Cold-Formed Steel BeamDesign

Version 2.1

Load Carrying Capacity – Beam Curves and Tables

Owner’s Manual

http://www.devstruc.com

Index

About BeamDesign ........................................................................................... 3

Installing BeamDesign ...................................................................................... 5

Main Window ..................................................................................................... 7

Materials Window .............................................................................................. 8

Section Edit Window ......................................................................................... 9

BeamDesign Window ........................................................................................ 14

Options Window ................................................................................................ 23

Technical Considerations .................................................................................. 24

Appendix ........................................................................................................... 27

About Cold-Formed Steel BeamDesign Cold-Formed Steel BeamDesign is a friendly and powerful software for the design of

flexural members of Cold-Formed Steel, following AISI 2001 and 1996/99 Specifications.

The principal aim is to analyze a simple or continuous beam (2 to 4 equal spans) and to

determine the permitted load (Uniform or Concentrated Load allowed) carrying capacity,

while varying the span length (L). Also you can compare one section and two different

steels, or two sections with the same steel.

In this new version user is able to know the load-carrying capacity value for a specific span

length, being displayed these values in the “References” window.

ASD or LRFD approaches, determine Wall (W-allowable) or Wu (W-ultimate), showed by

Envelope Curves and Tables, or optionally their respectively seven Wi simple components

and Weq (Equivalent to Construction Load).

As efficient coefficients (W/Weight), for ratio between Load-Carrying Capacity and Full

Sectional Weight are giving by Envelope Tables, users can optimize designs, by choosing

their proper Section, Steel and restrictions.

Fourteen different sections are allowed (CS, CU, ZS, ZU, LS, LU, HU, RB, SB, IC, CC, IU,

TS, and TU), with selected Steels (16 ASTM Referenced Standards Steels are provided as

a guide). BeamDesign comes with the section dimensions from the AISI Manual for each

shape, and also user can create new section dimensions. In this new version we add tables

for the following manufacturers: Dietrich, Marino-Ware and SSMA.

Another feature from BeamDesign is you can calculate Geometric and Effective Properties

for provided sections and also for sections created by user.

All Curves and Tables are available for printing with the complete information on headers.

Besides engineers and other professionals, teachers and students also may be able to

profit the versatility of our sofware, changing optional parameters to obtain different curves

and tables or studying the Nominal Flexural Strength for Lateral Buckling Moment (Mnb)

versus L (Span Length) for different Shapes and Steels, or comparing “CS” and “ZS” curves

with AISI Design Manual Charts.

Highlighted Options:

• Supported Specifications

• 2001 AISI - US (ASD and LRFD)

• 2001 AISI - Canada (LSD)

• 1996/1999 AISI (ASD and LRFD)

• Fya: increasing Fy (Virgin Yield Strength) value, due to cold work of forming.

• Sections with Web Holes (only CS, CU, ZS, ZU, IC, IU and CC Sections).

• Gravity or Uplift loads.

• Uniform and Concentrated Load (L/2).

• Fastened Flanges: Top, Bottom, both Top and Bottom or Unfastened Flanges.

• Fastened to Support Flanges.

• Bracings: Against lateral displacement and/or twisting.

• One Flange Fastened to a Standing Seam Roof System.

• Bearing Supports: Interior Laps; variable Widths and Web Stiffeners for

intermediate, end and/or interior Supports.

• Variable Maximum Deflection Limit.

• Beam Spacing.

• Cb: Bending Coefficient for increasing Critical Buckling Strength.

• Reference Span Length and Load Required can be modified by user.

• Wi values are displayed for all curves, for required span length.

• Units available in American Units and International Units.

• Units in feet and inches for Span Length.

• Units for Uniform and Concentrated Load.

• Calculate Geometric and Effective Section Properties.

• Dimensional Limits for each Section.

• Messages are given for exceeded limits such as b/t, d/t and h/t.

• Curve Notes and Error Messages advise for correct AISI employment.

• Databases for the following manufacturers: Dietrich, Marino-Ware and SSMA.

