Analysis gtstrudl

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(1)GT STRUDL. ®. Integrated CAE System for Structural Engineering Analysis and Design The information found in this User Guide represents a subset of the Analysis features of GTSTRUDL. For a more detailed description of any GTSTRUDL feature, please refer to the GTSTRUDL User Reference Manuals that are installed with GTSTRUDL software in PDF format. To purchase a printed version of any GTSTRUDL user document, please contact your software distributor for details.. Analysis GT STRUDL User Guide. Revision 6, April 2009 Computer Aided Structural Engineering Center School of Civil and Environmental Engineering Georgia Institute of Technology Atlanta, Georgia 30332-0355 U.S.A. Telephone: +1-404-8942260 FAX: +1-404-8948014 E-Mail: [email protected].

(2) GTSTRUDL User Guide: Analysis. Revision History Revision No. First Edition. 1. Date Released 4/97. 6/99. Description First Edition describing general structural modeling concepts, global and local reference frames, input/output, automatic mesh generation, graphical display, data base management, static frame and finite element analysis, and introduction to dynamic analysis. Complete rewrite for GTSTRUDL 9901 for use under Windows NT/95/98. In addition, the chapter on Dynamic Analysis Commands is expanded to include a description of the more frequently used commands to perform dynamic analysis, output dynamic analysis results, and combine dynamic analysis results with static analysis results.. 2. 2/02. Relevant updates describing new features in GTSTRUDL Versions 25 and 26, and various typographical error corrections.. 3. 6/03. Relevant updates describing new features in GTSTRUDL Version 27, and various typographical error corrections.. 4. 1/05. Relevant updates describing new features in GTSTRUDL Version 28, and various typographical error corrections.. 5. 12/06. Relevant updates describing new features in GTSTRUDL Version 29, and various typographical error corrections.. 6. 4/09. Relevant updates describing new features in GTSTRUDL Version 30, and various typographical error corrections.. - ii -.

(3) Notices This GTSTRUDL® User Guide: Analysis, Revision 6, is applicable to: ®. GTSTRUDL® Version 30 and higher numbered versions for use on PC’s under the Windows Vista/XP/2000/NT operating systems. The GTSTRUDL computer program is proprietary to, and a trade secret of, the Georgia Tech Research Corporation, Atlanta, Georgia, U.S.A.. Disclaimer The Georgia Tech Research Corporation (GTRC) and the Georgia Institute of Technology make no representation or warranty expressed or implied as to the adequacy of this documentation or the software described herein. In no event shall the Georgia Tech Research Corporation, or the Georgia Institute of Technology, their employees, their contractors, or the authors of this documentation be liable for special, direct, indirect, or consequential damages, losses, costs, charges, claims, demands, or claim for lost profits, fees, or expenses of any nature or kind.. Restricted Rights Legend Any use, duplication, or disclosure of this software by or for the United States Government shall be restricted to the terms of a license agreement in accordance with the clause at DFARS 227.7202-3 (June 2005). This material may be reproduced by or for the United States Government pursuant to the copyright license under the clause at DFARS 252.227-7013, September 1989. Copyright © 1997 to 2009 by Georgia Tech Research Corporation Atlanta, Georgia 30332-0355 U.S.A. All Rights Reserved Printed in United States of America. GTSTRUDL® is a registered service mark of the Georgia Tech Research Corporation, Atlanta, Georgia, U.S.A. ® ® ® ® Windows Vista , Windows XP , Windows 2000 , and Windows NT are registered trademarks of Microsoft Corporation in the United States and/or other countries.. - iii -.

(4) Forward The development of GTSTRUDL began in September 1975 by the School of Civil Engineering, Georgia Institute of Technology, Atlanta, Georgia U.S.A. Since then, over 390 manyears have been invested in the continuous research, development, maintenance, validation, education, and technical support activities in connection with GTSTRUDL. Today, GTSTRUDL is fully supported by the Computer Aided Structural Engineering Center ("CASE Center"), School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia U.S.A., and is licensed worldwide through the Georgia Tech Research Corporation. The CASE Center is committed to continually improving its position of leadership in the research and development of structural engineering analysis and design software, and to serving as a technological pipeline through which results of research and development flow from Georgia Tech to industry, government, and educational institutions in a form which sets the highest standards of quality, performance, and value.. - iv -.

(5) Table of Contents CHAPTER. PAGE. Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DISCLAIMER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Restricted Rights Legend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Forward . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1.. 2.. 3.. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1- 1. Commands and the Graphical User Interface . . . . . . . . . . . . . . . . . . . . . . . . . . Format of the Descriptions of Commands in This Guide . . . . . . . . . . . . . . . . . . Subset of GTSTRUDL Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1- 1 1- 4 1- 5. CHARACTERISTICS OF THE STRUCTURAL ANALYTICAL MODEL . . . . . . .. 2- 1. Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Member and Finite Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . External World . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Structure Support Boundary Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Member and Finite Element Boundary Conditions . . . . . . . . . . . . . . . . . . . . . . . Independent Loading Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dependent Loading Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2222222-. GLOBAL AND LOCAL COORDINATE REFERENCE FRAMES . . . . . . . . . . . .. 3- 1. 3.1 3.2 3.3 3.4. Global Reference Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Local Member Reference Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Orientation of Local Member Reference Frame (The BETA Angle) . . . Local and Planar Finite Element Reference Frames . . . . . . . . . . . . . . 3.4.1 2D Finite Element Local Reference Frame . . . . . . . . . . . . . . . . . 3.4.2 2D Finite Element Planar Reference Frame . . . . . . . . . . . . . . . . Local Joint Reference Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3- 1 3- 4 3- 8 3- 8 3- 9 3- 10 3- 13. GENERAL COMMANDS AND FILE MANAGEMENT . . . . . . . . . . . . . . . . . . . .. 4- 1. 4.1 4.2 4.3 4.4 4.5. 4- 3 4-11 4-12 4-12 4-18. 3.5 4.. ii iii iii iii iv v. "list" Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . STRUDL Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FINISH Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CINPUT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . COUTPUT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. -v-. 1 1 3 6 6 9 9.

(6) 4.6 4.7 4.8 4.9 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4.19 4.20 4.21 4.22 4.23 4.24 4.25. 5.. 4-21 4-23 4-25 4-26 4-30 4-31 4-35 4-36 4-37 4-38 4-39 4-40 4-43 4-46 4-47 4-49 4-52 4-56 4-58 4-60. DATA BASE MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5- 1. 5.1 5.2 5.3. 5- 2 5- 5 5- 8 5- 8 5-11 5-12 5-14 5-17. 5.4 5.5 5.6 6.. FLIST 1 and FLIST 2 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SCAN Error Flag Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BYPASS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UNITS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . QUERY Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DEFINE GROUP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PRINT GROUP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DELETION of GROUPS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . PRINT GENERATE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CONSISTENCY CHECK Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . OPEN USERDATA FILE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . Files Created by GTSTRUDL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The GTSTRUDL Batch Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LARGE PROBLEM Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RUN Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ALIGN Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NOTES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PRINT COMMAND ARCHIVE Command . . . . . . . . . . . . . . . . . . . . . . . . ACTIVE SOLVER Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DEFINE PHYSICAL MEMBER and SMOOTH PHYSICAL MEMBER Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Data Base Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The GTSTRUDL Data Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SAVE, RESTORE, and AUTOMATIC BACKUP Commands . . . . . . . . . 5.3.1 SAVE and RESTORE Commands . . . . . . . . . . . . . . . . . . . . . . . . 5.3.2 AUTOMATIC BACKUP Commands . . . . . . . . . . . . . . . . . . . . . . . ADDITIONS, CHANGES, and DELETIONS Commands . . . . . . . . . . . . ACTIVE and INACTIVE Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . LOAD LIST Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. GEOMETRY AND TOPOLOGY COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12 6.13 6.14 6.15 6.16. 6- 1. JOINT COORDINATES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6- 3 GENERATE n JOINTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12 DELETION of JOINTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-31 TYPE Command for Members and Finite Elements . . . . . . . . . . . . . . . . 6-33 MEMBER and ELEMENT INCIDENCES Command . . . . . . . . . . . . . . . . 6-49 GENERATE m MEMBERS Command . . . . . . . . . . . . . . . . . . . . . . . . . . 6-60 GENERATE m ELEMENTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . 6-69 DELETION of MEMBERS and ELEMENTS Command . . . . . . . . . . . . . 6-80 DEFINE OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-82 DELETE OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-85 PRINT OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-86 MOVE OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-87 COPY OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-91 LOCATE INTERFERENCE JOINTS Command . . . . . . . . . . . . . . . . . . . 6-97 LOCATE DUPLICATE JOINTS Command . . . . . . . . . . . . . . . . . . . . . . . 6-98 LOCATE DUPLICATE MEMBERS Command . . . . . . . . . . . . . . . . . . . 6-100. - vi -.

