stiffner13-steel beam web stiffeener analysis

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"STIFFNER13" --- STEEL BEAM WEB STIFFENER ANALYSIS

Program Description:

"STIFFNER" is a spreadsheet program written in MS-Excel for the purpose of analysis of steel beams subject

to concentrated loads. Specifically, web yielding, web crippling, and web buckling criteria are checked to

determine if web stiffeners are required to resist the concentrated load. If stiffeners are required, the stiffener

size and weld requirements are determined.

This program is a workbook consisting of three (3) worksheets, described as follows:

Worksheet Name Description

Doc This documentation sheet

Beam Stiffeners Steel beam web stiffener analysis for concentrated load

Beam Stiffeners (Table) Steel beam web stiffener analysis for concentrated loads (table

Program Assumptions and Limitations:

1. This program follows the procedures and guidelines of the AISC 13th Edition Allowable Stress (ASD) Manualfor wide flange beams subjected to concentrated compressive loads per Chapter J10, pages 16.1-115 to 16.1-121.

2. This program uses the database of member dimensions and section properties from the "AISC Shapes

Database", Version 13.0 (2005) as well as the AISC 13th Edition (ASD) Manual (2005).

3. For the purpose of determining the total composite section to be considered for resisting the compressive

load, the program assumes a spacing of 3" center-to-center between the stiffener pairs. Thus the total

effective strips of web to be included in the composite section along with the stiffeners are as follows:

For interior condition (P or R > d/2):

1-pair: 25*tw

2-pairs: 25*tw+3"

3-pairs: 25*tw+6"

For end condition (P or R


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"STIFFNER13.xls" Program

Version 1.3

STEEL BEAM WEB STIFFENER ANALYSISFlange Local Bending, Web Yielding, Crippling, Buckling, and Stiffener Criteria

for Concentrated Load or Reaction Per AISC 13th Edition Manual (ASD)

Project Name: Client:

Project No.: Prep. By: Date:

Input Data:

Beam Size: N = 12

Select: W18x35

x = 10

Beam Load or End Reaction: P = 30

Load or Reaction? (P/R) P

P or R = 30.00 kips k = 0,827

Design Parameters:

Beam Yield, Fy = 33 ksi Stiffener

Bearing Length, N = 12.000 in. (NS & FS) N+5*k

Bearing Width, B = 6.000 in. N+2.5*kUnbraced Length, Lb = 20.000 ft. Stiffener (NS & FS)

Distance to P or R, x = 10.000 ft.

Actual Moment, Ma = 2.0 ft.-kips

Yield Moment, My = 158.4 ft.-kips k = 0,827 W18x35

Loaded Flg. Restrained? No x

Stiffener Thickness, ts = 3/8 R

Stiffener Yield, Fys = 36 ksi Nomenclature

Number of Stiff. Pairs = 1-Pair N Notes: 1. When stiffeners are required, program

assumes full height stiffeners.

Beam Properties: 2. Only 1-pair of stiffeners depicted at either

d = 17.700 in. reaction or load (if required) but may be

tw = 0.300 in. 2-pairs or 3-pairs spaced 3" o.c.

bf = 6.000 in.

tf = 0.425 in.

k = 0.827 in.

Sx = 57.60 in.^3

Results:

Gross Shear Capacity of Beam Web:

Rv = N.A. kips Rvg = (1/1.5)*0.60*Fyb*Cv*Avg (Not ap

Local Flange Bending:

Rfb = N.A. kips Rfb = (1/1.67)*6.25*tf^2*Fy

(Not applica

Local Web Yielding: (Criteria is for P away from beam end per AISC Eqn. J10-2)

Rwy = 106.49 kips Rwy = (1/1.5)*Fy*tw*(N+5*k) R

Web Crippling: (Criteria is for P away from beam end per AISC Eqn. J10-4)

Rwc = 92.48 kips Rwc = (1/2)*0.80*tw 2*[1+3(N/d)*(tw/tf)^1.5]*sqrt(E*Fy*tf/tw)

R

in.