Installing BeamDesign

System Requirements

Hardware requirements: 20 MB of available disk space. 56 MB of RAM.

Operating System: Microsoft Windows 98, NT, 2000, Me, XP, Vista and 7 (32 & 64 bits).

What's Inside?

After the download is complete, you will see a file named BeamDesign.exe in your

download location. Then just double click on the file and follow the steps in the installation

wizard.

The folder contains the application, the “Library” folder, a readme file and the BeamDesign

Manual. Inside the “Library” folder you will find Sections and Table files.

When user starts BeamDesign he will complete the register dialog box for personalizing his

copy.

If your serial number is correct a copyright window will appear. After this the welcome

windows is displayed until you click mouse. It indicates the User Name, Company and

Version Type (Professional or Academic).

Main Window After the copyright window has been displayed, the main window will appear on screen.

Two groups, “Sections” and “Materials” and their respective tables are loaded.

“AISI-Sections” and “ASTM-Steels” are implemented with the program and loaded for the

first time, corresponding to tables founded in “AISI Cold-Formed Steel Manual Design -

1996 Edition” and “AISI Cold-Formed Steel Manual Design - 2008 Edition”.

Many tables of each group can be stored in “Library” folder. Last tables used, are loaded

when the user starts up. The “Library” folder should not be erased or changed its name.

Also new Sections and Materials files created should be saved within the “Library” folder.

The main window contains two different groups (Sections and Materials) and the Beam

Design button. Inside the groups you will find another two buttons. The “Change Table”

button lets you change the table loaded in default, and select other table from the “Library”

folder. The “Edit Table” button call the “Section Edit” and the “Materials Edit” windows.

The allowable units for tables are:

a) Sections Tables: “in” inches or “mm” millimeters.

b) Steels Tables: “ksi” or “MPa”.

Materials Window First Column (x) set active or inactive the Standard Specifications you want to use with the

program.

The “Change” button modifies only the editable fields: Modulus E and G. The allowable units are:

a) Steels Properties in International Units (SI) - MPa. b) Steels Properties in American Units (US) - ksi.

Section Edit Window This window shows selected sections and materials, geometric and effective properties,

Increased Strength (Fya) and Weight (wt). Also shows options for units (SI or US), holes

and section drawing.

• Selecting Section

The sections are arranged in the library in groups. Each of the groups consists of a range of sections of a similar type. Menu shows the allowable Sections: CS, CU, ZS, ZU, LS, LU, HU, BR, BS, IC, IU, TS, TU and CC.

Simple Sections CS (Stiffened Channel), CU (Unstiffened Channel), ZS (Stiffened Zeta), ZU (Unstiffened Zeta), HU (Hat), LS (Stiffened Angle), LU (Unstiffened Angle), BR (Rectangular Box), BS (Square Box).

Composed Sections IC (two “CS” Back to Back), IU (two “CU” Back to Back), TS (two “LS” Back to Back), TU (two “LU” Back to Back), CC (two “CS” Face to Face). “LS”, “LU” and “TU” are considered only for Section Properties Calculations.

• Selecting Sections

Choose the Section by its ID (Identification). Dimensions and properties are displayed.

• Selecting Referenced Steels

Select the steel, and the following properties changes: Effective Modulus (Se), Effective Inertia (Ie), Full Section Tensile Yield Strength Increased, top and bottom, (Fya t) and (Fya b), and if the section is compact.

• Drawing Section (Help)

Shows Section Parameters when help is checked. Shows a Scale Drawing when help is not checked. (SC) Shear Center – (CG) Centoid.

• Hole Options

If Holes is checked, Section Properties are calculated considering Holes.

• Units

Shows Properties in International Units (SI). Shows Properties in American Units (US).