(7) 7.. 8.. BOUNDARY CONDITION COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7- 1. 7.1. 7.2. 7.3. 7.4. 7.5. 7.6.. 7- 2 7- 3 7- 6 7-17 7-21 7-29. MEMBER, FINITE ELEMENT, AND MATERIAL PROPERTIES, AND MEMBER BETA ANGLE COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.1. 8.2 8.3 8.4 8.5 8.6 8.7 9.. STATUS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DETERMINE PLANAR JOINTS Command . . . . . . . . . . . . . . . . . . . . . JOINT RELEASES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CALCULATE SOIL SPRING VALUES Command . . . . . . . . . . . . . . . . MEMBER RELEASES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MEMBER ECCENTRICITIES Command . . . . . . . . . . . . . . . . . . . . . . . .. MEMBER PROPERTIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.1.1 MEMBER PROPERTIES Command . . . . . . . . . . . . . . . . . . . . . 8.1.2 MEMBER DIMENSIONS Command . . . . . . . . . . . . . . . . . . . . . . ELEMENT PROPERTIES Command . . . . . . . . . . . . . . . . . . . . . . . . . . MATERIAL Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CONSTANTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BETA Angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BETA REFERENCE JOINT Command . . . . . . . . . . . . . . . . . . . . . . . . . . CALCULATE MEMBER ORIENTATION Command . . . . . . . . . . . . . . . .. INDEPENDENT STATIC LOADING CONDITION COMMANDS . . . . . . . . . . . . 9.1 9.2 9.3 9.4. 9.5 9.6 9.7 9.8 9.9 9.10.. 9.11. 9.12. 9.13. 9.14. 9.15.. 8- 1 8- 2 8- 2 8-21 8-25 8-28 8-30 8-34 8-42 8-49 9- 1. Static Loading Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9- 2 Independent Static Loading Conditions . . . . . . . . . . . . . . . . . . . . . . . . 9- 5 LOADING Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9- 7 Computation of Member Dead Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-11 9.4.1.1 SELF WEIGHT LOADING Command . . . . . . . . . . . . . . . . . . . 9-13 9.4.1.2 SELF WEIGHT LOADING RECOMPUTE Command . . . . . . . 9-18 9.4.2 DEAD LOADING Command . . . . . . . . . . . . . . . . . . . . . . . . . . 9-19 JOINT LOADS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-25 JOINT DISPLACEMENTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-32 MEMBER LOADS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-37 MEMBER TEMPERATURE LOAD Command . . . . . . . . . . . . . . . . . . . . 9-49 MEMBER DISTORTIONS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-52 The Moving Load Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-55 9.10.1 MOVING LOAD GENERATOR Command . . . . . . . . . . . . . . . 9-56 9.10.2 SUPERSTRUCTURE Command . . . . . . . . . . . . . . . . . . . . . . 9-57 9.10.3 TRUCK / VEHICLE LOAD Command . . . . . . . . . . . . . . . . . . . 9-62 9.10.4 LANE LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-71 9.10.5 GENERATE LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . 9-77 9.10.6 END LOAD GENERATOR Command . . . . . . . . . . . . . . . . . . 9-79 9.10.7 Moving Load Generator Examples . . . . . . . . . . . . . . . . . . . . . 9-80 ELEMENT LOADS Command for Non-Isoparametric Elements . . . . . . . 9-90 ELEMENT LOADS Command for Isoparametric Elements . . . . . . . . . . . 9-93 JOINT TEMPERATURE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-102 ROTATE LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-105 AREA LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-108. - vii -.

(8) 10.. COMBINATIONS OF INDEPENDENT LOAD COMPONENTS AND STATIC ANALYSIS RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1.. 10.2.. 11.. STATIC ANALYSIS COMMAND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 11.2 11.3. 12.. 13.. 14.. FORM LOADING Command (Combinations of Independent Loading Condition Components) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1.1 FORM LOAD REFORM Command . . . . . . . . . . . . . . . . . . . . 10.1.2 CONVERT LOAD COMBINATIONS TO/FROM FORM LOADS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1.3 FORM NOTIONAL LOAD Command . . . . . . . . . . . . . . . . . . Combinations of Static Analysis Results . . . . . . . . . . . . . . . . . . . . . . 10.2.1. LOADING COMBINATION Command . . . . . . . . . . . . . . . . 10.2.2. CREATE LOADING COMBINATION Command . . . . . . . . . 10.2.3. COMBINE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.4. CREATE AUTOMATIC LOAD COMBINATIONS Command. 10- 1. 10- 2 10- 7 10- 9 10-12 10-15 10-17 10-23 10-29 10-33 11- 1. STIFFNESS ANALYSIS Command . . . . . . . . . . . . . . . . . . . . . . . . . . 11- 2 ACTIVE SOLVER Command and the GT64M/GTSES Solvers . . . . . . 11-11 GT64M and GTSES Stand-Alone Solvers and the ASSEMBLE FOR STATICS and COMPUTE GROSS RESULTS Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-12. ANALYSIS ERRORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12- 1. 12.1. PERFORM NUMERICAL INSTABILITY ANALYSIS Command . . . . .. 12- 2. PRINTED OUTPUT COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 13- 1. 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 13.10 13.11 13.12 13.13. 13- 2 13- 7 13-11 13-35 13-38 13-40 13-41 13-46 13-61 13-72 13-81 13-83 13-85. PRINT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OUTPUT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LIST Joint, Member, and Finite Element Results Command . . . . . . . . LIST MAXIMUM JOINT DISPLACEMENT Command . . . . . . . . . . . . . LIST MAXIMUM REACTION (ENVELOPE) Command . . . . . . . . . . . . . Internal Member Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SECTION Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LIST Internal Member Results Command . . . . . . . . . . . . . . . . . . . . . . . CALCULATE AVERAGE Finite Element Results Command . . . . . . . . LIST SUM FORCES Command (Resultant Section Forces) . . . . . . . . . STEEL TAKE OFF Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LIST CODE CHECK RESULTS Command . . . . . . . . . . . . . . . . . . . . . . CALCULATE PRESSURE Command . . . . . . . . . . . . . . . . . . . . . . . . . .. SCOPE ENVIRONMENT GRAPHICAL DISPLAY COMMANDS . . . . . . . . . . .. - viii -. 14- 1.