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Version 1.3

Sidesway Web Buckling: (Criteria is for beam with unrestrained top flange per AISC Eqn. J10

h = 16.046 in. h = d-2*k

Cr = 960,000 ksi Cr = 960,000 ksi when 1.5*Ma < My

(dc/tw)/(Lb/bf) = 1.337 Critical ratio for sidesway web buckling =

Check Stiffener Slenderness and Compressive Stress:

h/t = 0.76 kc = max{ 0.35, min[ 0.76, 4/sqrt(h/t) ] }, h/t = 25 for int. & 12 for ext.

b/t = 6.67 b/t = bs/ts

b/t(max) = 15.84 b/t(max) = 0.64*SQRT(kc*E/Fys)

K = 0.75 (assumed effective length factor per AISC Code, page 16.1-121)

L = 16.05 in. L = h = d-2*k

I = 4.67 in.^4 I = 2*(ts*bs^3/12+(ts*bs)*(bs/2+tw/2)^2)+(25*tw)*tw^3/12

A = 4.13 in.^2 A = 2*(ts*bs)+(25*tw)*tw

r = 1.064 in. r = SQRT(I/A)

fa = 7.27 ksi fa =P/A

KL/r = 11.31 (effective slenderness ratio for compression)

Fe = 2236.6 Fe = p^2*29000/ (KL/r)^2

Fa = 21.56 ksi If KL/r


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Version 1.3

d=17,7

licable for P)

ble for ts > 0)

y >= P, O.K.

c >= P, O.K.

(continued)

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Version 1.3

7)

wb < P, Fail

.)

ts(min), O.K.

>= fa, O.K.

ld max., O.K.

ld max., O.K.

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STEEL BEAM WEB STIFFENER ANALYSISFlange Local Bending, Web Yielding, Crippling, Buckling, and Stiffener Criteria for Concentrated Load or Reaction

Per AISC 13th Edition Manual (ASD)

Project Name: Client:

Project No.: Prep. By: Date:

Input Data:

N

Beam Yield Stress, Fyb = 50 ksi

Stiffener Yield, Fys = 36 ksi x

P

k

Stiffener

(NS & FS) N+5*k

N+2.5*k d

Stiffener (NS & FS)

k Beam

x

R Nomenclature

N

Beam, Load Load or Unbraced Distance Is Loaded Stiffener Bearing Bearing Actual Yield No. of Beam Web Capac

Location, Beam or Reaction Length to P or R Flange Thk. Length, Width, Moment Moment Stiffener Web Shear Flg Bending Web Y

or Node Size Reaction? P or R Lb x Restrained? ts N B Ma My Pairs Rv Rfb Rw

I.D. (P or R) (kips) (ft.) (ft.) (Yes / No) (in.) (in.) (in.) (ft.-kips) (ft.-kips) (1, 2, or 3) (kips) (kips) (kip1-200 W18x35 R 30.00 20.000 0.500 No 3/8 12.000 6.000 240.00 240.00 1 106.20 N.A. 1401-200 W18x35 P 30.00 20.000 10.000 No 3/8 12.000 0.500 2.00 240.00 1 N.A. N.A. 161

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Beam, Load Load or Unbraced Distance Is Loaded Stiffener Bearing Bearing Actual Yield No. of Beam W

Location, Beam or Reaction Length to P or R Flange Thk. Length, Width, Moment Moment Stiffener Web Shear Flg Bending

or Node Size Reaction? P or R Lb x Restrained? ts N B Ma My Pairs Rv Rfb

I.D. (P or R) (kips) (ft.) (ft.) (Yes / No) (in.) (in.) (in.) (ft.-kips) (ft.-kips) (1, 2, or 3) (kips) (kips)

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Beam, Load Load or Unbraced Distance Is Loaded Stiffener Bearing Bearing Actual Yield No. of Beam W

Location, Beam or Reaction Length to P or R Flange Thk. Length, Width, Moment Moment Stiffener Web Shear Flg Bending

or Node Size Reaction? P or R Lb x Restrained? ts N B Ma My Pairs Rv Rfb

I.D. (P or R) (kips) (ft.) (ft.) (Yes / No) (in.) (in.) (in.) (ft.-kips) (ft.-kips) (1, 2, or 3) (kips) (kips)

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stiffner13-steel beam web stiffeener analysis

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