• Additional information

Units of Table for Sections Units of Table for Steels Virgin Yield Strength (Fy) Virgin Ultimate Tensile Strength (Fu) Fu / Fy ratio

• Editable Fields

1) Section Name (ID) Dimensions

2) A’= “Depth of Section”

3) B’= “Flange Width”

4) C’= “Overall Depth of Lip”

5) t’= “Section Thickness>= 0.89mm (35mils)” (Also available Gage units)

6) Ri= “Inside Bend Radius”

7) ga= “Angle between a Flange and its edge stiffener”

8) do / dh: Diameter (do) or Depth (dh) of Web Hole. do/h <0.7. (h= Depth of Flat Portion of the Web). Circular Hole: (C) 9/16in (14mm) < do <= 6in (152mm). Square Hole: (S) dh <= 4.25in (108mm), Diagonal <=6in (dimensions fit within an allowable circular) - corner radius>= 2t. Rectangular Hole: (R) Diagonal <= 6in (152mm) (dimensions fit within an allowable circular) – corner radius>= 2t”

• Dimensional Limits

Flange (b/t)= “Flat-width-to-Thickness Ratios” Lip (d/t)= “Lip-width-to-Thickness Ratios” Web (h/t)= “Flat-depth-to-Thickness Ratios”

• Section Properties Calculated

A= “Full Sectional Area” Ix= “Full Mom. of Inertia X” Iy= “Full Mom. of Inertia Y” Ixy= “Product of Inertia” Xr= “Distance X to C.G. (Centroid)” Yr= “Distance Y to C.G. (Centroid)” Xo= “Distance (C.G.-S.C.) Shear Center to Centroid” Jt= “St. Venant Torsion Constant” Je= “Parameter for Elastic Critical Moment” Cw= “Warping Constant” Wy= “Full Section Modulus Y - Minimum” Wx= “Full Section Modulus X - Minimum”

Sx top= “Effective Section Modulus - Compression Top” Sx bot= “Effective Section Modulus - Compression Bottom” Iex= “Effective Moment of Inertia for Deflection” Fya top= “Full Section Tensile Yield Strength (Increased) - Compression Top” Fya bot= “Full Section Tensile Yield Strength (Increased) - Compression Bottom” Compact=“Compact Compression Flange - Ro=1” wt=“Full Sectional Weight”

• Error Messages

Section DOESN'T VERIFY Geometric Conditions:

“Ratio (Flange Flat Width/Thickness) w/t> 60” “Ratio (Web Depth/Thickness) h/t> 200” “Thickness t< 35 mils (0.89 mm)” “Ratio w/t> 500” “Ratio Ri/t> 6” “Ratio h/t> 200” “Ratio c/t> 14” “Ratio do/h> 0.7” “Holes Diagonal<= 6 in (152mm)” “Holes Diameter<= 6 in (152mm)” “Holes Diameter > 9/16 in (14mm)”

“Save As” Dialog Box

If user has inserted, deleted or changed any input dimension, when “Done”, program shows

a “Save As” dialog in order to save new Section Table.

“Section Edit” Screenshots

1) Section 9CS3x075

2) Section 8ZS2.5x075

3) Section 3HU4.5x135

4) Section I9CS3x075

BeamDesign Window BeamDesign analyzes a simple or continuous beam and determines the permitted Uniform

Load (W) or Concentrated Load (P) Carrying Capacity, while varying the span length (L). By

default W units are (kips/ft) or (kN/m).

Calculated values (W, L) or (P, L) are represented by Curves and Tables.

Select Sections

Menu allows selecting ten (10) possible sections for curves and tables: CS, CU, ZS, ZU, HU, BR, BS, IC, IU, TS, TU, CC.

Analysis Method (AISI 2001 and AISI 1996/99)

• ADS Approach: Allowable Design Strength for Allowable Loads (Wall).

• LRFD Approach: Load and Resistance Factor Design for Ultimate Loads (Wu).

• LSD Approach: Limit States Design for Ultimate Loads (Wu).

For LRFD and LSD see “Options” windows with suggested Load Factors. By default,

for Construction Load (g= 1.4) and for Deflection (g= 1.6).

Units

• Uniform Load

t/m, kg/m, KN/m, N/m, t/cm, kg/cm, KN/cm, N/cm, kip/in, kip/ft, lbf/ft (plf), lbf/in

• Concentrated Load

tn, kg, kN, N, kip, lbf

Holes

Check “Holes” for Central Web Holes allowed for seven sections: C, U, Z, ZU, IC, IU and CC. “Holes” button is available if the hole diameter was previously changed in the “Section Edit” window. Clear Distances between Holes >=18 in. (457mm) Clear Distances between First Hole to Edge Support>= A' (A'=Depth of the Section). See Editable Fields (8) at “Section Edit” for more information.

Envelope and Simple Curves

Check “Envelope” for Uniform Load Beam Capacity (Wall. or Wu.) versus Span Length (L). Otherwise program draws Simple Load Curves W (1 to 7) and Curve (8*) Weq. Curve (9*) Mn will be drawn only if was checked in Options

Load Capacity Due to:

“Bending Only” “Bending for lateral Buckling” “Shear Only for End Reaction” “Shear” or “Shear + Bending for Interior Reaction” “Web Crippling (W.C.) for End Reaction” “W.C.” or “W.C. + Bending for Int. Reaction” “Maximum Deflection” 8*) “Equivalent to Construction Load” 9*) “Curve Mnb= Nominal Flexural Moment”

Compare Sections

If you select 1 Section, Curves 1 and 2 are drawing for Steels 1 and 2. If you select 2 Sections, Curves 1 and 2 are drawing with Steel 1

Checking “AS”, program show all dimensions for all sections in the listbox. So you can compare a C-Section dimension with a U-Section dimension. Otherwise program show only dimensions for the selected section.

Use Fya

Check Fya due to cold work of forming, for increasing Fy value. Fya (Average Yield point of Steel in the full section).

Steel Menu

Select Steel 1 for Curve 1. Select Steel 2 for Curve 2. Disable Steel 2 (Steel 2 for Curve 2 = Steel 1 for Curve 1).

Selecting Span number

From 1 to 4 Spans of a Continuous Beam.

Fixing Cb Value

Fix Cb Value= 1 Otherwise Cb>= 1 is calculated. Cb is a Bending Coefficient dependent on Flexural Moment Gradient that increases Critical Buckling Strength.

Beam Deflection

If Deflection is Considered, input Maximum Deflection Limit= ratio Length /Maximum Deflection. Default value = 240.

Beam Spacing

If Beam Spacing<> 1m (ft), Load Carrying Capacity Units (Wall or Wu) are kN/m2 or kips/ft2.

Default value= 1m (ft), Load Carrying Capacity Units (Wall or Wu) are kN/m or kips/ft.

Specific Span Length for a Beam

In this new version user is able to know the load-carrying capacity value for a

specific Span Length.

In the “References” box are displayed the values of the required load and the Wi

values of the load-carrying capacity corresponding to desired span length.

Inside the “Curves” window the Wr is displayed through a triangle. For making the

comparison between Wr and Wi, the triangle icon has three states:

Green: the required load by the user is lower than load-carrying capacity for the two

steels (Section verifies - OK).

Yellow: the required load by the user is lower than load-carrying capacity for one

steel. (Section doesn’t verify for steel 1 – Section verifies for steel 2)

Red: the required load by the user is higher than load-carrying capacity for the two

steels. (Section doesn´t verify – NOT OK).

These values are also displayed in the “References” window (Sr and Wr).

• Reference Span Length

Write a desired Span Length.

• Required Load

Write a desired Load.

Span Length Range

From: Initial length value for drawing curves and calculating tables. To: End length value for drawing curves and calculating tables.

Show range in inches and feet. Load Cases

Uniform Load Concentrated Load (L/2) Gravity (Beam Weight Included) Suction (UpLift) - (Beam Weight Included)

Fastened Flange

Free Flange Top Fastened Flange (See different advices with Curves) Bottom Fastened Flange (See different advices with Curves) Both Fastened Flanges

Stiffeners

Check “Es”, “In” or/and “Is” for Web Stiffeners, against Web Crippling, for increasing Load Carrying Capacity. Es: Web Stiffener at End Support. In: Intermediate Web Stiffeners. Is: Web Stiffener at Interior Support. Notes: advice the Span Length Limit for economical Stiffener use.

