SGWIN

SPACE GASS Reference ManualVersion 9.0

23rd Edition, February 2003

Integrated Technical Software

[email protected]

SPACE GASS Reference Manual

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Table of Contents

Introduction 10

How to use this manual 11

Legal notice 15

Hardware requirements 19

Product support 20

Hardware locks and insurance 21

Installation and configuration 22

Installing SPACE GASS 23

Configuring SPACE GASS 24

Folders and files 25

Text formatting 27

General configuration 29

Graphics dimensions 32

Graphics colors 34

General colors 35

Problem size limits 36

Steel connection configuration 37

Getting started 42

Starting SPACE GASS 43

The main SPACE GASS window 44

Using the mouse 46

Dialogue boxes 47

Data entry 49

Managing job files 52

Starting a new job 53

Opening a job 54

Saving a job 55

Deleting a job 56

Cleaning up a job 57

Job status 58

The status line 59

The menu system 62

The file menu 63


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The structure menu 65

The loads menu 67

The analysis menu 68

The design menu 69

The output menu 70

The view menu 71

The query menu 72

The settings menu 73

The config menu 75

The window menu 76

The help menu 77

The toolbars 78

The left side toolbar 79

The top toolbar 80

Modelling the structure 81

Coordinate systems 82

Sign conventions 84

Symmetrical structures 87

Ill-conditioning and instabilities 88

Analysis data 89

Units 90

Headings 92

Node data 93

Member data 95

Node restraint data 100

Section property data 103

Standard section libraries 106

Shape builder 107

Flipping a section 109

Column and beam Tee sections 110

Angle sections 111

Material property data 113

Master-slave constraint data 115

Member offset data 123

Node load data 125

Prescribed node displacement data 126

Member concentrated load data 128


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Member distributed force data 130

Member distributed torsion data 132

Thermal/prestress load data 134

Self weight data 136

Combination load case data 137

Load case title data 140

Lumped mass data 141

Spectral load data 144

Spectral curve editor 146

Importing a spectral curve 148

Area loading data 149

Text file input 150

Text file format 151

Initiator 152

Headings text 153

Nodes text 154

Members text 155

Node restraints text 157

Section properties text 158

Material properties text 160

Master-slave constraints text 161

Member offset text 162

Node loads text 163

Prescribed node displacements text 164

Member concentrated loads text 165

Member distributed forces text 166

Member distributed torsions text 167

Thermal/Prestress loads text 168

Self weight text 169

Combination load cases text 170

Load case titles text 171

Lumped masses text 172

Spectral loads text 173

Steel member design text 174

Steel connection design text 176

Terminator 179

Text file errors 180

Text file example 185


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Structure wizard 189

Datasheet input 192

Using datasheets 193

Graphics 198

Graphics overview 199

Floating menus 202

Graphical input 204

Graphical editing 207

Using the keyboard to position points 209

Multiple viewports 210

Node properties 212

Member properties 215

Node restraints 219

Section properties 220

Material properties 221

Master-slave constraints 222

Member offsets 223

Draw 224

Move 225

Rotate 227

Copy 228

Mirror 230

Delete 231

Stretch 232

Scale nodes 233

Generate arc 234

Sub-divide 235

Intersect 237

Generate taper 239

Renumber 241

Select all 243

Node loads 244

Prescribed node displacements 246

Member concentrated loads 248

Member distributed forces 250

Member distributed torsions 252

Thermal/prestress loads 254


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Self weight 256

Combination load cases 257

Load case titles 258

Lumped masses 259

Spectral loads 261

Area loading 262

Managing load cases 264

Steel members 265

Steel connections 267

View nodes / members 270

View node and member properties 271

View global origin 272

View local axes 273

View full 3D member geometry 274

Labelling and annotation 278

View diagrams 279

View envelope 280

View dynamic mode shapes 281

View buckling mode shapes 283

View steel member design groups 284

View steel member top flanges 285

View steel member flange restraints 286

View steel member design results 287

View steel connection drawings 289

Redraw 291

Zoom 292

Pan 293

Scales 294

Find 295

Filters 297

Views 300

Viewpoint 302

Query frame 304

Query analysis results 305

Query steel member design results 307

Grid 308

Snap 309

Ortho 310

Attach 311


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Plane 313

Coordinates 314

Aperture size 315

Crosshair size 316

Curved line resolution 317

Bending moment diagrams sign 318

Diagram shading 319

Analysis 320

Static analysis 321

Displacements, forces, moments and reactions 323

P-D effect (big) 324

P-d effect (little) 325

Axial shortening 326

Tension-only and compression-only effects 327

Cable members 328

Non-linear analysis procedure 331

Static analysis buckling 333

The wavefront optimizer 334

The wavefront analysis method 339

A quick frontwidth calculation method 340

The wavefront method in more detail 341

Running a static analysis 342

Dynamic frequency analysis 347

Modelling considerations 348

Natural frequencies, periods and mode shapes 349

Running a dynamic frequency analysis 350

Dynamic response analysis 354

Dynamic response 355

Spectral data 356

Spectral curves and load cases 357

Running a dynamic response analysis 359

Buckling analysis 364

Buckling effective lengths 366

Special buckling considerations 367

Running a buckling analysis 369

Analysis warnings and errors 371

Steel member design 375


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Steel member design data 377

Steel member design sign conventions 387

Member groups 388

Flange restraints 393

Column and beam Tees 400

Running a steel member design 401

Updating member sizes 406

Constraining members to the same final design size 407

Serviceability check 408

The steel member design/check process 409

Design groups and intermediate stations 410

Design segments 411

Section check 412

Member check 413

Critical flange 414

Effective flange restraints 415

Twist factor 417

Load height factor 418

Lateral rotation factor 419

End moment ratios and other factors 421

Eccentric effects for compression members 422

Eccentric effects for tension members 423

The code check 424

Steel member design/check assumptions 425

Steel member design/check errors 431

Steel connection design 434

Steel connection design data 436

Running a steel connection design 444

The steel connection design process 447

Connection geometry 448

Haunches 449

Design actions 450

Minimum design actions 451

Design phase 452

Check phase 453

Bolts 454

Welds 455

Plates and cleats 456


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Tension and compression stiffeners 457

Shear stiffeners 459

Clashing and copes 460

Baseplate connections 461

Critical load case 462

Steel connection design errors 463

Concrete column design 472

Running a concrete column design 473

Concrete column configuration 481

Concrete column assumptions and notes 483

Output 485

Frame analysis report 486

The status report 490

The bill of materials report 491

Centre of gravity 492

Dynamic frequency output 493

Dynamic response output 494

Buckling analysis output 496

Steel design report 497

Steel member design section, member and shear check results 501

Steel member design zero variables 502

Steel connection design critical load case 503

Graphics hardcopy 504

Concrete design report 506

CAD interface module 507

Exporting data from SPACE GASS to CAD 509

Elevations, plans, cross sections, 2D views, 3D models and schedules 510

Steel connection details 513

Importing data from CAD to SPACE GASS 514

Standard libraries 515

The library editor 517

Section libraries 520

Material libraries 523

Bolt libraries 524

Plate libraries 525


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Weld libraries 526

Reinforcing bar libraries 527

Spectral curve libraries 528

Portal frame analysis 529

Geometry and loads 530

Method of input 535

Analysis procedure 537

Analysis results 538

Graphical output 539

Analysis input report 543

Static analysis report (itemised) 553

Static analysis report (enveloped) 563

Bill of materials report 568

Dynamic frequency analysis report 569

Dynamic response analysis report 570

Buckling analysis report 571

Portal frame member design 573

Member design results 577

Steel member design report 578

Portal frame connection design 586

Connection design results 589

Steel connection drawings 590

Steel connection design report 591

Cable analysis 597

Method of input 599

Analysis procedure 600

Analysis results 601

Converting old jobs 606

Bibliography 607


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Introduction

SPACE GASS is a general purpose structural analysis and design program for 2D and 3D frames,trusses, grillages and beams. It includes a full complement of features that make it suitable forany job from small beams, trusses and portal frames to large high rise buildings, towers andbridges.

