Example 8

[Elina]

Hello!
I want to find out the dominant (first) period of the building of the Example 8. So, I source file "Ex8.genericFrame3D.build.RCsec.tcl" just to define masses etc and I choose Modeshape 1. When I analyze for fibersection everything is OK (Mode=1 Period=0.481 sec), but with Elastic section this message comes out :

"BandArpackSolver::Maximum number of iteration reached.
goGravity
Model Built
OpenSees >"
and the period is =>2755776668030087......

What's going on???

Thanks!!!

[silvia]

check how you defined the section.
_________________
Silvia Mazzoni, PhD
OpenSees-NEESit Simulation User Support Manager
University of California, Berkeley

[Elina]

I didn't change anything at the file. I downloaded the examples file and i just sourced file "Ex8.genericFrame3D.build.RCsec"

When you run the example just for gravity loads and an elastic section is everything ok?

[silvia]

i'll try it.
_________________
Silvia Mazzoni, PhD
OpenSees-NEESit Simulation User Support Manager
University of California, Berkeley

[silvia]

i sourced the same file and it gave me an error that it didn't know the variable cover. my mistake.
when you fix the recorder commands with an if statement:

[code]if {$SectionType == "FiberSection"} {
set yFiber [expr $HCol/2-$cover]; # fiber location for stress-strain recorder, local coords
set zFiber [expr $BCol/2-$cover]; # fiber location for stress-strain recorder, local coords
recorder Element -file $dataDir/SSconcEle1sec1.out -time -ele $FirstColumn section $numIntgrPts fiber $yFiber $zFiber $IDconcCore stressStrain; # steel fiber stress-strain, node i
recorder Element -file $dataDir/SSreinfEle1sec1.out -time -ele $FirstColumn section $numIntgrPts fiber $yFiber $zFiber $IDSteel stressStrain; # steel fiber stress-strain, node i
}[/code]

it works.
_________________
Silvia Mazzoni, PhD
OpenSees-NEESit Simulation User Support Manager
University of California, Berkeley

[silvia]

here is what i get:
OpenSees > source ex8.genericframe3d.build.rcsec.tcl
Number of Stories in Y: 2 Number of bays in X: 2 Number of bays in Z: 2
goGravity
Model Built
OpenSees >


what version of OpenSees are you using????
_________________
Silvia Mazzoni, PhD
OpenSees-NEESit Simulation User Support Manager
University of California, Berkeley

[Elina]

Don't worry about the variable "cover" I had already inserted an if command as you proposed...
The version I have is 2.1.0.

[silvia]

it works fine for me.....
_________________
Silvia Mazzoni, PhD
OpenSees-NEESit Simulation User Support Manager
University of California, Berkeley

[Elina]

Even for an elastic section???

[silvia]

..... yes......
let me test it with the latest downloaded opensees.exe.
_________________
Silvia Mazzoni, PhD
OpenSees-NEESit Simulation User Support Manager
University of California, Berkeley

[silvia]

please restart from the original file, it works fine for me, after making the recorder-command edit.
_________________
Silvia Mazzoni, PhD
OpenSees-NEESit Simulation User Support Manager
University of California, Berkeley

[Elina]

I just found out that if I choose to see the deformed shape everything is ok....
but if I change it to ModeShape:

# Define DISPLAY -------------------------------------------------------------
DisplayModel3D ModeShape ; # options: DeformedShape NodeNumbers ModeShape

then I have a problem....
It must be something with the eigen analysis at "DisplayModel3D" file.

If I find what's going on I'll let you know...

One more question : Why large torsional stiffness is assumed??

Thank for your time!

[silvia]

just because, I guess.
_________________
Silvia Mazzoni, PhD
OpenSees-NEESit Simulation User Support Manager
University of California, Berkeley