×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

etabs plus and sequential construction case

etabs plus and sequential construction case

etabs plus and sequential construction case

(OP)
I am designing a building without a column in the first story. I´ve found that if I run an elastic analysis and then I define a sequential construction case, etabs plus v.909 makes an analysis and gives results that makes sense. But I am not sure that etabs plus results are correct, because manual refers to etabs nonlinear when you ask about sequential construction. Could some body tell me more about this topic.

RE: etabs plus and sequential construction case

I believe you need to have ETABS nonlinear version to run a sequential construction analysis. However, when you first install ETABS, it defaults for some time period (30 days?) nonlinear version, even if you purchased a lesser version, or until you get a permanent license file. I assume that you went under the Define menu to Add a sequential construction case. The thing is, with ETABS, to do sequential construction, you must make two analyses. First run your regular analysis, then you have go back again under the Analyze menu to run the Contruction sequence nonlinear analysis. In your situation where you are using a tranfer girder on the first story, that is a typical application where the stage construction might give some insightful results compared to a linear Dead case analysis. Keep in mind that ETABS stage construction (to my knowledge) is only additive, in that you can add stories and/or groups, but not remove elements or group as part of the sequential construction analysis. good luck.

RE: etabs plus and sequential construction case

(OP)
I think Etabs Plus has an open
door to the sequential analysis if you define the
dead-sq after you run the static analysis, that is the
statement I wrote by first. Please follow this steps
with any model you have: delete any dead-sq case, run
static analysis, define a dead-sq case, run the
sequential construction case, and you will obtain this
analysis run log:

Program ETABS Version 9.0.9.0    File:modelo secuencial similar al tutorial.LOG
                                                                     
 BLOQUE 5                                                              


 B E G I N   A N A L Y S I S                                2006/08/18  22:58:53

 MAXIMUM MEMORY BLOCK SIZE (BYTES)         =      31.962 MB


 E L E M E N T   F O R M A T I O N                                      22:58:53

 NUMBER OF JOINT  ELEMENTS FORMED          =          79
 NUMBER OF SPRING ELEMENTS FORMED          =           0
 NUMBER OF FRAME  ELEMENTS FORMED          =         159


 E Q U A T I O N   S O L U T I O N                                      22:58:53

 TOTAL NUMBER OF EQUILIBRIUM EQUATIONS     =         207
 APPROXIMATE "EFFECTIVE" BAND WIDTH        =          33

 NUMBER OF EQUATION STORAGE BLOCKS         =           1
 MAXIMUM BLOCK SIZE (8-BYTE TERMS)         =        6447
 SIZE OF STIFFNESS FILE(S) (BYTES)         =      51.191 KB

 NUMBER OF EQUATIONS TO SOLVE              =         207
 NUMBER OF STATIC LOAD CASES               =           4
 NUMBER OF ACCELERATION LOADS              =           6
 NUMBER OF NONLINEAR DEFORMATION LOADS     =           0


 J O I N T   O U T P U T                                                22:58:53

 G L O B A L   F O R C E   B A L A N C E   R E L A T I V E   E R R O R S

 PERCENT FORCE AND MOMENT ERROR AT THE ORIGIN, IN GLOBAL COORDINATES

    LOAD          FX          FY          FZ          MX          MY          MZ
DEAD        3.26E-15     .000000    1.18E-13    0.478953    6.80E-14    0.015486
TRIBUTAR     .000000     .000000     .000000     .000000     .000000     .000000
SX           .000000     .000000     .000000     .000000     .000000     .000000
SY           .000000     .000000     .000000     .000000     .000000     .000000

    SPEC          FX          FY          FZ          MX          MY          MZ
SX           .000000     .000000     .000000     .000000     .000000     .000000
SY           .000000     .000000     .000000     .000000     .000000     .000000


