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suuzie

It seems that compiling OpenSees using VisualStudio instead of downloading it form OpenSees website can mitigate the problem. The instructions on how to compile OpenSees on your computer available from some YouTube:

https://www.youtube.com/watch?v=BLcY1w7a5Ec
AND
https://www.youtube.com/watch?v=cOsAYr6zVwM

suuzie

Today I downloaded the latest version of OpenSees (Version 3.5.0 64-Bit).
The last update of my OpenSees was 2 years ago, and I found a few differences between the old one and the new one.

I needed to install Tcl when I installed the old one, but this time it seemed that I just needed to download OpenSees.

Another thing I noticed was that my structure was not displayed when I run modal analysis (mode shapes) and pushover analysis.

I want to see the mode shape of my structure when I run modal analysis, and also I want to see how the structure deforms when I run pushover analysis.

Is there any way to display my structure using the latest version of OpenSees (Version 3.5.0 64-Bit)?

suuzie

Thanks #selimgunay for your response.

In case I want to use tangent stiffness proportional damping with instantaneous frequency, how can I get that instantaneous frequency?
I think usually the modal analysis result gives us the first modal frequency (but not the instantaneous.)

If we take a look at the dynamic analysis example on OpenSees wiki page (https://opensees.berkeley.edu/wiki/inde ... ment_Frame), the modal analysis is conducted using the following sentences:

# Eigenvalue Analysis
set pi [expr 2.0*asin(1.0)]; # Definition of pi
set nEigenI 1; # mode i = 1
set nEigenJ 2; # mode j = 2
set lambdaN [eigen [expr $nEigenJ]]; # eigenvalue analysis for nEigenJ modes
set lambdaI [lindex $lambdaN [expr 0]]; # eigenvalue mode i = 1
set lambdaJ [lindex $lambdaN [expr $nEigenJ-1]]; # eigenvalue mode j = 2
set w1 [expr pow($lambdaI,0.5)]; # w1 (1st mode circular frequency)
set w2 [expr pow($lambdaJ,0.5)]; # w2 (2nd mode circular frequency)
set T1 [expr 2.0*$pi/$w1]; # 1st mode period of the structure
set T2 [expr 2.0*$pi/$w2]; # 2nd mode period of the structure
puts "T1 = $T1 s"; # display the first mode period in the command window
puts "T2 = $T2 s"; # display the second mode period in the command window

Can I still use these sentences to obtain the instantaneous frequency? Or should I place this sentence in other places?

suuzie

Hi,

Can you tell me what is the meaning of the error message that I get from the example "Dynamic Analysis of 2-Story Moment Frame" (on OpenSees Wiki page)? When I source the .tcl file, I get the following message:

WARNING: analysis .. TransientAnalysis already exists => wipeAnalysis not invoked, problems may arise

The example is from the following website:
https://opensees.berkeley.edu/wiki/inde ... ment_Frame

It seems when I remove the "Eigenvalue Analysis" section, the above error message does not appear.. I am using OpenSees with version 3.3.0 64-Bit.

suuzie

Dear Sir/Madam:

I would like to know how to write in .tcl file tangent stiffness proportional damping on updated frequencies?
This tangent stiffness proportional damping on updated frequencies is discussed in references such as:

Finley A. Charney, "Unintended Consequences of Modeling Damping in Structures", J. Struct. Engrg. Volume 134, Issue 4, pp. 581-592 (April 2008).

Anil K. Chopra and Frank McKenna, "Modeling viscous damping in nonlinear response history analysis of buildings for earthquake excitation", J. Earth Eng & Struct. Dyn,. Volume 45, Issue 2, pp. 193-211 (February 2016).

I know how to write initial stiffness proportional damping, that is (based on the opensees wiki page "https://opensees.berkeley.edu/wiki/inde ... ng_Command"):

rayleigh $alphaM $betaK $betaKinit $betaKcomm

where (f1, f2: frequencies; zeta1,zeta2:damping ratios):

$alphaM = 4pi*f1*f2*(zeta1*f2-zeta2*f1)/(f2^2-f1^2)

$betaK = 0

$betaKinit = (zeta2*f2-zeta1*f1)/(pi*(f2^2-f1^2))

$betaKcomm = 0

Can you please tell me how to specify $alphaM $betaK $betaKinit $betaKcomm for the tangent stiffness proportional damping on updated frequencies in OpenSees?

suuzie

Hello,

I want to know how I can use timeSeries when I have different time step for each step (corresponding to each data in displacement history).
For example, can I write time step in a file like displacement history and then use it?? How can I do that?

Thanks!

suuzie

Hello,

I found that the example for "ZeroLengthImpact3D" element generates zero-reaction, which is different from the output provided by the author of this element.
It seems this element is corrupted, or hasn't been adjusted to the latest version of OpenSees (v2.5.0).

suuzie

Hello,

I got a following error message when I run analysis that place static loading on my structure:

WARNING BandGenLinSOE::BandGenLinSOE : ran out of memory for A (size,super,sub) (22533, 22514, 22514)
StaticAnalysis::handle() - LinearSOE::setSize() failedStaticAnalysis::analyze() - domainChanged failed at step 0 of 10
OpenSees > analyze failed, returned: -1 error flag

I would like to know what is this error message and how I can handle this.

suuzie

Hi,

I wonder if we can record modal properties (modal displacement or modal period) per each time step.
For example, the bridges with nonlinear materials have different period when the structure enters inelastic response under strong earthquake motion.

If this is possible, how can we write the recorder command?

Best,
Suuzie.

The OpenSees Community

Search found 9 matches

Re: Problem in Displaying Modal Shape, Push-over Analysis, etc.

Problem in Displaying Modal Shape, Push-over Analysis, etc.

Re: Tangent Stiffness Proportional Damping on Updated Frequencies

Error message from example "Dynamic Analysis of 2-Story Moment Frame"

Tangent Stiffness Proportional Damping on Updated Frequencies

Different Time Step at each Step

Problem in Example for "ZeroLengthImpact3D"

Error Message !!EXPLANATION NEEDED!!

Record Modal Properties