(9) 15.. LINEAR DYNAMIC ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15- 1. 15.1 15.2. Summary of Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15- 2 Dynamic Data Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15- 6 15.2.1 INERTIA OF JOINTS Command . . . . . . . . . . . . . . . . . . . . . . 15- 9 15.2.2 MEMBER ADDED INERTIA Command . . . . . . . . . . . . . . . . 15-22 15.2.3 DAMPING RATIO and DAMPING PERCENT Commands . . 15-23 15.2.4 STORE TIME HISTORY Command . . . . . . . . . . . . . . . . . . . 15-26 15.2.5 STORE RESPONSE SPECTRUM Command . . . . . . . . . . . 15-29 15.2.6 CREATE TIME HISTORY Command & Ramp Feature . . . . 15-34 15.2.7 CREATE RESPONSE SPECTRUM Command . . . . . . . . . . 15-40 15.2.8 DELETE TIME HISTORY and DELETE RESPONSE SPECTRUM Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-43 15.2.9 TRANSIENT LOADING with JOINT LOADS Command . . . . 15-44 15.2.10 TRANSIENT LOADING with SUPPORT ACCELERATION Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-48 15.2.11 RESPONSE SPECTRUM LOADING with SUPPORT ACCELERATION Command . . . . . . . . . . . . . . . . . . . . . . . . . 15-50 15.2.12 FORM STATIC EARTHQUAKE LOAD Command Automatic Generation of Static Equivalent Earthquake Loads ( Section 3.3.3.2.C of NEHRP Guidelines for the Seismic Rehabilitation of Buildings - FEMA Publication 273) . . . . . . . . . . . . . . . . . . 15-55 15.2.13 FORM UBC97 LOAD Command - Automatic Generation of Static Seismic Loads According to 1997 UBC . . . . . . . . . . . 15-65 15.2.14 FORM IS1893 STATIC SEISMIC LOAD Command Automatic Generation of Static Earthquake Loads According to the Indian Standard IS 1893 Seismic Code . . . . . . . . . . . 15-73. 15.3. Dynamic Analysis Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-79 15.3.0 15.3.1 15.3.2 15.3.3 15.3.4 15.3.5 15.3.6 15.3.7. ACTIVE SOLVER Command . . . . . . . . . . . . . . . . . . . . . . . . 15-83 EIGEN PARAMETERS Command . . . . . . . . . . . . . . . . . . . . 15-84 DYNAMIC PARAMETERS Command . . . . . . . . . . . . . . . . . 15-90 LIST RAYLEIGH LOADING Command . . . . . . . . . . . . . . . . . 15-94 DYNAMIC ANALYSIS EIGENSOLUTION Command . . . . . . 15-96 LIST DYNAMIC PARTICIPATION FACTORS Command . . . 15-97 INACTIVE / ACTIVE MODES Command . . . . . . . . . . . . . . . 15-98 RESPONSE SPECTRUM ANALYSIS . . . . . . . . . . . . . . . . 15-100 15.3.7.1 PERFORM RESPONSE SPECTRUM ANALYSIS Command . . . . . . . . . . . . . . . . . . . . 15-101 15.3.7.2 LIST RESPONSE SPECTRUM: SPECTRAL ACCELERATIONS, and PARTICIPATION FACTORS Commands (for use in Base Shear calculations) . . . . . . . . 15-103 15.3.7.3 Base Shear Calculations . . . . . . . . . . . . . . . . . . 15-105. - ix -.

(10) 15.3.7.4. 15.3.8 15.3.9 15.3.10. 15.4. 15.5.3 15.5.4 15.5.5 15.5.6 15.5.7. B. 15-120. COMPUTE RESPONSE SPECTRUM Results Command . 15-123 COMPUTE TRANSIENT Results Command . . . . . . . . . . . 15-127 CREATE PSEUDO STATIC LOADING Command . . . . . . . 15-129. PRINT DYNAMIC DATA Command . . . . . . . . . . . . . . . . . . Graphical Display of Dynamic Analysis Loading Data and Dynamic Analysis Results . . . . . . . . . . . . . . . . . . . . . . . . . . Normalization of Eigenvectors Command . . . . . . . . . . . . . . LIST DYNAMIC Eigen Results and Mass Summary Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OUTPUT MODAL CONTRIBUTIONS Command . . . . . . . . LIST RESPONSE SPECTRUM Results Command . . . . . . LIST TRANSIENT Results Command . . . . . . . . . . . . . . . . .. 15-137 15-140 15-144 15-145 15-148 15-149 15-154. Example Sequence of Dynamic Analysis Commands . . . . . . . . . . . . 15-157. APPENDICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. 15-114 15-116 15-118. Dynamic Data and Analysis Results Output Commands . . . . . . . . . . 15-134 15.5.1 15.5.2. 15.6. 15-107 15-111. Dynamic Results Back Substitution Commands . . . . . . . . . . . . . . . . . 15-121 15.4.1 15.4.2 15.4.3. 15.5. Designing Shear Walls Based on a Response Spectrum Earthquake Analysis . . . . . . . . . . . . . 15.3.7.5 FORM MISSING MASS LOAD Command . . . . 15.3.7.6 Extended Example: RESPONSE SPECTRUM ANALYSIS, FORM MISSING MASS LOAD, and Base Shear Computation . . . . . . . . . . . . . . . . . PERFORM TRANSIENT ANALYSIS Command . . . . . . . . . PERFORM PHYSICAL ANALYSIS Command . . . . . . . . . . PERFORM NUMBER OF MODES COMPUTATION Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Appendices-1. Subset of GTSTRUDL Commands Ordered by Functional Area, and Ordered by Processing Requirements in Each Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. A-1. Subset of GTSTRUDL Commands Ordered by Functional Area, and Ordered by Command in Each Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. B-1. INDEX OF COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Index-1 READER COMMENT FORM. -x-.

(11) General. 1.. Introduction. Introduction This GTSTRUDL User Guide: Analysis contains a condensed description of a subset of the following often used features of GTSTRUDL: 1.. Data base management,. 2.. Automatic mesh generation using commands (note that the GTMenu feature of GTSTRUDL provides an interactive, menu driven interface, to create structural models),. 3.. General description of frame and finite element structures,. 4.. Output of general information and analysis results,. 5.. Graphical display,. 6.. Linear static analysis, and. 7.. Dynamic analysis.. The GTSTRUDL User Guide: Analysis is one of sixteen (16) volumes which constitute the full set of user documentation for GTSTRUDL and GTTABLE as described in Section 1.3 of the GTSTRUDL User Guide: Getting Started.. Commands and the Graphical User Interface Figure 1.1 shows an overview of the use of GTSTRUDL including input, output, and interfaces to postprocessing software. The communication interface between the engineer and GTSTRUDL consists of both: 1.. A command driven Problem-Oriented-Language ("POL") of structural engineering vocabulary words and data (GTSTRUDL User Guide: Getting Started, Chapter 4), hereinafter referred to simply as "commands", and. 2.. A menu driven GTMenu Graphical User Interface ("GUI") which provides simple menu picks to create the finite element model of the structure.. 1-1.

(12) Introduction. General. Figure 1.1 Overview of Using GTSTRUDL. 1-2.

(13) General. Introduction. Commands are used in both the interactive and batch modes of execution of GTSTRUDL, while the GUI is only used interactively, as follows: a.. b.. In the interactive mode of execution, GTSTRUDL i.. Processes commands directly typed by the engineer,. ii.. Reads commands in a previously created text file and referenced by the CINPUT command,. iii.. Processes commands created by menu picks, and. iv.. Responds directly to the GTMenu graphical user interface menu picks.. In the batch mode of execution, GTSTRUDL only reads commands that are contained in a previously created text file.. For commands contained in a previously created text file, such text file may be created by the engineer using a text editor, or by GTMenu, or by any preprocessor software such as one written by the engineer and/or a commercially available CAD system. The commands in the text file may then be read by GTSTRUDL by using the CINPUT command (Section 4.4) in either an interactive or batch mode of execution. It should be noted that the ability to process text files of commands is a particularly important feature of GTSTRUDL since such text files represent a detailed and permanent record of the description of the structural model, and since the commands in the text file may be processed in order to directly recreate the structural model. Such use of text files of commands can also significantly reduce the time required to create, analyze, and design new structural models which may be similar to an old model by simply editing and directly processing the text file of commands. The ability to use both command-oriented POL and menu-oriented GTMenu facilities are very powerful features of GTSTRUDL which permit the engineer to achieve maximum flexibility of creating structural models, in addition to realizing substantial productivity and cost savings. GTSTRUDL creates and maintains a data base of structural information during each execution. The user may modify, SAVE, and RESTORE this data base through the use of various commands. This data base contains all information supplied by the user through the use of commands and GUI menu picks. In addition, the data base contains all result information created by GTSTRUDL as a consequence of analysis and design processing.. 1-3.