Bracings

Check “y” for Lateral Bracings (Against Lateral Deflection) – “y” Direction is perpendicular to Load Direction. Check “t” for Rotational Bracings (Against Twisting)

For “Fix Point” button disabled: Case 1 - Number: Number of Bracings for each Span (Recommended <= 3) For “Fix Point” button enabled: Case 2: Instead of Number, Spacing Length will be specified for several Bracings. (Use full for One Flange Fastened to a Standing Seam Roof System, see AISI Specification Section C3.1.4).

Using Laps

Check Lap on Interior Supports for increasing Load Carrying Capacity. External Lap Length (ELL) = % of Span Length. Internal Lap Length = 1.5xELL - (for 4 spans, Central Lap Length = ELL). Check “Fastened to Support” (Only for AISI 2001)

Support Width

Ne: End Support Width: minimum 1.5 in (38 mm) - (Increase width Against Web Crippling). Ni: Interior Support Width: minimum 3 in (76 mm) - (Increase width Against Web Crippling).

Buttons

“Graph”

Updates Curves with selected options

“Table / Curves”

Switches between Table Forms or Curve Drawings

“E” (Zoom for W curves)

Switches among: (E) Envelope, maximize scale to show Envelope curves. (R) Reduced, maximize scale to show all simples curves. (F) Fit, maximize scale to show simples curves selected.

Menu

“Print”

The program shows Page Setup Dialog and selects the Paper size and orientation and margins. Table Forms: select Vertical orientation Curve Drawings: select Landscape orientation

“Options”

Open the “Options” window.

“Sections Table” and “Materials Table”

Open the Sections and Materials window (You can not make changes in this tables, it is only for consult).

“User’s Guide”

Open the User´s Guide in Adobe Acrobat Reader (Keyboard Shortcut is F1).

“Check for Updates”

Check if there are new versions of BeamDesign available for download. Contextual Menu

• Show/Hide:

References

Beam Icon

Section Icon

Change Curves Line Thickness

References Lines – Wr

Change Color Curves

• Call windows:

Options

Print

Advises with Curves

Users must fulfill the Following Conditions for:

“Laps at Support Not Convenient (For Economy)”.

“Tension Fastened Flange: See Appendix A (9 to 15)”.

“End Support Member Thickness>= 3/16 (4.76mm)”.

“Interior Support for two Nested Z: See Appendix B”.

“Web Stiffener at End Support: B 6.1 (all)”.

“Web Stiffener at Interior Support: B 6.1 (all)”.

Headers for Curves and Tables

First Line: Type of Curve, Specifications, Approach Method, Load-Length and Units,

Section name and/or Steel (Fy/Fya), for Simple or Envelope Curve, respectively.

Second Line: Span Number, Loads (Presion or Uplift), Laps Length (%L), Beam

Spacing, Flanges (Free or Fastened), Bracings.

Third Line: Web Stiffeners at Supports (Considered or Not), Hole (Considered or

Not).

Fourth Line: Maximum Deflection Limit (or Not Considered), Cb (Bending

Coefficient).

Complementary Drawings for Curves

Icons for Sections in scale: Drawing Sections, Bracings (“y” and “t”) and Fastened

Flanges (Top and/or Bottom).

Beam Diagram View: Span Number, Gravity or Uplift Loads, Laps (if any), Bracings

(if any).

For simple curves, dotted lines indicate that they are not included in envelope

curves.

The possible cases are:

a) W5 - With Web Stiffener at end Support.

b) W6 - With Web Stiffener at interior Support.

c) W7 – Maximum Deflection not considered.

d) W8 – Equivalent to Construction Load (always in dotted line).

Display Tables

Envelope

W-env.1 and W-env.2 show values from Curve 1 and Curve 2 respectively.

Simple governing causes (W1 to W7) witch determined the minor Load Carrying

Capacity for each case are given, and efficiencies W-env.1/Wt and W-env.2/Wt,

and the relative efficiency W-env.2/W-env.1 are so written.

If W-env.1 and W-env.2 values are minor to W8 (Equivalent to Construction Load),

text changes to “Italic Style”.