 E L E M E N T   J O I N T - F O R C E   O U T P U T                    22:58:53

 NUMBER OF JOINT  ELEMENTS SAVED           =          79
 NUMBER OF FRAME  ELEMENTS SAVED           =         159


 E L E M E N T   O U T P U T                                            22:58:53



 A N A L Y S I S   C O M P L E T E                          2006/08/18  22:58:53


 Program ETABS Version 9.0.9.0    File:modelo secuencial similar al tutorial.LOG
                                                                     
 BLOQUE 5                                                              


 B E G I N   A N A L Y S I S                                2006/08/18  22:58:54

 MAXIMUM MEMORY BLOCK SIZE (BYTES)         =      31.962 MB


 E L E M E N T   F O R M A T I O N                                      22:58:54

 NUMBER OF JOINT  ELEMENTS FORMED          =          79
 NUMBER OF SPRING ELEMENTS FORMED          =           0


 L O A D   R E - S O L U T I O N                                        22:58:54

 NUMBER OF STATIC LOAD CASES               =           4


 E L E M E N T   J O I N T - F O R C E   O U T P U T                    22:58:55

 NUMBER OF JOINT  ELEMENTS SAVED           =          79
 NUMBER OF FRAME  ELEMENTS SAVED           =         159


 A N A L Y S I S   C O M P L E T E                          2006/08/18  22:58:55


 Program ETABS Version 9.0.9.0    File:modelo secuencial similar al tutorial.LOG
                                                                     
 BLOQUE 5                                                              


 N O N L I N E A R   S T A T I C   A N A L Y S I S          2006/08/18  22:59:28

 MAXIMUM MEMORY BLOCK SIZE (BYTES)         =      31.962 MB
  
 NONLINEAR STATIC CASE                     =    DEAD-SQ
 CONTINUE FROM PREVIOUS CASE               =           0
  
 LOAD CONTROL TYPE                         =       FORCE
 METHOD TO USE WHEN HINGES DROP LOAD       =      UNLOAD
 TYPE OF GEOMETRIC NONLINEARITY            =        NONE
 SAVE POSITIVE INCREMENTS ONLY             =         YES
  
 MINIMUM NUMBER OF SAVED STEPS             =           1
 MAXIMUM NUMBER OF SAVED STEPS             =          50
 MAXIMUM NUMBER OF NULL STEPS              =          50
 MAXIMUM NUMBER OF TOTAL STEPS             =         200
 MAXIMUM NUMBER OF ITERATIONS PER STEP     =          10
  
 RELATIVE FORCE CONVERGENCE TOLERANCE      =    0.000100
 RELATIVE EVENT TOLERANCE                  =    0.010000
  
 STAGE NUMBER                              =           1
 ENTIRE STRUCTURE IS ACTIVE                =          NO
 CHANGES TO ELEMENTS IN STRUCTURE          =        NONE

 STEP          0

 STEP          1, INCREMENT =    1.000000, SUM =    1.000000, MAX =    1.000000

 Unbalance/tolerance =    4.39E-12,  Iteration 1 converged
 Saved as Output Step          1

 TOTAL NUMBER OF CONVERGED STEPS SAVED     =           1
 TOTAL NUMBER OF CONVERGED STEPS NOT SAVED =           0
 TOTAL NUMBER OF NULL STEPS                =           0
                                               ----------
 TOTAL NUMBER OF ALL STEPS                 =           1

 TOTAL NUMBER OF ITERATIONS CONVERGED      =           1
 TOTAL NUMBER OF ITERATIONS DISCARDED      =           0
 FOR CONVERGED STEPS ONLY:
 AVERAGE NUMBER OF ITERATIONS PER STEP     =        1.00
 MAXIMUM NUMBER OF ITERATIONS PER STEP     =           1
  
 STAGE NUMBER                              =           2
 ENTIRE STRUCTURE IS ACTIVE                =          NO
 CHANGES TO ELEMENTS IN STRUCTURE          =    ADD ONLY
  

 STEP          0

 STEP          1, INCREMENT =    1.000000, SUM =    1.000000, MAX =    1.000000

 Unbalance/tolerance =    6.65E-11,  Iteration 1 converged
 Saved as Output Step          1

 TOTAL NUMBER OF CONVERGED STEPS SAVED     =           1
 TOTAL NUMBER OF CONVERGED STEPS NOT SAVED =           0
 TOTAL NUMBER OF NULL STEPS                =           0
                                               ----------
 TOTAL NUMBER OF ALL STEPS                 =           1

 TOTAL NUMBER OF ITERATIONS CONVERGED      =           1
 TOTAL NUMBER OF ITERATIONS DISCARDED      =           0
 FOR CONVERGED STEPS ONLY:
 AVERAGE NUMBER OF ITERATIONS PER STEP     =        1.00
 MAXIMUM NUMBER OF ITERATIONS PER STEP     =           1
  