Its emphasis on graphics means that you easily see the status of your model at all times. In fact,the extensive range of graphical editing features allow you to input your model or make changesentirely within the graphical editor. Of course, if you prefer to work with datasheets or othermethods of input then they are available too.

A structure wizard automatically generates the initial data for many typical structures which youcan then manipulate to create the exact model you want.

State of the art solvers for linear and non-linear static analysis, dynamic analysis and bucklinganalysis are available. Steel and concrete design modules for various international codes ofpractice are also available.

Graphical and text reports can be generated for any parts of the structural model. Comprehensivefilters that can be defined graphically allow you to customize your graphical views and outputreports to include just want you want to see.

Although SPACE GASS is a comprehensive program with many advanced features, its logicalmenu structure, toolbars and graphical emphasis makes it easy to learn and use, even for first timeusers. If you have questions or need help then you will probably find the answers in this manual.


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How to use this manual

Illustrated as follows is an example of each of the three outline styles used in this manual. Thesestyles are designed to draw your attention to information in one of three ways: as a hint, animportant note or general note.

Hints are non-essential, but useful, pieces of information which will improve your understandingof the program. Hints sometimes identify a special way of doing something and are typicallyquite specific.

Important notes should be carefully read and understood. They outline information that is vital tothe effective use of the software.

Notes identify articles of information which are meant as an aside to aid your understanding ofSPACE GASS. Some notes are quite general in nature and do not give reference to a specificprocedure. Notes may also serve to draw your attention to specific interpretation.

HINTS

This is an example of the SPACE GASS HINTS style and icon.

IMPORTANT NOTE

! IMPORTANT NOTE !

This is an example of the SPACE GASS important note style and icon.

NOTES

This is an example of the SPACE GASS NOTES style and icon.

Following is a brief overview of each section in the manual.

Chapter 1 "Installation and Configuration"

Deals with the installation and configuration of SPACE GASS. Once the software is installed andrunning correctly, you should not have to refer to this chapter again.


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Chapter 2 "Getting Started"

If you are new to frame analysis programs or Windows programs in general, then you should readthis chapter before attempting to run a job. It provides very good basic information that you willneed to know about the operation of SPACE GASS.

Chapter 3 "Modelling the Structure"

Discusses the basics of how you can model a structure with SPACE GASS and includesinformation on nodes, members, restraints, coordinate systems, sign conventions, etc.

Chapter 4 "Analysis Data"

Gives a detailed description of each type of data that can be used in the frame analysis part of themodel. Data for steel and concrete design is not included (see later chapters). This chapter dealsonly with the data itself, and leaves the discussion of the numerous methods that you can use toinput the data to later chapters.

Chapter 5 "Text File Input"

Describes the format of standard SPACE GASS text files. This is one of the five methods of dataentry. You can type your data into a standard text file and then import it into SPACE GASS.Standard text files can also be used as an alternative for permanent storage of data.

Chapter 6 "Structure Wizard"

Another method of input involves selecting from a number of standard structures, answering afew simple questions about the structure selected, and then having the structure wizard generateall of the frame data for you. Any of the other data entry methods can be used to modify the dataafter it has been generated using this method.

Chapter 7 "Datasheet Input"

Is a modified form of spreadsheet input which allows you to input or edit any parts of the framedata or steel design data. Along with graphical input, this is probably one of the most useful andversatile methods of data entry.

Chapter 8 "Graphics"

Covers all of the graphics facilities available. This includes graphical structure input, graphicalload input, graphical steel design input, connection drawing detail, graphical output of loading,displacement, bending moment, shear force, stress, axial force and animated mode shapediagrams. Full descriptions are also given for the many commands associated with drawing,moving, copying, rotating, mirroring, erasing, zooming, panning, scaling, coordinate systems,changing the viewpoint, labelling, querying diagrams, viewing the full 3D geometry of members,hidden line removal, renumbering, etc.

Chapter 9 "Analysis"

The static, dynamic and buckling analysis modules, together with their options and controlparameters are fully described here.


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Chapter 10 "Steel Member Design"

Details the use of the steel member design module. Please pay particular attention to theprocedures and assumptions listed near the end.

Chapter 11 "Steel Connection Design"

Details the use of the reinforced concrete column design module. Please pay particular attentionto the procedures and assumptions listed near the end.

Chapter 12 "Concrete Column Design"

Details the use of the reinforced concrete column design module.

Chapter 13 "Output"

Describes the types of output reports and graphics hardcopies that can be obtained and the optionsthat are available for sorting, formatting, enveloping, positioning on the page, etc.

Chapter 14 "Cad Interface Module"

Describes the CAD interface and how drawing files in DXF format can be imported or exported.

Chapter 15 "Standard Libraries"

SPACE GASS is supplied with a number of standard section, material, bolt, plate and weldlibraries. This chapter provides a complete guide on how you can customise any of these libraries,or create your own section libraries.

Appendix A "Portal Frame Analysis"

Presents a detailed report on the analysis of a typical steel portal frame. Full discussions regardingthe input data and the decisions involved in producing it are included, together with completeprintouts of the analysis input and output reports.

Appendix B "Portal Frame Member Design"

Presents a detailed report on the member design for the steel portal frame analysed in appendix B.It includes a discussion on how the steel members are being modelled, together with completeprintouts of the member design input and output reports.

Appendix C "Portal Frame Connection Design"

Presents a detailed report on the connection design for the steel portal frame analysed in appendixB. It includes a discussion on how the steel connections are being modelled, together withcomplete printouts of the connection design input and output reports.


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Appendix D "Cable Analysis"

Presents a worked example demonstrating the input and analysis of a 30m tall, guyed mast. Thecatenary cable equations are used to calculate the axial force in a nominal guy member, this isthen compared to the result obtained from SPACE GASS.

Appendix E "Converting Old Jobs"

Explains how you can convert data files that were produced with SPACE GASS v1, v2 or v3 forloading into the latest version. Note that data files produced with SPACE GASS 4 or later areautomatically converted into the latest format when they are opened.

Appendix F "Bibliography"

A list of references.


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Legal notice

End User License Agreement

Notice to Licensee:

This End User License Agreement (the "Agreement") is a legal agreement between you and I.T.S.Integrated Technical Software Pty Ltd (ACN 086 605 567) ("ITS"), a registered company underthe Corporations Law of the State of Victoria, Australia. BY USING THIS PRODUCT, YOUAGREE TO BE BOUND BY THE TERMS AND CONDITIONS OF THIS AGREEMENT. Ifyou do not agree to all the terms and conditions of this Agreement or if you do not have theauthority to agree to all the terms and conditions of this Agreement on behalf of the licensee thenyou MUST NOT USE THE PRODUCT. Provided the Product has not been used and is not aloan, student or evaluation version, you may return it to your place of purchase for a full refund.

1. Definitions. For the purposes of this Agreement, the following terms shall have the followingmeanings:

1.1 "Product" shall mean and include the SPACE GASS software, updates, CDs,computer disks, Security Devices, help files, reference manual or other instructions,technical support or any other software, items or information of any kind provided by ITSor obtained from the www.spacegass.com web site.

1.2 "Software" shall mean all software included in the Product.

1.3 "Security Devices" shall mean and include hardware or software that limits thenumber of users that may operate the Software simultaneously, or imposes an ExpiryDate beyond which the Software cannot be used, or prevents certain parts of the Softwarefrom being used.

1.4 "Expiry Date" shall mean the date imposed by any Security Devices beyond whichthe Software cannot be used.

1.5 "ITS" includes its employees, agents and suppliers.

2. License. The Product is protected by copyright laws and international copyright treaties, aswell as other intellectual property laws and treaties. The Product is licensed, not sold.

2.1 Grant of License. Subject to the terms and conditions of this Agreement, ITS grantsto you a non-exclusive license to use the Product during the term of this Agreement.

2.2 User Limit. The Software may be installed on an unlimited number of computers,however the maximum number of users operating it simultaneously may not exceed theuser limit imposed by the Security Devices.


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2.3 Reference Manual. You may make such copies of the reference manual as arereasonably necessary for your use of the Product by the permitted number ofsimultaneous users, but you may not make copies of the reference manual for any otherpurpose without the prior written consent of ITS.