Simple Curves

Simple Curves and (W8) are also given in tables.

Governing values are all painted to highlight them (green). If some of these values

are minor to W8, color changes (red).

Curves and Tables Screenshots Example I: Four Span Continuos ZS – Purlin Design – ASD Method 2001

Envelope Curves for “ZS” Section with Fy1=55ksi, Fy2=33ksi

Envelope Tables for “ZS”

Simples Curves for “ZS” Section

Simple Tables for “ZS” Section

Example II: C-Section without Lips Braced At Mid-span, and Web Stiffeners at Supports

Envelope Curves for “5.5CU1.25x057” Section with Fy1=33ksi, Fy2=50ksi

Envelope Tables for “CU” Section

Simples Curves for “CU” Section

Simple Tables for “CU” Section

Options Window

Simples Curves

Simple Curves are grouped as: a) “Load Carrying Capacity” (W1 to W7) and “Equivalent Construction Load”

(W8) Curves. b) “Mnb-Nominal Flexural Moment”.

Check let active a) or b) group and to select each Wi. Unselected curves are not showed in graphics (in zoom mode “E”, “F”; in mode “R” simple curves are all showed).

Show

Show or Hide: References, Beam and Section Icons, Gross line for drawings and

References Lines for Wr.

Load Factors

Change default value for Deflection and Construction Load. • Span Length Range Units

Check for show units in feet.

Technical Considerations

Cold-Formed Steel BeamDesign for flexural members of CFS, was entirely conceived

following AISI 2001 and 1996/99 Specifications.

Certainly, some practical restrictions were introduced:

1. Beams are supposed simple or continuous elements over fixed supports. They will be

firmly connected to both the top and the bottom flanges, to prevent from twisting and lateral bending at the ends of each span.

2. “Fastened Flange”, means that these compression flange, (bottom or top), is through attached to a rigid plane diaphragm (deck or sheathing) over (or under) the flange, (see AISI 96 Section D, for more information), to effectively restrain the flange against twisting and lateral bending all along the beam.

3. Beams (C or Z shapes) having the tension flange attached as Section C3.1.3 states (Fourteen conditions), with the compression flange laterally unbraced, are partially restrained against lateral bending. Factors R<1 are specified to reduce Nominal Section Strength for Bending Only. The program checks first nine conditions. Users must fulfill last five conditions.

4. For this Version, the constant Moment of Inertia Ix, based on the full span section was adopted for a linear analysis of the Continuous beam (2 to 4 spans), instead of the variable effective Moment of Inertia, due to the different effective areas of the compression flange and web, along the beam. For C and Z shapes using short laps at interior supports, exact flexural moments are lightly smaller on spans but lightly bigger on supports. As the moment region between the end of the lap and the inflection point, for lateral buckling is treated as a cantilever with an unbraced free end, conservatively, program increases that unbraced length for calculations, and errors are minimized. (See 7).

5. For Deflection determinations, as eventual Laps are short, (See: Using Laps…) and 1999 AISI Supplement, neglects allowed Central Web Holes, a constant Effective Moment of Inertia Iex is used for these Version following AISI Design Manual criteria. (Iex is calculated based on the effective span section, at a service load of 60% of Mn, and assuming approximately a maximum compressive stress of 60% of Fya).

6. Program allows optionally, for calculations, to use increased Fya (Average Yield Point of the Full-Section) in lieu of Fy (Virgin Yield Strength), by effect of cold work of forming, only for “Compact” compression flange, (where the reduction factor Ro, determined in accordance with Section B2 equals unity), with Fu/Fy>= 1.2 and Ri/t’<= 7, (section A7.2). For non-symmetric sections, conservatively program adopts for the full beam, the smallest value between Fya top and Fya bot (calculated for top or bottom compression flange respectively).

7. Cb, Bending Coefficient for Increasing Critical Buckling Strength, is calculated in accordance with Equation C3.1.2-11 (AISI 96), due to variable shapes of flexural moment diagrams within the unbraced segments for compression flanges. At regions with unbraced length between the inflection point and the interior support (or conservatively the middle of the lap if any), sections are treated as unbraced cantilevers, with a free end, and Cb=1. Users can fix Cb=1 and assumed it for the full beam, otherwise program calculates Cb>=1, for all the different segments and chooses for all the beam, the worst combination of Cb with it respective bending length. Maximum Cb=2.3 (adopted).

8. Load Carrying Capacity Wall or Wu are calculated by ASD or LRFD Method. Wall. gives the envelope Allowable Uniform Load, for six nominal design strengths, (additionally a seventh limitation, for beam deflection is considered), divided by their corresponding specified safety factors W.

9. Wu gives the envelope Ultimate Design Uniform Load, for six nominal resistances, (additionally an equivalent one for beam deflection is considered), multiplied by their corresponding specified resistance factors Ø. Wu must be confronted with the different load combinations of required uniform strength for factored loads (or required resistance). AISI96 recommendations, (Section A4), are based on ANSI/ ASCE 7 Specifications.

10. Loads for Nominal Strengths or Resistances: Simple Curves and Tables.

W1 - Bending Only

W1- L Curve (or table) gives Load Carrying Capacity, for the Nominal Strength for Bending, with lateral buckling restricted. Procedure I (Sec.3.1.1.), was chosen for Mn=Se.Fy, with Se, (effective section modulus) calculated with the extreme fiber at Fy. W2 - Bending for lateral Buckling

W2- L Curve (or Table) gives Load Carrying Capacity for the Nominal Strength for Bending (Mnb), with lateral buckling. Mnb=Sc.Fc, with Sc, (Effective Section Modulus) calculated with the extreme compression fiber at Fc (elastic or inelastic Critical Stress)=Mc/Sf, with Sf (Full Section Modulus), (Sfx for all, except H sections with rotated axis), and Mc, Critical Moment for Lateral-torsional buckling. a) Critical Stress Fc is calculated for open cross sections members, C-Channels, I-Beams and Z-Beams,(singly, doubly and point symmetric sections), with twisting and lateral displacement as an unity, for lateral-torsional buckling, following Sec.C3.1.2.1 of the 1999 AISI Supplement. (Procedure a).

b) Critical elastic Stress Fe in lieu of Fc, is calculated for closed box-type member sections BR and BS (Square and rectangular boxes), following Sec.C3.1.2.2 of the 1999 AISI Supplement.

c) Design Stress Fb2 in lieu of Fc, is calculated for member sections H (Hat or inverted hat), where compression flanges tend to buckle separately accompanied by out-of-plane bending of the web, following the simplified analysis, in Sec.2 of Part II, of the 1996 AISI Design Manual.

For 1999 AISI Supplement when the depth of holes do/h>=0.38, effective width shall be determined by section B.3.1(a). W3 - Shear Only for End Reaction

W3- L Curve (or Table) gives Load Carrying Capacity for the Nominal Strength for Shear (Vn) only on end support (e), always without attached transverse web stiffeners provided. 1999 AISI Supplement gives reduction coefficient qs to multiply Vn.for C sections with holes. W4 - Shear or Shear + Bending for Interior Reaction

W4- L Curve (or Table) gives Load Carrying Capacity for the Nominal Strength for Shear (Vn) only or Combined Shear and Bending, on interior support, (i), always without attached transverse web stiffeners provided. Program chooses minor value for

W4, and indicates it and also which the governing cause is, on Tables. When laps are considered, as lap lengths are limited, Shear values for one web are dominating. W5 - Web Crippling for End Reaction

W5- L Curve (or Table) gives Load Carrying Capacity for the Nominal Strength for Web Crippling (Pn), only on end support (e), for EOF (End One Loading) according to Section C3.4. For the end support of a Z-shape, if the flange is bolted, and both the support and the section satisfied the requirements at 3.4, Pn value would be increased, multiplied by 1.3. W6 - Web Crippling or Web Crippling + Bending for Interior Reaction