 STAGE NUMBER                              =           3
 ENTIRE STRUCTURE IS ACTIVE                =          NO
 CHANGES TO ELEMENTS IN STRUCTURE          =    ADD ONLY
  

 STEP          0

 STEP          1, INCREMENT =    1.000000, SUM =    1.000000, MAX =    1.000000

 Unbalance/tolerance =    6.47E-11,  Iteration 1 converged
 Saved as Output Step          1

 TOTAL NUMBER OF CONVERGED STEPS SAVED     =           1
 TOTAL NUMBER OF CONVERGED STEPS NOT SAVED =           0
 TOTAL NUMBER OF NULL STEPS                =           0
                                               ----------
 TOTAL NUMBER OF ALL STEPS                 =           1

 TOTAL NUMBER OF ITERATIONS CONVERGED      =           1
 TOTAL NUMBER OF ITERATIONS DISCARDED      =           0
 FOR CONVERGED STEPS ONLY:
 AVERAGE NUMBER OF ITERATIONS PER STEP     =        1.00
 MAXIMUM NUMBER OF ITERATIONS PER STEP     =           1
  
 STAGE NUMBER                              =           4
 ENTIRE STRUCTURE IS ACTIVE                =         YES
 CHANGES TO ELEMENTS IN STRUCTURE          =    ADD ONLY
  

 STEP          0

 STEP          1, INCREMENT =    1.000000, SUM =    1.000000, MAX =    1.000000

 Unbalance/tolerance =    4.59E-11,  Iteration 1 converged
 Saved as Output Step          1

 TOTAL NUMBER OF CONVERGED STEPS SAVED     =           1
 TOTAL NUMBER OF CONVERGED STEPS NOT SAVED =           0
 TOTAL NUMBER OF NULL STEPS                =           0
                                               ----------
 TOTAL NUMBER OF ALL STEPS                 =           1

 TOTAL NUMBER OF ITERATIONS CONVERGED      =           1
 TOTAL NUMBER OF ITERATIONS DISCARDED      =           0
 FOR CONVERGED STEPS ONLY:
 AVERAGE NUMBER OF ITERATIONS PER STEP     =        1.00
 MAXIMUM NUMBER OF ITERATIONS PER STEP     =           1
  
 STAGE NUMBER                              =           5
 ENTIRE STRUCTURE IS ACTIVE                =         YES
 CHANGES TO ELEMENTS IN STRUCTURE          =        NONE

 STEP          0

 * * * W A R N I N G * * *
 THE APPLIED LOAD IS ZERO IN NONLIN-STATIC CASEDEAD-SQ ,
 THE ANALYSIS WILL PROCEED BUT THE STRUCTURE WILL NOT BE LOADED


 STEP          1, INCREMENT =    1.000000, SUM =    1.000000, MAX =    1.000000

 Unbalance/tolerance =     .000000,  Iteration 1 converged
 Saved as Output Step          1

 TOTAL NUMBER OF CONVERGED STEPS SAVED     =           1
 TOTAL NUMBER OF CONVERGED STEPS NOT SAVED =           0
 TOTAL NUMBER OF NULL STEPS                =           0
                                               ----------
 TOTAL NUMBER OF ALL STEPS                 =           1

 TOTAL NUMBER OF ITERATIONS CONVERGED      =           1
 TOTAL NUMBER OF ITERATIONS DISCARDED      =           0
 FOR CONVERGED STEPS ONLY:
 AVERAGE NUMBER OF ITERATIONS PER STEP     =        1.00
 MAXIMUM NUMBER OF ITERATIONS PER STEP     =           1

 TIME FOR INITIALIZING ANALYSIS            =        0.03
 TIME FOR CONTROLLING ANALYSIS             =        1.14
 TIME FOR FORMING STIFFNESS MATRIX         =        0.07
 TIME FOR SOLVING STIFFNESS MATRIX         =        0.24
 TIME FOR CALCULATING DISPLACEMENTS        =        0.00
 TIME FOR DETERMINING EVENTS               =        0.00
 TIME FOR UPDATING STATE                   =        0.04
                                               ----------
 TOTAL TIME FOR THIS ANALYSIS              =        1.52


 A N A L Y S I S   C O M P L E T E                          2006/08/18  22:59:30



Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources