problems of modal analysis

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limaochang
Posts: 9
Joined: Wed Jun 17, 2020 6:54 pm

problems of modal analysis

Post by limaochang » Tue Sep 15, 2020 6:42 pm

Hello,I am building a model of four span continuous beam bridge recently.When I run the analysis of eigen,some errors has appeared. I have put my tcl.file here,can you give me some suggestions of this model, tank you !
OpenSees > # modify2.tcl
OpenSees > logFile "modify2.log"
OpenSees > set systemTime [clock seconds]
1600222769
OpenSees >
OpenSees > puts "==============================================================================="
===============================================================================
OpenSees > puts "OpenSees Navigator: Version 2.5.7"
OpenSees Navigator: Version 2.5.7
OpenSees > puts "File sourced: E:/µ²¿é/È«ÇÅÄ£Äâ/1/modify/modify2.tcl"
File sourced: E:/碌虏驴茅/脠芦脟脜脛拢脛芒/1/modify/modify2.tcl
OpenSees > puts "Starting OpenSees analysis: [clock format $systemTime -format "%d-%b-%Y %H:%M:%S"]"
Starting OpenSees analysis: 16-Sep-2020 10:19:29
OpenSees > puts "==============================================================================="
===============================================================================
OpenSees >
OpenSees > puts "\n########################"

########################
OpenSees > puts "# Analysis-Sequence 1 #"
# Analysis-Sequence 1 #
OpenSees > puts "########################"
########################
OpenSees >
OpenSees > # Start timing of this analysis sequence
OpenSees > # --------------------------------------
OpenSees > set tStart [clock clicks -milliseconds]
1600222769996
OpenSees >
OpenSees > # Start of model generation
OpenSees > # =========================
OpenSees >
OpenSees > # Create ModelBuilder
OpenSees > # -------------------
OpenSees > model BasicBuilder -ndm 3 -ndf 6
OpenSees >
OpenSees > # Define geometry
OpenSees > # ---------------
OpenSees > source NodeCoord.tcl
OpenSees >
OpenSees > # Define Single Point Constraints
OpenSees > # -------------------------------
OpenSees > source SPConstraint.tcl
42 43 44 45 46 47
OpenSees >
OpenSees > # Define nodal masses
OpenSees > # -------------------
OpenSees > source NodeMass.tcl
OpenSees >
OpenSees > # Define Multi Point Constraints
OpenSees > # ------------------------------
OpenSees > source MPConstraint.tcl
OpenSees >
OpenSees > # Define material(s)
OpenSees > # ------------------
OpenSees > source Materials.tcl
OpenSees >
OpenSees > # Define friction model(s)
OpenSees > # ------------------------
OpenSees > source FrictionModels.tcl
OpenSees >
OpenSees > # Define section(s)
OpenSees > # -----------------
OpenSees > source Sections.tcl
OpenSees >
OpenSees > # Define geometric transformation(s)
OpenSees > # ----------------------------------
OpenSees > source GeoTran.tcl
OpenSees >
OpenSees > # Define element(s)
OpenSees > # -----------------
OpenSees > source Elements.tcl
expected floating-point number but got "-shearDist"
OpenSees >
OpenSees > # Define damping parameters
OpenSees > # -------------------------
OpenSees >
OpenSees > # Define time series
OpenSees > # ------------------
OpenSees > source TimeSeries.tcl
OpenSees >
OpenSees > # Start of analysis generation
OpenSees > # ============================
OpenSees >
OpenSees > # Get Initial Stiffness
OpenSees > # ---------------------
OpenSees > initialize
OpenSees >
OpenSees > puts "o Analysis: EigenDefaultCase"
o Analysis: EigenDefaultCase
OpenSees > # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
OpenSees >
OpenSees > # Define load pattern
OpenSees > # -------------------
OpenSees > source LoadPattern_1.tcl
OpenSees >
OpenSees > # Define recorder(s)
OpenSees > # ------------------
OpenSees > source Recorder_1.tcl
2
OpenSees >
OpenSees > # Define analysis options
OpenSees > # -----------------------
OpenSees > source AnalysisOptn_1.tcl
OpenSees >
OpenSees > # Analyze model
OpenSees > # -------------
OpenSees > set pi [expr acos(-1.0)]
3.141592653589793
OpenSees > set eigFID [open EigenDefaultCase_Node_EigenVectors_EigenVal.out w]
file91a820
OpenSees > set lambda [eigen -fullGenLapack 3]
WARNING PlainHandler::handle() - constraint matrix not identity, ignoring constraint for node 72
non-varyng assumed
WARNING PlainHandler::handle() - constraint matrix not identity, ignoring constraint for node 93
non-varyng assumed
WARNING PlainHandler::handle() - constraint matrix not identity, ignoring constraint for node 103
non-varyng assumed
WARNING PlainHandler::handle() - constraint matrix not identity, ignoring constraint for node 105
non-varyng assumed
WARNING PlainHandler::handle() - constraint matrix not identity, ignoring constraint for node 110
non-varyng assumed
WARNING PlainHandler::handle() - constraint matrix not identity, ignoring constraint for node 112
non-varyng assumed
-479898.10073334811022505164 -678.40598248962487559766 5.30501512295851362921
OpenSees > puts $eigFID " lambda omega period frequency"
OpenSees > foreach lambda $lambda {
set omega [expr sqrt($lambda)]
set period [expr 2.0*$pi/$omega]
set frequ [expr 1.0/$period]
puts $eigFID [format " %+1.6e %+1.6e %+1.6e %+1.6e" $lambda $omega $period $frequ]
}
domain error: argument not in valid range
OpenSees > close $eigFID
OpenSees >
OpenSees > # Record eigenvectors
OpenSees > # -------------------
OpenSees > record
OpenSees >
OpenSees > # Stop timing of this analysis sequence
OpenSees > # -------------------------------------
OpenSees > set tStop [clock clicks -milliseconds]
1600222770588
OpenSees > puts "o Time taken: [expr ($tStop-$tStart)/1000.0] sec"
o Time taken: 0.592 sec
OpenSees >
OpenSees > # Clean up
OpenSees > # --------
OpenSees > wipe
OpenSees > set systemTime [clock seconds]
1600222770
OpenSees > puts "\n==============================================================================="