W6- L Curve (or Table) gives Load Carrying Capacity for the Nominal Strength for Web Crippling (Pn), only or Combined Web Crippling and Bending, on interior support, (i) for IOF (Interior One Flange Loading) according to Section C3.4. Program chooses minor value for W6, and indicates it, and also which the governing cause is, on Tables. For the support point of two nested Z-shapes, if all required conditions at C.3.5.1 were satisfied, Load Carrying Capacity would be increased. For calculating W5 and W6, different equations are given on Table 3.4-1, by 1996 AISI Specifications, for single Unreinforced Webs, or for I (two C connected back to back according to D1.1) and similar sections. 1999 AISI Supplement gives reduction coefficient Rc to multiply Pn for C sections with holes. Web Stiffeners built according to Art. B6-1, at each support (Se or/and Si) are optional tools for eliminating Crippling problem. Program advices the economic lengths for the beam, in order to use the web stiffeners at each support. W7 - Equivalent for Maximum Deflection

W7- L Curve (or Table) gives optionally the Equivalent Uniform Load Carrying Capacity for an imposed Maximum Deflection service condition, as a fraction of the span Length (e.g. L/240). For LRFD Method Load Factor is assumed equal to 1.50, by default. W8 - Equivalent to Construction Load

W8- L Curve (or Table) gives optionally the Equivalent Uniform Load for an imposed Concentrated Construction Load= 1KN or 0,22 kips applied at the worst situation, and as a service condition. For LRFD Method Load Factor is assumed equal to 1.40, by default. Mnb= Nominal Flexural Moment Mnb-L Curve gives optionally the Nominal Strength for Bending with lateral buckling versus the span length, for any or none lateral restriction. For example, if User fixes Cb=1 with free flanges and no bracings, for C and Z shapes, with Fy=33ksi and Fy=50ksi steels, He obtains Chart II-1a to 2b from the AISI 96 Design Manual.

Appendix

Appendix A According to AISI 2001 Specification, Chapter C3.1.3.

The reduction factor, R, shall be limited to roof and wall systems meeting the following conditions: 1) Member depth less than 11.5 in. (292 mm) 2) Member flanges shall have edge stiffeners 3) 60 ≤ depth/thickness ≤ 170 4) 2.8 ≤ depth/flange ≤ 4.5 5) 16 ≤ flat width/thickness of flange ≤ 43 6) For continuous span systems, the lap length at each interior support in each

direction (distance from center of support to end of lap) shall not be less than 1.5d. 7) Member span length shall be no greater than 33 feet (10 m) 8) For continuous span systems, the longest member span length shall not be more

than 20% greater than the shortest length. 9) Both flanges shall be prevented from moving laterally at the supports. 10) Roof or wall panels shall be steels sheets with 50 ksi (640 MPa or 3520 kg/cm2)

minimum yield point, and a minimum of 0.018 in. (0.46 mm) base metal thickness, having a minimum rib depth of 1-1/4 in. (32 mm), spaced a maximum of 12 in. (305 mm) on centers and attached in a manner to effectively inhibit relative movement between the panel and purlin flange.

11) Insulation shall be glass fiber blanket 0 to 6 in. (152 mm) thick compressed between the member and panel in a manner consistent with the fastener being used.

12) Fastener type: minimum no. 12 self-drilling or self-tapping sheet metal screws of 3/16 in. (4.76 mm) rivets, having washers ½ in. (12.7 mm) diameter.

13) Fasteners shall not be standoff type screws. 14) Fasteners shall be spaced not greater than 12 in (305 mm) on centers and placed

near the center of the beam flange, and adjacent to panel high rib. 15) The design yield point of the member shall not exceed 60 ksi (410 MPa or 4220

kg/cm2).

Appendix B According to AISI 2001 Specification, Chapter C3.5.1. The following conditions shall be satisfied: 1) The ends of each section shall be connected to the other section by a minimum of

two ½ in. (12.7 mm) diameter A307 bolts trough the web. 2) The combined section shall be connected to the support by minimum of two ½ in.

(12.7 mm) diameter A307 bolts trough the flanges. 3) The webs of two sections shall be in contact. 4) The ratio of the thicker to the thinner part shall not exceed 1.3.