(14) Introduction. General. Output from GTSTRUDL is completely controlled by the user through appropriate commands and GUI menu picks. Output may be displayed on an interactive graphics screen or placed in a text file for review and subsequent printing. In addition, the user may request GTSTRUDL to translate information (such as problem description information and analysis and design results) in its data base and output such translated information to the DBX (Data Base Exchange) neutral files. The DBX files may subsequently be processed by user developed software and CAD system software.. Format of the Descriptions of Commands in This Guide The following format is used to describe each command in this Guide: 1.. Simple form of a command: The vocabulary words and syntax of the command are described. In most cases, only a simplified subset of the command is shown in this Guide. Refer to the GTSTRUDL User Reference Manual for a complete description of each command.. 2.. Command elements: A very brief description of the elements of the command is provided. Such elements include command options and the meaning of the data provided with the command.. 3.. Example: One or more very simple examples of how the command may be used are shown.. 4.. Explanation: A general description of the purpose of the command, and a detailed description of how the command operates in the ADDITIONS mode, is given.. 5.. CHANGES Mode: A detailed description of how the command operates in the CHANGES mode is given.. 6.. DELETIONS Mode: A detailed description of how the command operates in the DELETIONS mode is given.. 7.. Extended Examples: A more complete example of the use of the command is given.. 1-4.

(15) General. Introduction. Subset of GTSTRUDL Commands Appendices A and B contain a summary of a subset of GTSTRUDL commands that may be used to perform various types of information processing. The GTSTRUDL User Reference Manual (Table 1.2) should be referred to for a complete description of all available commands. The GTSTRUDL User Guide: Getting Started, and the latest GTSTRUDL Release Guide, Volume 2 (GTMenu), should be referred to for example tutorials and explanations of the use of the GTMenu Graphical User Interface features.. 1-5.

(16) Introduction. General. Blank Page. 1-6.

(17) General. 2.. Characteristics of the Structural Analytical Model. Characteristics of the Structural Analytical Model GTSTRUDL generally treats a real-world physical structure as an analytical model consisting of an assemblage of a finite number of discrete elements (members and finite elements) interconnected at a finite number of joints. Elements are connected to joints through element boundary conditions, while joints are, in turn, connected to the external world through structure boundary conditions. This analytical model (i.e., the "Finite Element model") may be subjected to a variety of loading conditions. In order to fully appreciate the significance of the GTSTRUDL commands as they relate to the characteristics of the analytical model treated by GTSTRUDL, the following descriptions are presented.. Joints A joint in GTSTRUDL is an infinitesimally small, perfectly rigid body which can experience up to a maximum number of six displacement degrees-of-freedom (three translational and three rotational) in the general 3D structure. The actual number of relevant degrees-of-freedom of a joint is determined by the types of members and finite elements incident on the joint. For example, if only space truss members are incident on a joint, then there are only three translational displacement degrees-of-freedom for the joint. On the other hand, if a space truss member, space frame member, and plane stress finite element are incident on the same joint, then the element with the highest order of displacement degrees-of-freedom (the space frame member) determines that there are six displacement degrees-of-freedom (three translations and three rotations) for the joint. Member and finite elements are incident on joints where the connection to a joint is determined by the member and finite element boundary conditions. Joints, in turn, are attached to the external world where the type of attachment is determined by structure boundary conditions. Loads may be applied directly to the joints. Figure 2.1(a) shows a simple structure drawn in a conventional way, and Figure 2.2(b) shows the joints heavily accentuated. It is important to visualize all analytical models of structures in the way shown in Figure 2.1(b).. Members and Finite Elements The elements of a structure, which interconnect the structure's joints, fall into three general categories as follows:. 2-1.

(18) Characteristics of the Structural Analytical Model. 1.. General. A member is a one dimensional element whose centroidal axis is incident on only two joints, and which has one dimension (i.e., distance along the centroidal axis of the member) that is large relative to its other two dimensions (i.e., crosssection dimensions). All applied member loads, and resulting member behavior (i.e., deformations and internal member forces), are expressed as functions of one member dimension, the distance along the centroidal axis of the member. The member boundary condition connection to joints is implied by the type of member such as PLANE TRUSS (hinged to joints) or SPACE FRAME (rigidly connected to joints), and may be modified using the MEMBER RELEASES command such as a SPACE FRAME member hinged to a joint. Figure 2.2(a) shows a typical member element, and Figure 2.1 shows member elements numbered 1 to 8. There are six (6) member element types which are plane truss, plane frame, plane grid, space truss, space frame, and curved member.. 2.. Two-Dimensional (2D) Element, commonly referred to as a surface finite element, is an element whose mid-plane surface is incident on three or more joints, and which has two in-plane dimensions that are large relative to its third dimension (i.e., its thickness). All 2D finite element applied loads, and resulting element behavior (i.e., stretching and bending deformations and stress resultants), are expressed as functions of two dimensions in the mid-plane surface. The 2D finite element boundary condition connection to joints is implied by the particular element used and is part of the element's theoretical formulation, and its boundary conditions cannot be further modified. Figure 2.2(b) shows two example 2D finite elements, and Figure 2.1 shows finite elements numbered 9 to 12. The basis of the theoretical formulations of the 2D finite elements available in GTSTRUDL is summarized in Volume 3 of the GTSTRUDL User Reference Manual.. 3.. Three-Dimensional (3D) Element, commonly referred to as a solid finite element, is an element whose edges are defined by six or more nonplanar joints, and which has no one dimension that is large relative to the other two dimensions. All 3D finite element applied loads, and resulting element behavior (i.e., stresses), are expressed as functions of all three element dimensions. The 3D finite element boundary condition connection to joints is implied by the element's theoretical formulation, and cannot be further modified. Figure 2.2(c) shows two example 3D finite elements. The basis of the theoretical formulations of the 3D finite elements available in GTSTRUDL is summarized in Volume 3 of the GTSTRUDL User Reference Manual.. 2-2.

(19) General. Characteristics of the Structural Analytical Model. There are presently six (6) finite element types: plane strain, plane stress, plate bending, plate stretching and bending, tridimensional, and axisymmetric. Among the six (6) finite element types, there are over one-hundred specific finite elements to choose from, including modern elements with isoparametric or hybrid stress formulations. Note that although the finite element formulations insure certain compatibility conditions along common finite element edges, the connectivity of the structure is, nevertheless, through the joints. Except for these finite element edge compatibility conditions, elements do not touch other elements, and element actions are transferred to other elements and the external world through the joints of the structure as shown in Figure 2.1(b).. External World The external world is an infinitely large half-space rigid body to which various structure support joints connect. The external world may influence the displacement boundary condition (e.g., a support settlement) of a support joint (applied as a loading type in GTSTRUDL) in a way specified by the engineer, while the structure, in turn, has no influence whatsoever on the external world. If a condition such as an elastic soil supporting a structure foundation is to be modeled, the soil model becomes part of the structure analytical model, and boundaries of the soil/structure analytical model are connected to joints which, in turn, are connected to the external world. In Figure 2.1(b), support joints 8, 9, 10, and 11 are connected to the external world.. 2-3.

(20) Characteristics of the Structural Analytical Model. General. Figure 2.1 Structure Joints with Members 1 to 8, and 2D Finite Elements 9 to 12. 2-4.

(21) General. Characteristics of the Structural Analytical Model. Figure 2.2 Typical Member and Finite Elements. 2-5.

(22) Characteristics of the Structural Analytical Model. General. Structure Support Boundary Conditions A structure boundary condition refers to the connection condition between a support joint and the external world. Displacement degrees-of-freedom of a support joint, which are involved in the connection condition, are determined by the types of member and finite elements incident on the support joint. All support joint relevant degrees-of-freedom are restrained (rigidly connected to the external world), when a joint is defined as a SUPPORT joint (Section 7.3). For example, the fully supported joints in Figure 2.3(a) have only two translational degreesof-freedom restrained (and consequently only two corresponding translational force reaction components), while the fully supported joints in Figure 2.3(b) have three degrees-of-freedom restrained (two translational displacements and corresponding force reactions, and one rotational displacement and corresponding moment reaction). Note that full support restraint may be modified by using the JOINT RELEASES command as described in Section 7.3.. Member and Finite Element Boundary Conditions An element boundary condition refers to the connection condition between a member's start or end, or finite element corner node, and a structure joint. The fully connected (rigid) condition is dependent on the specific member type, or specific finite element used. For example, a space truss member is pin connected to a joint, where its three global direction translational degrees-of-freedom are rigidly connected to the joint, but where its rotational degrees-of-freedom are not defined for the truss member. For a space frame member, three translational degrees-of-freedom and three rotational degrees-of-freedom are all rigidly connected to the joint. For a plate bending finite element, one translational degree-of-freedom perpendicular to the plate, and two rotational degrees-of-freedom about the axes in the plane of the plate, are rigidly connected to the joint. Sections 7.4 and 7.5 further describes member boundary conditions. Element boundary conditions for finite elements are inherent in the finite element's formulation and may not be modified. However, member boundary conditions may be modified by using the MEMBER RELEASE command as described in Section 7.4. It is of interest to note here the potential misinterpretation of structure/element boundary conditions, and the importance of visualizing structures as shown in Figure 2.3 (C1 to C4). Consider the simple case shown in the plane frame member structure at support joint 3 in Figure 2.3(C1). This joint is shown in Figure 2.3(C1) as a pinned 6 applied to it. In order to be stable, joint, but it also has a concentrated joint moment M 6 whether or not M 6 is zero in magnitude. the joint must provide a path for the moment M,. 2-6.

(23) General. Characteristics of the Structural Analytical Model. It is not clear in Figure 2.3(C1) how stability of the joint is provided. However, Figures 2.3(C2), (C3), and (C4) show three different joint and member boundary condition cases where moment applied to the joint is transferred into the start end of member 2 in (C2), the external world (reaction moment) in (C3), and the start end of member 3 in (C4). Although this is an oversimplified example, it is obviously critical for correct analysis and design which of these three boundary condition cases represents a proper model of the structure's support joint 3.. 2-7.

(24) Characteristics of the Structural Analytical Model. Figure 2.3 Structure and Element Boundary Conditions. 2-8. General.

(25) General. Characteristics of the Structural Analytical Model. Independent Loading Conditions All loads applied to a structure are defined by being specified in one or more independent loading conditions. These independent loading conditions may consist of one or more types of loads such as joint force and displacement loads, member force, temperature, and initial distortion loads, and finite element force and temperature loads. For example, in a typical structural analysis, gravity loads applied to members, finite elements, and joints could be included in one independent loading condition, while wind loads could be included in another independent loading condition. When GTSTRUDL performs analysis, only the independent loading conditions are included in the governing equations to be solved. Analysis results which are generated (joint displacements, support reactions, member end forces, and finite element stresses and/or stress resultants) are then stored in the problem data base and are associated with each independent loading condition name.. Dependent Loading Conditions Dependent loading conditions are loading conditions for which structural analysis results are formed as linear, absolute, or RMS (Root Mean Square) combinations of structural analysis results associated with any number of independent loading conditions and/or other dependent loading conditions. Results for dependent loadings may be generated during a STIFFNESS ANALYSIS, or following a STIFFNESS or any other type of analysis, depending on the GTSTRUDL commands used. Such results are then stored in the problem data base and associated with each dependent loading condition name. Any number of independent and dependent loading conditions may be defined in GTSTRUDL, where complete structural analysis results are stored in the problem data base under each loading condition, and which results may be selectively or completely output for review. In fact, selective results may be output for any one, or any combination of, independent and/or dependent loading conditions. Loading details are described in Chapters 9 and 10.. 2-9.

(26) Characteristics of the Structural Analytical Model. Blank Page. 2 - 10. General.

(27) General. 3.. Global and Local Coordinate Reference Frames. Global and Local Coordinate Reference Frames Coordinate reference frames are required in order to uniquely and precisely describe the geometric position of a structure in space, the direction of applied joint, member and finite element loads, the direction of computed joint displacements, the direction of computed reactions, and the direction of member and finite element forces and stresses. In addition, coordinate reference frames are required to reference other structural information such as member end eccentricities, end joint sizes, and member properties. GTSTRUDL uses right-handed, orthogonal cartesian reference frames as shown in Figure 3.1. In addition, for input of joint coordinates, right-handed cylindrical and spherical coordinate systems may also be used as described in the GTSTRUDL User Reference Manual. Five types of reference frames are used in GTSTRUDL which are the global, local member, local and planar finite element, and local joint reference frames. They are described in the following sections.. 3.1. Global Reference Frame The geometry of a structure, applied joint loads, joint displacements, and support reactions are referenced to the global cartesian reference frame (Figure 3.2). Member and finite element loads and stresses, member eccentricities, and other data may be referenced to either the global or local member and finite element reference frames. The orientation of the global reference frame with respect to the structure's orientation is completely arbitrary and is implied by the engineer through the joint coordinate input. Generally, one or more global axes are selected to be parallel to one or more characteristic directions of the structure. There is one limitation, however, and that is a member defined as a plane truss, plane frame, or plane grid member must lie in a plane parallel to one of the three global planes (i.e., the XY, XZ, or YZ global plane). Also, although not required, it is recommended that the global Y-axis be oriented opposite to the force of gravity (i.e., positive up), for ease of interpretation of the BETA angle (Section 8.5).. 3-1.

(28) Global and Local Coordinate Reference Frames. Figure 3.1 Coordinate Reference Frame - General. 3-2. General.

(29) General. Global and Local Coordinate Reference Frames. u1, u2, u3 =. positive global joint translation displacement components. u4, u5, u6 =. positive global joint rotation displacement components. Fx, Fy, Fz =. positive global joint force components. Mx, My, Mz. =. positive global joint moment components. Figure 3.2 Global Reference Frame. 3-3.

(30) Global and Local Coordinate Reference Frames. 3.2. General. Local Member Reference Frame Each member has a local reference frame associated with it. Member cross-section area properties, member end joint sizes, member end and internal section forces, stresses, and distortions, and other member actions are referenced to the local member reference frame. Applied member loads, member eccentricities, and certain other member data may be referenced to either the global or local member reference frames. As is shown in Figure 3.3, the local x-axis coincides with the centroidal axis of the member, where the local x-axis (centroidal axis) is taken as a straight line which passes through the joints upon which the member is incident (unless member eccentricities are specified (Section 7.5)), and whose positive direction is arbitrarily selected by the engineer as going from the start joint to the end joint as specified by member incidence input (Sections 6.5 and 6.6). It is important to note that the centroid and shear center of the member's cross-section do not have to coincide. The location of the shear center is given with the MEMBER PROPERTIES command (Section 8.1). The local y- and z-axes coincide with the principal axes of the member cross-section as shown in Figure 3.3. Notice that either the local y or the local z-axis can be either the major or minor principal axis, depending only on the relative numerical values of the cross-section moments of inertias IY and IZ input by the MEMBER PROPERTIES command (Section 8.1). However, for TABLE members where the member properties are taken from prestored tables of section properties, the local y and z principal axes are as shown in Figure 3.4 for analysis processing. Additional considerations of member axes for design should be reviewed in the GTSTRUDL User Guide: Design.. 3-4.

(31) General. Global and Local Coordinate Reference Frames. NOTES:. Centroid and shear center do not have to coincide. Member m goes from joint i to joint j. Local x axis is the straight centroidal axis. Local y and z axes are Principal Axes of the member's cross-section.. Figure 3.3 Local Member Reference Frame. 3-5.

(32) Global and Local Coordinate Reference Frames. Figure 3.4. General. Orientation of Local y and z Principal Axes for Analysis as Stored in GTSTRUDL's Steel Section Tables. 3-6.

(33) General. Figure 3.4. Global and Local Coordinate Reference Frames. Orientation of Local y and z Principal Axes for Analysis as Stored in GTSTRUDL's Steel Section Tables (continued). 3-7.

