edge? = NoWill Pin Rotate Under Load? = No

Hole Diameter, dh = 1.000 in.

Pin Diameter, dpin = 0.750 in.

Lug Thickness, t = 0.750 in.

AISC Factor of Safety, F.S.1 = 5.0AISC Factor of Safety, F.S.2 = 3.1 F.S.2 = max{3, Fy/(Fu/F.S.1)} ASME Notation

ASME Factor of Safety, F.S.3 = 3.0 Assuming Category B lifters

AISC Preferred Geometry AISC Alternate Geometry

Results:

Check Geometry:Check 1: O.K. dh - dpin > 0, Pin fits in hole, O.K.

Check 2: O.K. a >= max(0.5*dh,2*t), Plate Proportions are O.K.

Check 3: O.K. e >= 0.67*dh, Plate Proportions are O.K.

Check 4: N.G. e < 1.33*a, Use a,eff = min(a, 3*e/4, 4*t, dh*1.25) in design

a,eff = 0.75 in. 3*e/4 controls

a,max = 2.13 in. a,max = 2*t+.625

a,use = 0.75 in. Use a,eff in design

(continued)

C18

If dh-dpin <= 1/16" - Pin bearing needs to be checked. Otherwise: do not check bearing.

C19

It is suggested that the lug thickness not be less than 0.25*d, but never less than 0.5 in.

C20

Factor of Safety against Ultimate Strength. For most cases: F.S. = 5.0 is appropriate.

C21

Factor of safety against Yielding of steel. Please note that this should give a factor of safety against Ultimate Strength of 5.0 or a factor of safety against yielding of 3.0, whichever is larger.

"LIFTING_LUG.xls" ProgramVersion 1.4

04/19/202310:42:27

file:///tt/file_convert/55cf9771550346d03391a7ad/document.xlsxdocument.xlsx

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Tensile Strength of Lifting Lug (AISC Eqn. D5-1):P1 = 13.05 kips P1 = (2*a,use*t*Fu) / F.S.1

Bearing Capacity of Lifting Lug (AISC Eqn. J7-1):P2 = N/A kips P2 = (1.8*Fy*t*dpin) / F.S.2

Per Ricker, only check bearing capacity if pin is "snug" in hole

Tearing Tension Capacity of Lifting Lug (Ricker pg 152):P3 = 14.53 kips P3 = {(1.67*Fy*t*e^2)/dh} / F.S.2

Per Ricker pg. 152, Fb is used instead of Fy, but Fb = Fy/F.S.2

Shear Capacity (Shear Rupture) of Lifting Lug (AISC Eqn D5-2):P4 = 10.44 kips P4 = (0.6*Fu*2*t*e) / F.S.1

Per AISC Eqn. D5-2, Asf = 2*t*(e+dh/2), cons. to assume dh/2=0)

Gross Section Yielding of Lifting Lug (AISC Eqn D2-1):P5 = 52.20 kips P5 = (Fy*t*b) / F.S.2

Tensile Strength of Lifting Lug (ASME Eqn. 3-45):Cr = 0.818 Cr = 1 - 0.275*sqrt{1 - (dpin^2 / dh^2)}

a,eff = 1.53 in. a, eff = min(a, 4*t, 0.6*a*(Fu/Fy)*sqrt(dh / a)

P6 = 30.22 kips P6 = (Cr*Fu*2*t*a,eff) / (1.2*F.S.3)

Single Plane Fracture Strength of Lifting Lug (ASME Eqn. 3-49):R = 1.500 in. R = e+(dh/2)

P7 = 16.67 kips P7 = [(Cr*Fu)/(1.2*F.S.3)] *

[1.13*(R-.5*dh)+(0.92*a,eff)/(1+a,eff/dh)] * t

Double Plane Fracture Strength of Lifting Lug (ASME Eqn. 3-50):41.25 deg.

Z' = 0.000 in.

Av = 1.640 in.^2

P8 = 18.49 kips P8 = (0.7*Fu*Av) / (1.2*F.S.3)

Bearing Capacity of Lifting Lug (ASME Eqn. 3-53):P9 = 8.44 kips P9 = (1.25*Fy*dpin*t) / F.S.3 <============= Controls

Summary:Pallow = 8.44 kips Pallow = min(P1, P2, P3, P4, P5, P6, P7, P8, P9)

Required Weld Strength for Vertical Load:Pdesign = 12.66 kips Assuming fillet weld and F.S. = 5.0 against Fexx. Use Pdesign

to design welds using 0.3*Fexx*0.707*weld size. Could also use

Pallow, but need to use 0.2*Fexx*0.707*weld size for F.S. = 5.0.

Comments:

f = f = 55*(dpin / dh)

Z' = R - sqrt{R^2 - [(dpin/2)*sin(f)]^2}, only applicable for rounded edges

Av = 2*{e+0.8*dpin*[1-cos(f)]-Z'}*t

C56

If pin is not "snug" in hole, then bearing does not need to be checked

C59

If pin is not "loose" in hole, tearing tension does not need to be checked.

lifting lug

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