===============================================================================
OpenSees > puts "Finished OpenSees analysis: [clock format $systemTime -format "%d-%b-%Y %H:%M:%S"]"
Finished OpenSees analysis: 16-Sep-2020 10:19:30

selimgunay
Posts: 889
Joined: Mon Sep 09, 2013 8:50 pm
Location: University of California, Berkeley

Re: problems of modal analysis

Post by selimgunay » Tue Sep 15, 2020 10:16 pm

You may need to use constraints Transformation.

Are you using equaldof, rigid diaphragm or similar multi-dof constraints?

limaochang
Posts: 9
Joined: Wed Jun 17, 2020 6:54 pm

Re: problems of modal analysis

Post by limaochang » Tue Sep 15, 2020 11:38 pm

thanks for your suggestion,actually I am using rigid links to simulate the connection between supscture and bearing.

limaochang
Posts: 9
Joined: Wed Jun 17, 2020 6:54 pm

Re: problems of modal analysis

Post by limaochang » Tue Sep 15, 2020 11:48 pm

selimgunay wrote:
Tue Sep 15, 2020 10:16 pm
You may need to use constraints Transformation.

Are you using equaldof, rigid diaphragm or similar multi-dof constraints?
thanks for your suggestion,actually I am using rigid links to simulate the connection between supscture and bearing.

mhscott
Posts: 608
Joined: Tue Jul 06, 2004 3:38 pm
Location: Corvallis, Oregon USA
Contact:

Re: problems of modal analysis

Post by mhscott » Wed Sep 16, 2020 6:25 am

Regardless, use constraints Transformation as Selim suggested.

limaochang
Posts: 9
Joined: Wed Jun 17, 2020 6:54 pm

Re: problems of modal analysis

Post by limaochang » Wed Sep 16, 2020 5:37 pm

mhscott wrote:
Wed Sep 16, 2020 6:25 am
Regardless, use constraints Transformation as Selim suggested.
Thank you !I will try.

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