(34) Global and Local Coordinate Reference Frames. 3.3. General. Orientation of Local Member Reference Frame (The BETA Angle) Although the specification of joint coordinates and member incidences are necessary in order to uniquely and precisely describe the position of members of a structure in space, they are not sufficient specifications for the unique description of the orientation of a member's principal axes. In particular, specification of joint coordinates and member incidences describe only the precise position of a member's local x-axis, but do not describe the position of a member's local principal cross-section axes (i.e., the local member y and z axes) as shown in Figure 3.3. Rather, the precise position of a member's local y and z principal axes is defined relative to the global cartesian reference frame by an angle called the BETA angle. As shown in Section 8.4, the BETA angle is measured in the cross-section plane of the member from some initially assumed reference position (i.e., the BETA = 0.0° position). Sections 8.4, 8.5, and 8.6 describe the BETA angle in detail.. 3.4. Local and Planar Finite Element Reference Frames Two-dimensional (planar) finite elements in GTSTRUDL are associated with local, planar, and global reference frames, while three-dimensional (solid) finite elements are associated only with the global reference frame. With the exception of the rigidity matrix property, finite element properties are independent of the local and planar finite element reference frames. However, the rigidity matrix property is always referenced to the planar reference frame for 2D planar finite elements, and referenced to the global reference frame for 3D solid finite elements. Finite element applied loads may be referenced to the local, planar, or global reference frames depending on the element type. Finite element analysis results are output in the planar reference frame for 2D planar finite elements, and in the global reference frame for 3D solid finite elements. Sections 3.4.1 and 3.4.2 provide a short description of the 2D finite element local and planar reference frames.. 3-8.

(35) General. 3.4.1. Global and Local Coordinate Reference Frames. 2D Finite Element Local Reference Frame Each 2D (planar) finite element has a local reference frame (Figure 3.5) with which it is associated and which is defined as follows (where references to the order of the nodes of an element are based on the direction (i.e., clockwise or counterclockwise) in which the element nodes were specified when defining the incidences of the element): 1.. The origin of the local reference frame is at the first node of the element, where the local x- and y-axes lie in the plane of the 2D element, and where the local zaxis is normal to the plane of the 2D element,. 2.. The positive direction of the local x-axis (xL) is from the first node to the second node of the element,. 3.. The positive direction of the local z-axis (zL) is determined by applying the righthand rule to the order in which the element nodes were input, and. 4.. The positive direction of the local y-axis (yL) is determined by applying the righthand rule to the xL and zL axes.. It is important to note the following regarding 2D finite element local reference frames: 1.. The element's local x- and y-axes lie in the plane of the element, and their directions are dependent on the direction of the side of the element which goes from the first to the second node of the element (side 1).. 2.. For all 2D elements that lie in the same plane, the local axes are all parallel to each other and in the same positive directions only if side 1 of all the elements are parallel to each other, and only if the order of input of nodal incidences are the same.. 3.. It is often the case where the geometry of the finite element mesh is such that all 2D elements in the same plane do not have their first sides parallel to each other, resulting in local reference axes not being parallel to each other. In this case, it becomes extremely difficult to specify loadings applied to all elements which lie in the same plane, and to correctly interpret the finite element analysis results such as stresses (since stress results are referred to an element's reference axes). To solve this difficulty, GTSTRUDL provides a planar reference frame for all 2D finite elements which lie in the same plane.. 3-9.

(36) Global and Local Coordinate Reference Frames. 3.4.2. General. 2D Finite Element Planar Reference Frame Each 2D finite element has a planar reference frame (Figure 3.6) with which it is associated and which is defined as follows: 1.. The origin of the planar reference frame is not of interest. Only the positive directions of the planar reference axes are of interest.. 2.. The positive direction of the planar z-axis (zp) is determined by applying the righthand rule to the order (i.e., clockwise or counterclockwise) in which the element nodes were input (i.e., in the same positive direction as the local z-axis (zL)).. 3.. The direction of the planar x-axis (xp) lies along a line which is parallel to the line of intersection of the plane of the element and the Global XY plane. The positive direction of xp is determined as follows:. 4.. a.. If the planar z-axis (zp) does not lie in a plane which is parallel to the Global XZ plane, then the positive direction of the planar x-axis (xp) is such that its projection on the Global X-axis is in the positive direction of the Global X-axis.. b.. If the planar z-axis (zp) does lie in a plane which is parallel to the Global XZ plane, and if zp is parallel to the Global Z-axis, then the positive direction of the planar x-axis (xp) is in the same positive direction as the Global Xaxis. If zp is not parallel to the Global Z-axis, then the positive direction of the planar x-axis (xp) is in the same positive direction as the Global Y-axis.. The positive direction of the planar y-axis (yp) is determined by applying the righthand rule to the xp and zp axes.. 3 - 10.

(37) General. Global and Local Coordinate Reference Frames. ELEMENT INCIDENCES 6 2 7 8 3. ELEMENT INCIDENCES 6 7 2 3 8. Figure 3.5 2D Finite Element Local Reference Frame. 3 - 11.

(38) Global and Local Coordinate Reference Frames. Figure 3.6 2D Finite Element Planar Reference Frame. 3 - 12. General.

(39) General. 3.5. Global and Local Coordinate Reference Frames. Local Joint Reference Frame Each joint in a structure modeled with GTSTRUDL has a local joint reference frame and the global reference frame associated with it (Figures 3.7(a), (b), and (c)). Except for input describing certain structure boundary conditions, all other input joint data, and all output computed joint results, are referred to the global reference frame. The only time the local joint reference frame is not parallel and in the same positive direction as the global reference frame is at a support joint where the displacement restraints and releases are not parallel to the global reference frame axes. In this case, the local reference frame is oriented parallel to the restraint and released directions. The orientation of a non-parallel local joint reference frame is given by the JOINT RELEASES command (Section 7.3). Figure 3.7(d) shows a structure where only one support joint (joint 4) has a restraint direction non-parallel to global. Therefore, the only local joint reference frame which is non-parallel to global is at joint 4.. 3 - 13.

(40) Global and Local Coordinate Reference Frames. Figure 3.7 Local Joint Reference Frames. 3 - 14. General.

(41) General. 4.. General Commands and File Management. General Commands and File Management This Chapter describes the concept of "list" processing, default command file processing, general commands, and files created by GTSTRUDL, as follows: Commands and Concepts. Description. 4.1. "list" Processing. Forms of lists of names. 4.2. STRUDL. Initiate execution. 4.3. FINISH. Terminate execution and exit. 4.4. CINPUT. Read an external input file. 4.5. COUTPUT. Output to an external file. 4.6. FLIST 1 and FLIST 2. Display system and user data files. 4.7. SCAN Error Notice. Error notification control. 4.8. BYPASS. Bypass following commands. 4.9. UNITS. Specify current units. 4.10. QUERY. Summarize current status. 4.11. DEFINE GROUP. Assigns collections of joint, member, finite element, or loading names to GROUP names. 4.12. PRINT GROUP. Print group data. 4.13. DELETE GROUP. Delete group data. 4.14. PRINT GENERATE. Controls output from automatic mesh generation commands. 4.15.. CONSISTENCY CHECK. Perform a data consistency check. 4.16. OPEN USERDATA FILE. Open new or existing user data set. 4.17. Files Created by GTSTRUDL. Description of files created by GTSTRUDL. 4-1.

(42) General Commands and File Management. General. 4.18. The GTSTRUDL Batch Processor Run one or more GTSTRUDL command files in a batch mode. 4.19. LARGE PROBLEM SIZE. Improve analysis performance for very large problems and speed of data base RESTORE processing. 4.20. RUN. Run DOS commands from a GTSTRUDL command. 4.21. ALIGN. Adjust coordinates to assure members are parallel to the global Y-axis. 4.22. NOTES. Specify and store notes in connection with a structural model. 4.23. PRINT COMMAND ARCHIVE. Print commands and comments that are archived in files associated with data base SAVE files.. 4.24. ACTIVE SOLVER. Perform all subsequent static analyses using the GT64M or GTSES solvers, and Eigen solving using the GTSELANCZOS solver. 4.25. DEFINE PHYSICAL MEMBER SMOOTH PHYSICAL MEMBER. Define and smooth the design of physical members. 4-2.

(43) General Commands. 4.1. "list" Options. "list" Options. Command elements:. Note:. The words JOINT or NODE and MEMBER or ELEMENT are synonymous and may be used interchangeably.. 4-3.

(44) "list" Options. General Commands. Command elements: alphalist integerlist 'a1' ('a2').... = = =. i1 (i2) ........ id1, id2. = =. n3. =. id4. =. id5, id6. =. n7. =. 'a1' ('a2'). . . i1 (i2) . . . alphanumeric names each of from 1 to 8 characters enclosed in single quotes (apostrophes). positive integer names first and last names (integer or alphanumeric) of a name sequence. integer increment used to generate the name sequence. If not specified, n3 = 1 or -1 depending on the value of id1 and id2. the name (integer or alphanumeric) of a previously defined GROUP name (Chapter 4.13). first and last names (integer or alphanumeric) of a previously defined GROUP name (Chapter 4.13) sequence. integer increment used to generate the GROUP name sequence. If not specified, n7 = 1 or -1 depending on the value of id5 and id6.. Example DEFINE GROUP 'COLINE-A' MEMBERS 301 TO 320 DEFINE GROUP 'COLINE-B' MEMBERS 401 TO 420 MEMBER PROPERTIES EXISTING AX 100 IZ 10000 $ For ALL currently active members CONSTANTS BETA 90 MEMBERS 1 TO 31 BY 2 BETA 45 MEMBERS 101 107 200 TO 209 GRP LIST 'COLINE-A' 'COLINE-B' DENSITY EXISTING 490. BUT 301 305 GRP 'COLINE-B' LOADING 1 'APPLIED MEMBER LOADS' MEMBER LOADS EXISTING FOR Y UNIF W -1.5 $ Applied to all currently active members C C C STIFFNESS ANALYSIS LOAD LIST 1 2 3 LIST FORCES MEMBERS GRP 'COLINE-A' LIST FORCES MEMBERS GRP 'COLINE-B'. 4-4.

(45) General Commands. "list" Options. Explanation In GTSTRUDL, all joints, members, finite elements, and independent and dependent loading conditions have names (id's) associated with them. These names can either be positive integer numbers, or they can be strings of from 1 to 8 alphanumeric characters (other than reserved characters such as the single quote or $ characters) enclosed in single quotes (apostrophes). The names are established and stored in the problem data base (Section 5.2) at the time a joint, member, finite element, or loading is referenced the first time in a GTSTRUDL execution, or during the creation of a finite element model using GTMenu. Where the word "list" appears in a command description in this User Guide, and unless otherwise described, it means that a list of names may be given in the form described above. Whenever a list of names is given in a command, the list may refer only to one type of entity (i.e., joints, members and finite elements, or loading conditions). Examples of different forms of "list" are presented after the following description of how the different forms of "list" operate: 1.. alphalist: This is a list of names where each name consists of a string of from 1 to 8 alphanumeric characters (other than reserved characters such as the single quote or $ characters) enclosed in single quotes (apostrophes).. 2.. integerlist: This is a list of positive integer numbers in any sequence.. 3.. id1 TO id2 BY n3: This is a list of consecutive names. The names are incremented or decremented as follows: a.. If the "BY n3" option is given, then n3 may be a positive or negative integer and the names are incremented or decremented accordingly.. b.. If the "BY n3" option is not given, then the names id1 TO id2 are incremented from id1 TO id2 by 1 if id1 is less than id2, or decremented from id1 TO id2 by -1 if id1 is greater than id2.. 4-5.

(46) "list" Options. General Commands. c.. If id1 and id2 are alphanumeric names, then they are incremented or decremented as follows: (1). The alphanumeric name must be composed of two parts which are an alphanumeric prefix and an integer suffix. The alphanumeric prefix consists of the first string of characters in the name where the last character in the prefix is a character other than the integers 0 9. For example: 'BEAM10' 'COLA-15' 'ABC*100' In the above names, the alphanumeric prefixes are "BEAM", "COLA", and "ABC*" respectively, while the integer suffixes are "10", "15", and "100" respectively.. (2). 4.. The integer suffix is then incremented/decremented according to the "BY n3" option.. GROUP or GRP: A GROUP (Section 4.12) is associated with a list of joint, member and finite element, and/or loading condition names. When the GROUP option is used, the group name is simply the name of a group which in turn is associated with a list of joint, member and finite element, and/or loading condition names. GROUP names may be specified as follows: (a). id4: Only one GROUP name may follow the word GROUP or GRP. The GROUP name may be a positive integer number or an alphanumeric string of from 1 to 8 characters enclosed in single quotes. If several GROUP names are to be given, then the LIST option must be used.. (b). LIST: This option allows one or more GROUP names to be given as described by "group-list". If additional joint, member and finite element, or loading condition names are to be given in the "listi", then the list of GROUP names must first be followed by the word JOINT, NODE, MEMBER, ELEMENT, or LOAD.. 4-6.

(47) General Commands. 5.. "list" Options. EXISTING: The "alphalist", "integerlist", "id1 TO id2 BY n3", and GROUP options of specifying names requires using explicit names. For example, you cannot use the word "ALL" to mean all the joints, members, finite elements, or both members and finite elements. The "EXISTING" option provides a means of specifying "ALL". The word "ALL" is not permitted as part of a "list" since it will conflict with its use in certain other commands. The use of EXISTING is context dependent. For example, it can mean all joints, or all members, or all finite elements, or all members and finite elements depending on the command in which EXISTING is used. Further, EXISTING only applies to the "structural components" referred to as joints, members, and finite elements, but not to loading conditions. EXISTING operates as follows: (a). If the MEMBERS, ELEMENTS, NLS or CABLES ONLY option is not given, then EXISTING refers to joint names, or member and finite element names. ACTIVE is the default.. (b). If the MEMBERS, ELEMENTS, NLS or CABLES ONLY option is given, then EXISTING refers ONLY to MEMBERS, ELEMENTS (i.e., finite elements), NLS (i.e., nonlinear springs), or CABLES (i.e., cable finite elements). ACTIVE is the default.. (c). Only ACTIVE, INACTIVE, or both ACTIVE and INACTIVE structural components will be referenced depending on the use of the respective word. ACTIVE is the default.. (d). Any name that is given in, or implied by, the "list2" or "BUT list3" options will be used as long as the name exists in the current GTSTRUDL data base (i.e., it has been referenced in a previous command and has not been previously deleted). Any name given or implied by list2 and list3 that does not exist in the current data base is ignored during the processing of these lists (i.e., such nonexistent names are neither created nor added to the data base).. (e). If a "list2" has been given, then only the names that exist in the current GTSTRUDL data base are used (i.e., the names that have been referenced in previous commands and which have not been previously deleted are used). The other names in the "list2" are ignored.. (f). If a "list2" has not been given, then all names that exist in the current GTSTRUDL data base for the particular structural component being referenced are used (i.e., all the names that have been referenced in previous commands and which have not been previously deleted are used).. 4-7.

(48) "list" Options. General Commands. (g). (h). Any name that is from the "BUT list3" option operates as follows: (1). If a "list2" has been given, then the names used from "list3" are subtracted from the names used from "list2". The remaining names are then sorted in the same order as is ordered by the OUTPUT ORDERED command (Section 13.2).. (2). If a "list2" has not been given, then the names used from "list3" are subtracted from all names that currently exist in the data base for the particular structural component being referenced by the command in which EXISTING is used. The remaining names are then sorted in the same order as is ordered by the OUTPUT ORDERED command (Section 13.2).. Any name that is given in, or implied by, the "PLUS list4" option will be used if it exists in the current GTSTRUDL data base or, if it does not exist in the current data base, it will be created and placed in the data base as a new existing structural component.. Examples of Different Forms of "list" 4 or 'COLUMN1': A single name is a list. 'L2', 105, 'LOAD1' 'LOAD2' 4 5:. 'J9' 6 TO 10 23 25:. Integer and alphanumeric names can be mixed, and spaces and commas are equivalent.. This list contains eight names which are: 'J9', 6, 7, 8, 9, 10, 23 and 25.. 17, 18, 21, 2 TO 10 BY 2, 22 TO 13 BY -3, 33 TO 29: This list contains seventeen names which are: 17, 18, 21, 2, 4, 6, 8, 10, 22, 19, 16, 13, 33, 32, 31, 30 and 29.. 4-8.

(49) General Commands. "list" Options. 'JT-3' TO 'JT-7': This list contains seven names which are: 'JT-3' 'JT-4' 'JT-5' 'JT-6' 'JT-7' GRP 1 GRP 2 GRP 3 10 TO 15 This list will contain the names associated with GROUP 1, 2 and 3, and the structural component names 10, 11, 12, 13, 14 and 15. GRP LIST 1 TO 7 BY 2 4 10 This list will contain the names associated with GROUP 1, 3, 5, 7, 4 and 10. GROUP LIST 1 TO 4 7 JOINT 17 19 This list will contain the joint names associated with GROUP 1, 2, 3, 4 and 7, and the joint names 17 and 19 . EXISTING Depending on the context of the command, all names of currently active structural components are included in this list. For example, all active joints, or all active members and finite elements. EXISTING 1 TO 100 This list will contain the names of all currently active structural components whose names lie in the range of 1 to 100. Any names in the range of 1 to 100 that are the names of inactive structural components, or which do not exist in the current GTSTRUDL data base are ignored. For example, all active members and finite elements whose names lie in the range 1 to 100. EXISTING ELEMENTS ONLY This list will only contain the names of all currently active finite elements. EXISTING MEMBERS ONLY This list will only contain the names of all currently active members.. 4-9.

(50) "list" Options. General Commands. EXISTING INACTIVE All names of currently inactive structural components are included in this list. EXISTING BUT 4 TO 12 BY 2 The names of all currently active structural components, except for those whose names are 4, 6, 8, 10, or 12, are included in this list. EXISTING MEMBERS ONLY 1 TO 20 BUT 5 TO 17 BY 3 The names of all currently active members whose names lie in the range 1 to 20, except those whose names are 5, 8, 11, 14 or 17, are included in this list. EXISTING PLUS 201 to 231 by 2 The names of all currently active structural components, plus those structural components whose names lie in the range 201 to 231 by 2, are included in this list. In addition, any structural components whose names do not appear in the range 201 to 231 by 2 are created and added to the currently active GTSTRUDL data base, and they are included in this list of names. 1 TO 11 BY 3 The sequence 1, 4, 7, 10 is generated, but a warning message is issued stating that the incrementation sequence does not terminate on the number 11. In this case, the number 11 is ignored. 'A1' TO 'B5' The alphanumeric prefixes in the range of names are not the same. The two names specified are ignored. GROUP LIST 1 TO 5 10 15 MEMBER 54 If the GROUP option is given in a command that references JOINT names, the word MEMBER will cause list processing for the joint list to terminate. The joint names 1, 2, 3, 4, 5, 10 and 15 may or may not be processed depending on the command in which this was given.. 4 - 10.

(51) General Commands. 4.2. STRUDL Command. STRUDL Command STRUDL ('a') ('title') Command elements: 'a'. = an optional problem name of from 1 to 8 characters.. 'title'. = an optional problem title of from 1 to 64 characters.. Example STRUDL 'JOB-123' 'BRIDGE AT HIGHWAY I-85/I-285'. Explanation On PC’s, the STRUDL command is no longer required. However, if given within an existing execution of GTSTRUDL, it will initiate a new GTSTRUDL execution for which a problem data base does not currently exist. The RESTORE command (Section 5.3) is the first command in a GTSTRUDL problem for which a data base does exist. The STRUDL command causes the following to occur: 1.. Initialize a working GTSTRUDL problem data base (Section 5.2) which will contain information specified by the engineer in the commands that follow the STRUDL command, and will contain information created by GTSTRUDL such as the results of analysis and design,. 2.. Unless the user modifies the default units, sets the default units as follows: INCHES, POUNDS, RADIANS, FAHRENHEIT, AND SECONDS, and. 3.. Sets the ADDITIONS mode for subsequent processing of commands.. Following the STRUDL command, the user may specify any number of other commands (such as UNITS, GENERATE JOINTS, STIFFNESS ANALYSIS, LIST FORCES, etc.).. 4 - 11.

(52) FINISH Command. 4.3. General Commands. FINISH Command. FINISH. Explanation The FINISH command is used to terminate the execution of GTSTRUDL command processing and graphic al display. It should be noted that if it is desired to save all information in the current GTSTRUDL Data Base (Section 5), it is necessary to issue the SAVE command (Section 5.3) prior to the FINISH command.. 4 - 12.

(53) Input. 4.4. CINPUT Command. CINPUT Command. command element, ‘filename’. =. Any valid permanent file specification enclosed in single quotes. Filename is the file containing GTSTRUDL commands to be read.. Example CINPUT 'BRIDGE1.DAT' C C C GTMenu $ Enter the GTMenu Graphical User Interface to view the structure $ Exit GtMenu STIFFNESS ANALYSIS C C C. Explanation The CINPUT command is used to read subsequent commands from an alternate file, and it is used to cause GTSTRUDL to alternate reading of commands between the terminal keyboard or a batch file of commands, and an alternate file of commands.. 4 - 13.

(54) CINPUT Command. Input. The CINPUT command operates as follows: 1.. CINPUT 'filename': This form of the command causes subsequent commands to be read from an alternate input file called 'filename'. 'filename' may be any valid file specification including references to directory and subdirectory names. The file 'filename' may contain any valid command that normally can be processed from a file of commands. The STRUDL command may be included in the file 'filename'.. 2.. CINPUT STANDARD: This form of the command may be included in the alternate input file 'filename'. When this command is encountered during processing of commands in the file 'filename', GTSTRUDL will return control of command processing back to the primary input device from which subsequent commands will be read.. 3.. CINPUT RESUME: This form of the command may be given from the primary input device. If it is given, GTSTRUDL will return control of command processing to the alternate file 'filename' beginning with the command in the alternate file immediately following the most recent CINPUT STANDARD command processed in the alternate input file. If another CINPUT STANDARD command is subsequently encountered in the alternate input file, control of command processing will be returned to the primary input device.. Figure 4.4-1 shows how the above three forms of the CINPUT command operate.. CHANGES, and DELETIONS Modes The CINPUT command is mode independent. That is, it operates the same in the ADDITIONS, CHANGES and DELETIONS modes.. 4 - 14.

(55) Input. CINPUT Command. Figure 4.4-1 Operation of the CINPUT Command. 4 - 15.

(56) CINPUT Command. Input. Extended Example In this example (Figure 4.4-2), the following commands are input from the keyboard, or from a file of commands: STRUDL $ $ Input joint coordinates, support boundary conditions, and finite $ element incidences from an alternate file 'GATEGEOM.DAT' $ CINPUT 'GATEGEOM.DAT' $ $ Input finite element and material properties from an alternate file $ 'GATEPROP.DAT' $ CINPUT 'GATEPROP.DAT' $ $ Input loading descriptions from an alternate file 'GATELOAD.DAT' $ CINPUT 'GATELOAD.DAT' $ QUERY GTMenu $ GTMenu can be entered from a menu pick C C $ Additional commands input from the primary input device C STIFFNESS ANALYSIS UNITS CM LIST DISPLACEMENTS UNITS MTON M LIST REACTIONS FINISH. 4 - 16.

(57) Input. CINPUT Command. Figure 4.4-2 CINPUT Example 1 4 - 17.

(58) COUTPUT Command. 4.5. Output. COUTPUT Command. command elements, 'filename'. =. Any valid permanent file specification of up to 256 alphanumeric characters and enclosed in single quotes. Filename is the file into which output caused by subsequent POL commands will be written.. Example STRUDL UNITS KN M C C $ Additional commands describing the structure model C STIFFNESS ANALYSIS UNITS CM MTONS COUTPUT 'DISPL.OUT' LIST DISPLACEMENTS COUTPUT 'FORCES.OUT' LIST FORCES COUTPUT STANDARD LIST SUM REACTIONS C C $ Additional commands C. 4 - 18.

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