3. Ownership; Proprietary Rights. ITS shall at all times be the owner of and have all rights tothe Product, and all intellectual property associated therewith, including but not limited to patents,copyrights, trade names and marks, domain names, and trade secrets related thereto. The Productis protected by copyright laws and international treaty provisions. Nothing herein shall cause orimply a sale, license or transfer of any intellectual property rights of ITS to you or to any thirdparty, except as expressly set forth herein. You may not reverse engineer, decompile,disassemble, or otherwise attempt to discover the source code of the Software. You may notattempt to reverse engineer, duplicate or bypass any Security Devices.

4. Disclaimers. ITS makes no warranties or representations as to the Product to you or to anyother party. To the extent permitted by applicable law, all implied warranties, including, but notlimited to, the implied warranties of merchantability and fitness for a particular purpose, arehereby disclaimed.

5. Limitation of Liability. To the maximum extent permitted by applicable law, in no event shallITS be liable for any punitive, exemplary, consequential, indirect, incidental, or special damagesarising from or related to the use of the Product by any party, including without limitationdamages arising from loss of data, loss of revenue or profits or failure to realize savings or otherbenefits, even if ITS has been advised of or should be aware of the possibility of such damages.In the event of any defect in the Product ITS may, at its option;

(i) replace the Product or supply its equivalent;

(ii) repair the Product;

(iii) pay for the cost of replacing the Product or of acquiring its equivalent; or

(iv) pay for the cost of having the error in the Product rectified.

To the extent that the Product involves providing a service, in the event of any error or defect inthe provision of that service ITS may, at its option;

(i) supply the service again; or

(ii) pay for the cost of having the service supplied again.

Because some states and jurisdictions do not allow the exclusion or limitation of liability, theabove limitation may not apply to you.

6. Indemnification. You, at your sole expense, will defend, indemnify and hold ITS harmlessfrom and with respect to any loss or damage (including reasonable attorneys fees and costs)incurred in connection with, any suit or proceeding brought by a third party against ITS insofar assuch suit or proceeding shall be based upon (i) any claim arising out of or relating to your use of


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the Product except where such claim alleges that the Software infringes or constitutes wrongfuluse of any copyright, trade secret, patent or trade mark of any third party; or (ii) any claim arisingout of or relating to any act or omission by you. You will pay any damages and costs assessedagainst ITS (or paid or payable by ITS pursuant to a settlement agreement) in connection withsuch a suit or proceeding.

7. Changes to the Product. ITS may change the Product from time to time without notice to youand shall not be under any obligation to provide you with any notification of such change.

8. Non-Transferability. You may not rent, lease, sub-license, lend or transfer the Product toanother person or legal entity without the prior written consent of ITS.

9. Term and Termination. The term of this Agreement shall commence on the date that youinstall or use the Product and shall continue (unless earlier terminated as provided herein) untilthe Expiry Date, or in perpetuity if no Expiry Date is imposed. Without prejudice to any otherrights, ITS may terminate this Agreement at any time if you fail to comply with its terms andconditions.

Upon termination of this Agreement for any reason whatsoever, you shall cease all use of theProduct and remove all copies of the Software from your computers.

10. General.

10.1 Assignment. You may not assign or transfer this Agreement or any of your rights,duties or obligations hereunder and this Agreement may not be involuntarily assigned orassigned by operation of law, without the prior written consent of ITS, which consentmay be granted or withheld by ITS in its sole discretion.

10.2 Severability. Each provision of this Agreement is intended to be severable. If anycovenant, condition or other provision contained in this Agreement is held to be invalidor illegal by any court of competent jurisdiction, such provision shall be deemedseverable from the remainder of the Agreement and shall in no way affect, impair orinvalidate any other covenant, condition or other provision contained in this Agreement.If such covenant, condition or other provision shall be deemed invalid due to its scope orbreadth, such covenant, condition or other provision shall be deemed valid to the extentof the scope or breadth permitted by law.

10.3 Governing Law. You agree that the use of the Product by you shall be governed bythe laws of the State of Victoria and the Commonwealth of Australia, and you consent tothe non-exclusive jurisdiction of the courts of that State and the Commonwealth.

10.4 Attorneys Fees. If any legal action is brought arising out of or relating to thisAgreement, the prevailing party shall be entitled to receive its reasonable attorneys feesand court costs in addition to any other relief it may be entitled.


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10.5 Entire Agreement. This Agreement is the complete and exclusive statement of theagreement of the parties hereto with respect to the subject matter hereof, and supercedesall prior and concurrent agreements, promises, proposals, representations and warranties,oral or written, with respect to the subject matter hereof.


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Hardware requirements

IBM 386/486/Pentium or compatible.

Windows 95/98/ME/NT/2000/XP.

Minimum 8Mb RAM.

Hard disk with at least 30 Mb free space.

800x600 graphics resolution or better running 256 colors.

Any printer or plotter including postscript devices supported by Windows.

Microsoft mouse or other Windows pointing device.

Math co-processor.


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Product support

Product support includes:

Notification of any program modifications or enhancements as they become available.

Update facility for those users wishing to upgrade to the latest version.

Replacement of any software which is found to be defective through no fault of the user orwhich does not conform to the general published function of the software.

Telephone, facsimile and email support by I.T.S. or an authorised dealer.

Comprehensive Internet web site providing latest information, drivers, updates, libraries,etc. for all registered SPACE GASS users.

I.T.S. reserves the right to charge for telephone, facsimile or email support.


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Hardware locks and insurance

SPACE GASS is usually supplied with a hardware lock that must be inserted into the parallel orUSB port before the software will run. If the hardware lock is faulty or becomes damaged ordestroyed, it can be replaced for a nominal fee provided that a remnant of the lock showing avalid serial number can be produced proving that it is a genuine SPACE GASS hardware lock.

The hardware lock cannot be replaced for a nominal fee if it is lost or stolen and, for this reason,it is recommended that the user insure the software package and hardware lock for the full currentmarket value of the software.


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Installation and configuration

Installation and configuration of SPACE GASS is a simple two-stage process that is explained inthe following sections.


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Installing SPACE GASS

Insert the SPACE GASS CD and then follow the instructions that appear on the screen.Alternatively, if you have downloaded the program from the SPACE GASS website then just runthe file that you downloaded. If you have any problems, refer to the README.TXT file on theCD or in the folder that you are installing SPACE GASS into.


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Configuring SPACE GASS

You can now run SPACE GASS by double-clicking on the SPACE GASS icon which has beencreated.

When you first start SPACE GASS, or if you make any changes to your system, you will beprompted for some configuration information.

After the initial configuration, you can change any of the configuration settings by selecting themfrom the Config menu. The eight configuration forms are detailed in this chapter.

All configurable data is stored in a file called SG.INI which is stored in the "Start in" folder (viewthe SPACE GASS icons properties to determine the "Start in" folder).


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Folders and files

Select "Folders and files" from the Config menu.

This dialogue allows you to set the folder locations for the SPACE GASS program itself and forthe various types of data files.

Main program folder

Contains the SPACE GASS program itself.

Main data folder

Contains the main job data files.

Library folder

Contains the standard section, material, bolt, plate, weld, spectral curve and reinforcing barlibraries. This normally matches the main program folder, however it can be different if you wishto have the library files in a separate folder.

Text data folder

Contains import/export text data files and print text files.


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Backup data folder

Contains import/export backup job data files.

Archive data folder

Contains import/export archive data files.

CAD data folder

Contains import/export CAD data files.

Temporary data folder

Contains temporary files that are created and deleted by SPACE GASS as it operates.

Documents folder

Contains MS-Access, MS-Excel and MS-Word document files.

Text editor program

The name of the SPACE GASS text editor. This can be the standard Windows NOTEPAD or anyother text editor that runs in Windows.

Calculator program

The name of the SPACE GASS calculator. This can be the standard Windows calculator or anyother calculator that runs in Windows.

Default sections library

The name of the default section library.

Note that any folders that do not exist are automatically created as you go.


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Text formatting

Select "Text formatting" from the Config menu.

This dialogue allows you to set the report and graphics text formats, margins and fonts.

Report text format

The report text format which is initially selected when you create a new job. Note that this settingdoes not change the current job. The report text format for the current job can only be changedfrom the Frame Analysis Report dialogue (selected from the Output menu).

Graphics text format

The graphics text format which is initially selected when you create a new job. Note that thissetting does not change the current job. The graphics text format for the current job can only bechanged from the Labelling and Annotation dialogue (selected from the View menu).

Report margins

The top, bottom and left margins for text reports.


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Report font

The font for text reports. This must not be a proportional font otherwise the columns of numbersin reports will not line up properly. The two-column output toggle switches between one-columnand two-column output in the report.

Screen graphics font

The font for screen graphics text. This can be any proportional or fixed font.

After setting the screen graphics font size, if the text on theSPACE GASS graphics screen looks too big or too small, it may be because the screen graphicscorrection factors have not been set correctly. Refer to "Correction factors" in "Graphicsdimensions" later in this chapter.

Printer graphics font

The font for printer graphics text. This can be any proportional or fixed font.

Plotter graphics font

The font for plotter graphics text. This can be any proportional or fixed font.


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General configuration

Select "General configuration" from the Config menu.

This dialogue allows you to set the general purpose configuration items in SPACE GASS.

Sound on alert

This allows you to suppress or enable the sound that the program makes when it wants to alertyou to something.

Sound on error

This allows you to suppress or enable the sound that the program makes when an error occurs.

Diagram shading

Loading, bending moment, shear force, stress and axial force diagrams are shaded if this item ischecked. This is the setting which is initially selected when you create a new job. It does notchange the current job. The diagram shading for the current job can only be changed from theSettings menu.

Shading is normally turned off as it makes multiple superimposed diagrams hard to read.


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Check disk space

If this item is checked, SPACE GASS performs a disk space check to ensure that there is enoughfree space for a static or dynamic analysis to proceed to completion. If the disk space check hasbeen disabled and there is not enough space for the analysis data, the program may abort with anerror message. Although this is not a desirable occurrence, it will not result in loss of data.

Vertical axis

The graphics vertical axis which is initially selected when you create a new job. Note that thissetting does not change the current job. The graphics vertical axis for the current job can only bechanged from the Viewpoint dialogue (selected from the View menu).

Changing this setting only affects the graphics display. It doesnt affect the local axis definitions,the steel design top flange definitions, or the analysis and design modules in any way.

Aperture size

The size of the aperture circle which appears when nodes and/or members can be selectedgraphically. This is the setting which is initially selected when you create a new job. It does notchange the current job. The aperture circle size for the current job can only be changed from theSettings menu.

Crosshair size

The size of the crosshair which appears when snap or ortho modes are on. This is the settingwhich is initially selected when you create a new job. It does not change the current job. Thecrosshair size for the current job can only be changed from the Settings menu.

Curve resolution

The curve resolution which is initially selected when you create a new job. Note that this settingdoes not change the current job. The curve resolution for the current job can only be changedfrom the Settings menu.

All curved lines drawn with SPACE GASS are actually a series of short straight lines. In mostcases it is very difficult to differentiate between a true curve and a series of ten straight linesegments placed around the curve. SPACE GASS allows you to specify how many straight linesegments per member are used to approximate curved lines in displacement, bending moment,shear force or axial force diagrams.

Bending moment diagrams sign

The bending moments sign which is initially selected when you create a new job. Note that thissetting does not change the current job. The bending moments sign for the current job can only bechanged from the Settings menu.

The convention for drawing bending moment diagrams varies from country to country. SPACEGASS can be configured to draw bending moments on either the tension or compression side of amember.


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Dashed lines

Dashed (broken) lines are used to differentiate between load cases and between diagram types.All lines are drawn continuous if dashed lines are not allowed.

DXF layer names

Layer names are only applicable if you have the CAD interface module. These are the layers intowhich the drawing will be placed when you transfer it into your CAD program. AutoCAD acceptsmost names, while AutoSKETCH accepts only integer values from 1 to 10.

It is recommended that you make each layer name different so that it is easy to distinguishbetween centrelines, text, members, hidden lines, attributes, bolts, plates and cut-off lines. It isalso recommended that you set the hidden line layer in your CAD software to dashed or dottedlines.


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Graphics dimensions

Select "Graphics dimensions" from the Config menu.

This dialogue allows you to set graphics correction factors, and printer/plotter orientation,dimensions and origin locations.

Correction factors

Some graphics screens, printers and plotters exaggerate the horizontal and/or vertical scales sothat the SPACE GASS graphical output appears stretched or compressed in either or bothdirections. SPACE GASS allows you to apply correction factors which allow for theseexaggerations and adjust the graphical output so that it is correctly sized and proportioned.

If you click on the Measure button, you can simply measure the width and height in millimetresof two lines on the screen with a ruler, and SPACE GASS calculates the correction factors foryou.

! IMPORTANT NOTE !

Ensure that you measure between the arrow heads rather than measuring the overall dialogue orscreen size, otherwise items on the SPACE GASS graphics screen will appear too small or toolarge.


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Printer/plotter orientation

It is possible to configure SPACE GASS so that graphical output on your printer and/or plotter isrotated through 90 (landscape). Note that if you specify landscape, only the structure andlabelling inside the graphics border is rotated. The border around the graphics output is notaffected. Thus, a landscape hardcopy uses exactly the same page space as a portrait hardcopy.

Printer line width

This lets you control the thickness of lines in the printer graphics output.

Printer/plotter size

The printer and plotter graphics width and height settings allow you to control the size of thegraphical output that you get. Do not use widths and heights larger than the actual paper size thatthe device can handle otherwise part of the image will be lost.

Printer/plotter origin offset

The printer and plotter graphics origin offsets allow you to move the graphical output to anydesired position on the sheet. Origin offsets of zero cause the graphical output to be positioned inthe corner of the page for most printers and plotters.


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Graphics colors

Select "Graphics colors" from the Config menu.

This dialogue allows you to select colors for screen, printer and plotter graphics output.

Colors are selected by first clicking on the item to be changed and then selecting a color from thepalette at the bottom of the dialogue.

The list of color indexes next to "Section properties" represents section properties 1-25. If youhave more than 25 section properties, the pattern is repeated for properties 26-50, 51-75, etc.

The list of color indexes next to "Load cases" represents the first 25 load cases. If you have morethan 25 load cases, the pattern is repeated for each additional group of 25 load cases.


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General colors

Select "General colors" from the Config menu.

This dialogue allows you to set the Windows color scheme. It controls items such as dialoguecolors, button colors, scroll bar colors, etc.

When you select this option SPACE GASS loads the standard Windows color selection dialoguewhich can also be selected from the Windows Control Panel. The appearance of this screen isdependant upon the version of Windows you are running.


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Problem size limits

Select "Problem size limits" from the Config menu.

This dialogue allows you to set maximum job size limits.

SPACE GASS has been dimensioned dynamically. This allows it to expand into the availablememory of your computer giving you virtually unlimited problem size capacity dependant onlyon the memory capacity of your computer.

The size limits you set allow you to reserve space for a job, with space being allocated accordingto the size of each component of a job. You should set the limits high enough so that there isenough capacity for the largest of jobs that you are likely to encounter but small enough that youdon't exceed the memory capacity of your computer.

Keep in mind that the limits can be changed at any time, even when you are halfway throughinputting a job and find that you have run out of capacity. Just select "Problem size limits" fromthe Config menu and change the limits to suit your job size. After changing the limits you cansimply return to where you left off, with all previously entered data retained.


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Steel connection configuration

Select "Steel connection configuration" from the Config menu.

This dialogue allows you to change the default steel connection design settings.

Some of the items are purely global settings which apply to all connections during a design. Theycan only be changed here and do not form part of the individual data for a connection. The otheritems above are also global settings which can be changed here, but which can also be redefinedindependently for each connection to be designed. They are, in effect, the default values for theindividual connection design parameters.

The idea is to set the configuration defaults to the most common settings to suit your situation.This reduces the amount of data required for each connection because, for most connections, thedefault data will suffice. Naturally, there are some items such as connection type, boltingprocedure and haunch details, etc. for which defaults are of no use. These must be definedindividually for each connection.


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Strength grades

The strength grades for bolts, welds, plates, cleats, seats and members can be set to normal orhigh. The actual yield strengths are taken from the standard section, bolt, plate and weld librariessupplied with SPACE GASS. All of these libraries can be viewed, modified, or appended asrequired (see also Standard libraries).

Bolt, weld, and plate size ranges

The four size ranges for snug bolts, tensioned bolts, fillet welds and plates are limits within whichthe connection program will work during the design phase. Note that the weld and plate sizeranges do not apply to stiffener welds or plates. It is possible to partially simulate a connectioncheck (as opposed to a design where all sizes are unknown) by setting some or all of the rangesetting's minimums and maximums to the actual known sizes.

Bolt slip factor

A measure of the friction sliding resistance between two surfaces bolted together. For clean,rolled sections or plates a slip factor of 0.35 is common. For finished or machined surfaces theslip factor must be determined by testing.

Bolt prying factor

A coefficient to allow for the additional tensile force in a bolt due to prying. The prying factor isnormally in the range 0.2 to 0.33.

Edge distance factor

The minimum distance from a bolt centreline to the edge of a section or plate. AS4100/NZS3404recommends edge distance factors of 1.75 for sheared or hand flame cut edges, 1.5 for rolledplate, machine flame cut, sawn or planed edges, or 1.25 for rolled edges of rolled sections.

Bolt gauge and pitch

The bolt gauge is the centreline distance between adjacent gauge lines (columns of bolts), whilethe bolt pitch is the centreline distance between adjacent bolts along a gauge line.

Note that in most connections, the gauge lines run perpendicular to the axis of the supportedmember. For the bolts in the seat component of an angle seat connection, however the gauge lineand pitch directions are interchanged.


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Connection dimensions

Flange to bolt clearance

The minimum distance from the centreline of an end plate bolt to the edge of the flange to whichthe end plate is welded (C4 in the diagram above). It applies to bolted end plate, apex andmoment baseplate connections. For example, for a bolted end plate connection and, consideringthe bolts above the top flange of the supported beam, the flange to bolt clearance is the distancefrom the top of the beams top flange to the centreline of the bolts above it.

Beam end clearance

The distance from the end of the supported member to the face of the supporting member (C3 inthe diagram above). This setting is ignored when an end plate is involved because the thickness ofthe end plate determines the distance between the two members.

Coped flange clearance

The minimum distance from the edge of the flange of the uncoped member to the end of the cope(C1 in the diagram above).

Minimum cope depth

The minimum depth of the cope, aligned with the axis of the coped member (C2 in the diagramabove).

Stiff seat bearing length

The flange bearing length parallel to the supported member longitudinal axis used for stiff seatconnections. If the connection has a steel supporting member (as opposed to a brick or concretesupport of unknown dimensions), the stiff seat bearing length can be left at zero and it will becalculated automatically during the design phase based on the dimensions of the supportingmember.


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Preferred bolt rows

This is used to control the final number of bolt rows in web side plate, flexible end plate, anglecleat or pinned baseplate connections. The specified number of bolt rows will be used providedthat they physically fit and provided that the resulting number of bolts are adequate for designpurposes. If you set this variable to zero then the number of bolt rows will be determinedautomatically during the design phase.

Bolting procedures

The bolting procedures can be snug, bearing or friction for simple (non-moment resisting)connections, or bearing or friction for moment resisting connections. Snug and bearing boltingprocedures resist the shear load by direct bearing of the bolt on the connected components, whilefriction bolting procedures resist the shear load through friction between the connected surfaces.Bearing and friction bolting procedures require high strength bolts to be fully tensioned.

Wrench type

This simply controls the amount of clearance required around a bolt to allow the tighteningwrench to fit. The wrench type for bolt tightening can be air or hand. It applies to bolted endplate, apex and moment baseplate connections only.

Bolt hole type

The bolt hole type can be standard, oversize (or short slotted), or long slotted. It applies to boltedend plate, apex and moment baseplate connections which use friction bolting procedures only.Standard holes are allowed to have a diameter not exceeding df+2mm when df24mm, ordf+3mm when df>24mm, or df+6mm for baseplates (where df is the bolt diameter). Oversize orshort slotted holes are allowed to have a width not exceeding the greater of 1.25df and df+8mmand a length not exceeding the greater of 1.33df and df+10mm. Long slotted holes are allowed tohave a width not exceeding the greater of 1.25df and df+8mm and a length not exceeding 2.5df.

Weld categories

The weld categories for the main connection components and stiffener plates can be GP (generalpurpose) or SP (structural purpose). SP welds are stronger than GP welds. It is common to use SPwelds for the main connection components and GP welds for stiffener plates.

Flange weld type

This is used to specify fillet welds or butt welds for the ends of the supported member flanges inbolted end plate, welded moment, apex or moment baseplate connections. It is common to usebutt welds in this situation, particularly when the supported member flanges are thick.

Member alignment

Controls the relative alignment of members coming into a connection. It can be set to top, centreor bottom.

For two supported beams coming into either side of a supporting column, the height of the side Bbeam is adjusted in accordance with the specified member alignment to match the side A beam.


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The member alignment variable has no effect when there is only one beam supported by acolumn.

Member alignment variations

Where one or two supported beams connect to the sides of a supporting beam web, the height ofthe supported beams is adjusted in accordance with the specified member alignment to match thesupporting beam flanges.

Threads in shear plane

Affects the bolt shear strength. Bolts designed with the thread in the shear plane have a reducedcross-section and thus, a reduced strength.

Bolts above top flange

This allows you to specify a top flange plate instead of having bolts above the top flange in boltedend plate connections. Otherwise SPACE GASS always places two bolts in the tension flange(s).


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Getting started

This chapter explains how to start SPACE GASS and takes you on a guided tour of the mainSPACE GASS window and all of its menus. It also explains how you should interact withSPACE GASS and respond to its requests for data.


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Starting SPACE GASS

Before proceeding with this section you should have copied and installed SPACE GASS (see alsoInstalling SPACE GASS).

In order to start SPACE GASS, you can either:

1. Double-click on the "SPACE GASS" shortcut on your desktop.

2. Double click on a SPACE GASS data file (they end with .SG).

If you are running SPACE GASS for the first time, you will be taken through part of the SPACEGASS configuration program (see also Configuring SPACE GASS).


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The main SPACE GASS window

When you start SPACE GASS, the following main window appears with the structural model forthe current job displayed in it.

The title bar

This is the colored band across the top of the window, it contains the SPACE GASS version, thename of the current job and the scale of the viewport if it is being displayed in full-screen mode.

The menu bar

The second band across the top of the window contains the twelve main menu items. By selectingone of the main menu items you can gain access to all of the options contained within that menu.The menu bar allows you to access all of the programs features (see also The menu system).

The toolbars

The buttons across the top and to the left of the display area form the toolbars. The toolbarbuttons replicate the most commonly used menu items and give you instant access to them (seealso The toolbars). The graphics settings buttons across the bottom of the screen display thecurrent settings for the drawing tool and allow the settings to be toggled.


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The graphics display area

The area in the centre of the main window displays the structural model for the current job. Theglobal axes are also shown in the top-right corner. You can display up to four viewports in thisarea.

The text display area

The area below the graphics settings buttons forms the text display area. The first line displaysthe project heading, job heading and the local axis settings. The second line is a multi-purposeline which usually contains the status line, but which also periodically displays other prompts andmessages, some of which are purely informative and some of which require you to respond.


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Using the mouse

This section gives basic information about using the mouse. If your mouse has more than onebutton, use the left button unless specifically told otherwise.

The right mouse button is generally used by SPACE GASS to replicate the keyboard ESC key.The ESC key generally enables you to abort from the current operation or dialogue box. Note,however that the right mouse button is not always active, such as when a dialogue box is open.

The following definitions explain the basic terms that are associated with using the mouse.

Pointer

The descriptive cursor that appears on the screen and tracks the mouse movement.

Point

Position the pointer on an item.

Click (or Pick)

Point to an item, and then quickly press and release the left mouse button.

Right Click

Point to an item, and then quickly press and release the right mouse button.

Double-click

Point to an item, and then quickly press and release the left mouse button twice.

Drag

Point to an item, press and hold the left mouse button as you move the mouse to a new location,then release it.


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Dialogue boxes

When you choose a command, a dialogue box often appears so that you can select options or typein data. If an option is dimmed, it is not currently available.

Using the keyboard with a dialogue box

Although its usually easiest to use a mouse while you work in a dialogue box, you can also selectoptions or fill in information with the keyboard. Some of the standard keyboard operations thatyou can use in dialogue boxes are as follows.

TAB Move to the next field in the dialogue box.

SHIFT+TAB Move to the previous field in the dialogue box.

ENTER Equivalent to selecting the Ok button.

ESC Equivalent to selecting the Cancel button.

ALT If an option, box or button has an underlined letter in itsname, you can choose that item by holding down ALTwhile typing the underlined letter.

Moving a dialogue box

You can move a dialogue box dragging its title bar to the new location. The title bar is the coloredband along the top of the dialogue box.


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Closing a dialogue box

You can close a dialogue by pressing the Ok or Cancel buttons. Alternatively, if the dialogue hasa control-menu box at the left side of the title bar, you can double-click on it to replicate thecancel button. If you single click on the control-menu box, a control menu appears which alsoallows you to close or move the dialogue.


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Data entry

Dialogue boxes can contain a wide variety of data entry fields, boxes, options and buttons. Someof the commonly used ones in SPACE GASS are:

Command buttons

You choose a command button to initiate an action, such as carrying out or cancelling acommand. The Ok, Cancel and Help buttons are common command buttons. In SPACE GASS,they are usually located in the top-right corner of the dialogue box. To choose a command button,you can either click on it or press TAB until the button you want is selected, and then pressENTER.

Scroll bars

Some windows and dialogue boxes have scroll bars which you can use to view information thatdoes not fit inside the window. If you can view all of the contents of a window or dialogue boxwithout having to scroll, the scroll bars may be absent or dimmed to indicate that they cannot beused.

Scroll bars have a scroll arrow at each end with a moveable scroll box in between. To scrollthrough information displayed in a window or dialogue box, drag the scroll box to the desiredposition. To scroll one line at a time, click on the scroll arrows, or to scroll continuously, hold ascroll arrow down. To scroll one page at a time, click on the scroll bar on either side of the scrollbox.

Text boxes

You can type appropriate information directly into text boxes. Text boxes are generally sidewaysscrollable so that they can hold more data than can be displayed in the box.

Sometimes numeric text boxes have arrow buttons attached to them. These are called "spinbuttons" and you can change the number in the text box, without actually having to type anything,by clicking on the arrows or holding them down.

When entering data into a text box, you will find that quite often a default value is alreadydisplayed there. If a default value is highlighted then as soon as you start typing it will be erased.To edit a default value without causing it to be erased, you can simply click somewhere in the


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text box or press one of the keyboard ARROW keys before you begin typing. The point whereyou clicked becomes the insertion point for the new text.

If you want to highlight text in a text box, you can simply drag the pointer across the text, ordouble-click on a word to select one word at a time. Any text that you type will then replace thehighlighted text. You can also delete highlighted text by pressing "DEL" or "BACKSPACE".

Generally, when you select a text box by clicking on it, its default value does not becomehighlighted, however if you use the TAB key to get to the text box, its default value does becomehighlighted.

List boxes

Display a list of items in a scrollable window from which you can make a selection. In specialcircumstances, you can sometimes select more than one item from a list box.

Combo boxes

Appear initially as a rectangular box containing the current selection. When you select the downarrow in the square box at the right of the selection, a list of available choices appears. If there aremore items than can fit in the box, scroll bars are provided.

Radio buttons

Represent a group of mutually exclusive options. You can select only one option at a time. If youalready have one option selected, your current selection replaces it. The selected radio buttoncontains a black dot.

Check boxes

Represent non-exclusive options. You can select as many check box options as needed. When acheck box is selected, it contains an X.


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Lists

Sometimes SPACE GASS will ask you to provide a list of items such as nodes, members or loadcases. Lists can be typed in as integers separated by commas or dashes. If, for example, your listwas to contain the items 1,2,6,7,8,9,13,14,15 and 20, you could type it in as1,2,6,7,8,9,13,14,15,20 or as 1,2,6-9,13-15,20. Dashes simply allow you to list a range ofnumbers.

A special type of list is used to input flange restraint positions in the steel member designmodules. This list accepts @s (AT symbol) instead of dashes and can be used to quickly input anumber of equally spaced flange restraints. For example, a list containing the following numbers1.2,2.4,3.6,4.8,6.0,6.6,7.2,7.8,8.4 could be replaced with [email protected],[email protected].

When using a file selection dialogue box in which you have toscroll to get to the file you want, you can simply type in the first couple of characters of the filename to automatically scroll it into view.


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Managing job files

Whenever you run SPACE GASS, it loads and displays the job that you previously had open. Theprocedures for starting new jobs, opening previously saved jobs, saving jobs, deleting jobs andcleaning up jobs are explained in the following sections.


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Starting a new job

Click on the "New Job" toolbar button or select "New" from the File menu.

Opens a new job. If you have unsaved changes to the current job file then SPACE GASS will askyou is you wish to save these changes.


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Opening a job

Click on the "Open Job" toolbar button or select "Open" from the File menu.

Opens a previously saved job. You will be prompted for the name of the file you wish to open.SPACE GASS, by default, looks in the most recently accessed folder when opening a job.


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Saving a job

Click on the "Save Job" toolbar button or select "Save" from the File menu.

Saves all changes made to the job. If you have not already created a name for the job (ie. if it ispreviously unsaved) then you will be prompted for a file name and a location (performs the samefunction as selecting "save as" from the file menu).

"Save As" is similar to "Save", except that the job is saved under a new name that you specify.For example, if you open Job1, make changes to it and then use Save As to save it as Job2, Job1will be left unchanged while Job2 will be the changed version of Job1.


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Deleting a job

Click on "Delete Job" from the File menu.

Deletes the entire job. Use it with care because the job cannot be recovered after it has beendeleted.


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Cleaning up a job

Click on the "Clean-up Job" toolbar button or select "Clean-up Job" from the File menu or thefloating menu.

Cleans up your model by deleting obsolete items or items that are no longer connected toanything. For example, it will remove loads that are applied to non-existent nodes or members, orsection properties that are not being used by any members. It is very useful for quickly removingthe causes of many analysis errors.

The clean-up feature can also merge nodes that are within a specified distance of one another,transferring members, restraints, loads, etc. from the deleted nodes to the retained nodes. If thisaction results in a change to the way the structure responds to the applied loads then an errormessage will be displayed and the clean-up will not proceed. Any pairs of nodes close togetherthat are linked with master-slave constraints will not be merged.

Dummy nodes can be removed provided they are not used as direction nodes for members.


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Job status

Select "Job Status" from the File menu.

Displays the current status of the job as shown below.


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The status line

The status line appears in the second line of the text display area of the main SPACE GASSwindow. It indicates which data is present for the various parts of the current job.

The presence (or absence) of data is indicated by sequences of characters shown as follows. In allcases, unless otherwise indicated, "Y" represents "data exists", while "N" represents "no dataexists".

If, for example, you have performed a static analysis, a dynamic frequency analysis and an elasticbuckling analysis (but no dynamic response analysis), the "Analysis" part of the status line wouldappear as "Analysis:YYNY".

You can use the status line as a check to ensure you have entered sufficient data beforeperforming another operation. For instance, you cannot perform a static analysis until you haveapplied some type of load to the structure (in addition to which, sufficient data must be present onthe structure itself). Check for the appropriate code in the status line window before proceedingwith the operation.

Headings

1. Project name, Job name, Designers initials and Notes

(Y/N)

Structure

1. Nodes

2. Members

3. Restraints

4. Sections

5. Materials

6. Master-slave constraints

7. Member offsets

(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)

Loads

1. Node loads

2. Prescribed node displacements


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3. Member concentrated loads

4. Member distributed forces

5. Member distributed torsions

6. Thermal/prestress loads

7. Self weight

8. Combination load cases

9. Load case titles

10. Lumped masses

11. Spectral load data

(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)

Analysis

1. Static analysis, where"N"=not analysed,"Y"=analysed,"U"=desired convergence not obtained,"I"=ill-conditioned

2. Dynamic frequency analysis, where"N"=not analysed,"Y"=analysed

3. Dynamic response spectrum analysis, where"N"=not analysed,"Y"=analysed

4. Buckling analysis, where"N"=not analysed,"Y"=analysed

(Y/N/U/I)(Y/N)(Y/N)(Y/N)

Steel

1. Steel member design data

2. Steel Member design/check results, where"N"=not designed or checked,"D"=designed,"C"=checked

3. Connection design data

4. Connection design results, where"N"=not designed,"D"=designed

(Y/N)(D/C/N)(Y/N)(D/N)

Concrete

1. Concrete column design data


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2. Concrete beam design data

(Y/N)(Y/N)


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The menu system

The menu bar appears immediately below the title bar in the main SPACE GASS window.

To open a menu, click on it with the mouse, or press ALT and then use the ARROW keys tomove across to the desired menu, and then press ENTER. Alternatively, you could hold down theALT key while typing the underlined letter in the menu name.

To choose an item from a menu, click on the item with the mouse or drag the selection cursordown the menu until the desired item is highlighted, and then release the mouse button.Alternatively, you could use the ARROW keys to move down the menu to the desired item, andthen press ENTER.

Many of the menu items can also be accessed using a keyboard shortcut. They are shown in themenus with CTRL+K or SHIFT+CTRL+K after them, where K represents the shortcut key. Forexample, to operate the Edit Libraries shortcut of CTRL+L, you must hold down the CTRL keyand then hit the L key. Alternatively, to operate the Renumber shortcut of SHIFT+CTRL+R, youmust hold down the SHIFT and CTRL keys together and then hit the R key.

Each of the menus in the menu bar is explained briefly as follows.


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The file menu

This menu controls most of the programs job and file operations, including exiting from SPACEGASS.

The file menu lets you create a new job, open an existing job, save the current job under its ownname or under a different name, display a job status window, delete a job, etc.

It also allows you to start the text editor or calculator linked into SPACE GASS. The default texteditor and calculator are the standard Windows ones, however you can link in any other Windowscompatible text editor or calculator by choosing "Folders and Files" from the Config menu.

SPACE GASS is able to import and export data files in standard ASCII text format, DXFdrawing format, SDNF steel detailing format, Microstran ARC format, ZIP archive format,Microsoft Access format, Microsoft Excel format and Microsoft Word format. The File menugives you access to all of these facilities as well as the ability to import or export backup copiesof jobs in their native SPACE GASS format.


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The File menu also gives access to the library editor which allows you to edit any of the standardsection, material, bolt, plate, weld, reinforcing bar and spectral curve libraries supplied withSPACE GASS. You can also use the library editor to create your own custom libraries.

The Copy to Clipboard item allows you to copy the current graphics display area into theWindows clipboard, ready for pasting into other Windows programs.

You can exit from SPACE GASS by choosing "Exit" from the File menu, and you can open oneof the four most recently used jobs by choosing one of the numbered items (with job path) fromthe bottom of the File menu.


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The structure menu

This menu lets you input and edit the models structural geometry.

The Structure menu allows you to change the units system for the current job and input theproject and job headings.

The structure wizard offers a very fast method of inputting a structure provided that it conformsloosely to one of the standard structures included in SPACE GASS.

Each of the "Nodes", "Members", "Node restraints", "Section properties", "Material properties","Master-slave constraints" and "Member offsets" items in the Structure menu have twoalternative methods of input.


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If you choose a datasheet item, a display window appears with the data layed out in rows andcolumns, much like a spreadsheet.

If you choose a graphical item, SPACE GASS allows you to operate directly on the graphicsdisplay area. You can draw new members, change their attributes, or highlight nodes or membersand then change their restraints, properties or constraints.

The remainder of the items in the Structure menu are purely graphical. They offer variousgraphical means of inputting and manipulating the structural geometry to suit your exactrequirements.


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The loads menu

This menu lets you input and edit loads on the structure.

Like the Structure menu, the Loads menu offers datasheet and graphical alternatives for most ofits items.

The datasheet items operate in similar fashion to the Structure datasheet items, while thegraphical items allow you to highlight nodes or members graphically and then input or edit loadsfor them.


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The analysis menu

This menu gives you access to the five types of structural analysis available in SPACE GASS.

The order of the Analysis menu suggests the order in which you will most probably perform thevarious types of analysis. For instance, you must perform a static analysis and save the stiffnessmatrix to disk before you can perform a dynamic frequency analysis. Furthermore, beforedetermining the dynamic response of a structure you must have performed a dynamic frequencyanalysis.


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The design menu

This menu allows you to perform steel or concrete designs and checks.

For a steel member design/check, the items in the Design menu allow you to input/edit the designdata with a datasheet or graphically, and then perform a design or check to one of the listed steelstructures codes. After a steel member design you can then use the "Update frame member sizes"item to transfer the new designed member sizes into the analysis model.

For a steel connection design, the Design menu has items for datasheet or graphical input of thedesign data. You can then perform a connection design.

The "Concrete Column Design" and "Concrete Beam Design" items allow you to design or checkreinforced concrete columns and beams. You can graphically select the desired member(s) andthen open the concrete design dialogue to perform the design or check phase.


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The output menu

This menu gives you access to the programs output report and graphics hardcopy facilities.

The frame analysis and steel design text reports can be previewed on the screen or directedstraight to the printer or to a file.

The "Graphics hardcopy" item sends a copy of the graphics display area to the printer or to a file.

To output concrete column design data and reports you must first enter the concretedesign module and then click on its "Print" toolbar button.


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The view menu

This menu controls the graphics display area and allows you to select the content and format ofwhat is displayed there.

Most of the items in this menu are viewport specific. That is, you can have different settings anditems activated for each viewport. You can tell if a toggle item has been selected as there will be atick beside it. Greyed-out items indicate that the command is inappropriate to the specificcircumstance, or there is not enough data (eg. if you have not done a static analysis you cannotdisplay a bending moment diagram).


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The query menu

This menu allows you to query the frame and its superimposed diagrams.

Selecting "Frame" allows you to click on any node or member to obtain a dialogue full ofinformation about its geometry and attributes, including the material and section properties.

Selecting "Analysis Results" is similar to "Frame" except that you can obtain a tabulated displayof analysis results for any node or member that you click on.

The remaining menu items allow you to move a crosshair along any member and obtain a readoutof the diagram values at the crosshair point (ie. the "Station") on the member.


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The settings menu

This menu controls various settings that affect how the graphics functions operate.

The first seven items in this menu are specific to each viewport, allowing you to specifydifferent settings for each.

The "Grid" and "Snap" items control a rectangular grid of dots which provide a visual aid and apositioning aid when you are locating points in the graphics display area. The "Ortho" and"Attach" items are also positioning aids which let you draw truly horizontal, vertical lines andinclined lines, and attach lines and points to nodes and members.

The "Operating plane" item can be used to set any of the three global planes as the working plane,while the "Coordinates display" tells you the location of the mouse pointer and lets you switchbetween Cartesian/polar and absolute/relative coordinate systems.

The first six items of the settings menu can also be changed using the graphics settings buttonslocated at the bottom of the screen. You can also toggle these settings using the keyboard, duringgraphics operations, making it very easy to change settings while you are editing a job. Thekeyboard keys that correspond with each command are as follows:

G - Grid

S - Snap

O - Ortho Mode

A - Attach

P - Operating Plane

C - Coordinates Display


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The aperture circle and crosshair are special graphics cursors which appear when attachment tonodes or members is possible, or when the graphics cursor is not at the same point as the mousepointer (such as when snap or ortho modes are on). Their sizes can be modified from the Settingsmenu.

All curved lines in SPACE GASS actually consist of a series of short straight lines. Thenumber of straight line segments used to approximate a curve can be controlled by the "Curvedline resolution" item.

The "Bending moment diagram sign" item lets you specify whether bending moments should bedrawn on the tension side or the compression side of members.

The last item in the Settings menu allows you to shade loading, moment, shear force and axialforce diagrams.


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The config menu

This menu allows you to configure SPACE GASS to suit your exact requirements.

For a full explanation of the Config menu items, see also Configuring SPACE GASS.


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The window menu

This menu controls the display and configuration of multiple viewports.

This menu has items that are typical to most Windows programs with multiple viewports.

Only one viewport is opened by default, however you can use this menu to open up to fourviewports. Once you have opened a viewport it can be arranged using one or more of the items inthis menu.

The "Viewports" item allows you to select from a variety of pre-defined arrangements for youropen viewports (in addition to opening additional viewports). This item also has an option thatallows you to enable or disable active viewports under the cursor. If activated then any viewportthat is under the cursor when you have selected a graphics command (among others) will becomeactive.


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The help menu

This menu gives you access to the on-line SPACE GASS reference manual.

The "Contents" item allows access to the manual via a table of contents, while the "Search forhelp on..." item allows access via an index.

The other items provide useful information about using the help facilities, about SPACE GASSand also information about your system.


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The toolbars

The toolbars consist of buttons that provide quick and easy access to commonly used features.When you point to a toolbar button, SPACE GASS displays its name in a yellow tooltip. Each ofthe toolbars is explained in the following sections.


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The left side toolbar

This toolbar controls most of the graphics display options that can be toggled on or off.


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The top toolbar

This toolbar controls a mixture of file, editing, viewing and settings options.


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Modelling the structure

Before a frame can be modelled and analysed with a program such as SPACE GASS, it must firstbe idealised and modelled mathematically. The most popular mathematical model uses theconcept of nodes connected by elements of a finite size (finite elements).

SPACE GASS requires that frames are represented by nodes connected by members. Such nodesare generally free to move and rotate in space. Practical structures, however are connected to afooting in some way, and so node restraints must be applied which limit the movement ofselected nodes.

The relative movement between two nodes connected by a member is a function of the sectionand material properties of that member. Loads can be mathematically represented in the modeland can be applied to nodes and members. Such loads include all of the normal force and momenttype loads, in addition to load inducers such as prescribed displacements and temperaturedifferentials. A single analysis can consider numerous load cases, each of which may containmany different load types.

During the analysis phase all unrestrained node displacements (degrees of freedom) are calculatedfor each load case. Member forces and moments are then determined from the relative movementof each end of the member and, finally, reactions are calculated by equating member endreactions at each restrained node.

If the analysis selected is non-linear, SPACE GASS does an initial linear analysis and thenmodifies the stiffness matrix for each member based on the previous analysis node displacementsand member axial forces. It then re-analyses the structure for the modified member stiffness andcontinues iterating the analysis phase in this way until convergence is achieved.


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Coordinate systems

The shape and position of a structure in space is defined by a set of global axes (X,Y,Z). All nodecoordinates, for example, are input relative to the global axes system. The global XZ plane isassumed to be horizontal, while the global Y-axis points vertically upwards.

Each member also has its own set of local axes (x,y,z). This is necessary because sectionproperties, member loads, forces and moments are most conveniently referenced by axes alongand at right angles to the member. All axes are right hand orthogonal. This means that if you arelooking at the XY plane with the Y-axis pointing upwards and the X-axis pointing to the right, theZ-axis points towards you shown as follows.

X

Y

Z

xy

z

A

B

Local and global coordinates


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End B

yy`

z

z`

aa Direction anglea =

Local coordinates and the direction angle

In order to determine the orientation of the local axes for a member, you should first assume azero direction (skew) angle with no direction node or direction axis and apply rules 1-3. If thedirection angle is not zero or if a direction node or direction axis is defined for the member, youshould then rotate the local axes about the longitudinal axis of the member according to rule 4.

1. The local x-axis lies along the axis of the member and points from node A to node B.

2. The local y-axis lies at right angles to the local x-axis and points in the same generaldirection as the global Y-axis. It is orientated such that the local xy-plane is parallel to theglobal Y-axis.

3. For members that have their longitudinal axis parallel to the global Y-axis, rule 2 above isundefined. Consequently, for these members, the local z-axis points in the same direction asthe global Z-axis.

4. If the direction angle is not zero, rules 2 and 3 above are modified so that the member(together with its local axes) is rolled about its own axis an amount equal to the directionangle. If you are looking along the member from node B to node A, a positive directionangle causes an anti-clockwise roll.

Alternatively, if a direction node or direction axis has been defined for the member, themember (together with its local axes) is rolled about its own axis until the members localxy-plane lines up with the direction node or direction axis.

If you are unsure of the orientation of the local axes for a particular member, you can displaythem graphically (see also View node and member properties).


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Sign conventions

Items which act along or about an axis are considered to be positive when they act along or aboutthe positive axis direction. Positive rotations conform to the right hand screw rule shown asfollows.

Right hand screw rule

Applied loads have their sign determined by the axes system in which they are referred. Mosttypes of member loads can be specified in either the global or local system, however node loadsand self weight must be referenced by the global system.

Node displacements are positive if they displace along or around the positive global axisdirections. External reactions are positive if they act along or around the positive global axisdirections.

Member forces and moments follow the sign conventions as follows.


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Member forces and moments

Positive axial forces cause compression in the member.

Positive moments cause compression on the positive axis side of the member.

Channel and angle sections have their flange toes pointing in the direction of the local z-axis. Positive y-axis moments therefore cause the flange toes to go into compression.

Positive shears cause the node A end of the member to translate in the direction of the positiveaxis with respect to the node B end.


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Positive torsions cause the node A end of the member to rotate anti-clockwise with respect to thenode B end when observed from the node B end.


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Symmetrical structures

In many situations, where frames are symmetrical about one or more arbitrary lines or points, it ispossible to save a considerable amount of analysis time and effort by reducing the size of theframe. For example a rectangular grid with four identical quadrants could be analysed by usingjust one quadrant. The quadrant boundaries which were normally connected to adjacent quadrantswould have boundary conditions applied in the form of node restraints. These restraints wouldsimulate the effect of adjacent quadrants.

The principle can be easily demonstrated by considering the three span continuous beam shownas follows which lies in the XY plane. It is simply supported at four points and is loaded with auniformly distributed load. Because the beam is symmetrical about its centre, it could be cut inhalf and analysed as a two span beam.

Equivalent beams

Intuitively, the rotation at the centre of the beam is zero. Thus it can be seen that even thoughthere may be vertical deflection at the beam centre, the only effect that the right hand half of thebeam has on the left half is to prevent rotation at the centre. This effect could be simulated byreplacing the right hand half of the beam with a rotation restraint as shown in the diagram above.

! IMPORTANT NOTE !

Symmetrical frames cannot be easily simplified unless they also have symmetrical section andmaterial properties and symmetrical loading conditions. For example, if the beam in the aboveexample was only loaded over the first three spans, then the rotation at the central support wouldnot be zero and therefore could not be restrained to zero


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Ill-conditioning and instabilities

The most common analysis errors are caused by structures which are not correctly conditioned orstabilised.

Ill-conditioning commonly occurs when frames contain members of widely varying stiffnesss.When a very stiff member is connected to a very flexible member and their stiffness matrices areassembled into the structure stiffness matrix, some of the stiffness terms of the flexible membercan be completely lost due to their insignificance in comparison with the stiffness terms of thestiff member. Hence, the flexible member is not completely represented and ill-conditioningoccurs.

SPACE GASS contains an algorithm which checks for possible ill-conditioning and displayswarning messages if appropriate. Generally, these messages appear well before ill-conditioningactually occurs. They do, however serve to highlight structures which are close to being ill-conditioned. If after the analysis, the sum of the reactions equals the sum of the applied loads thenit can be assumed that the frame is well conditioned.

Instabilities occur when one or more nodes are free to translate or rotate without resistance fromthe frame. Sometimes unstable structures are very easy to detect, such as when restraints have notbeen applied or when an obvious collapse mechanism is possible.

Instabilities are often very subtle and difficult to isolate. For example, if an unrestrained node hasa pinned connection to each of its connecting members then it would be free to rotate and aninstability would result. This type of instability can be hard to detect because it only affects onenode in the structure. True trusses must therefore have every rotational degree of freedomrestrained.

Sometimes highly ill-conditioned frames can also be interpretedas being unstable by the program.

Another common type of in

SGWIN

Documents

member data

node data

headings text

nodes text

node loads text

members text

text formatting

member offset text