Search found 5881 matches
- Mon Nov 01, 2021 10:16 pm
- Forum: OpenSees.exe Users
- Topic: how Rayleigh Damping Command consider damping ratio for structural modes?
- Replies: 6
- Views: 10919
Re: how Rayleigh Damping Command consider damping ratio for structural modes?
1. I suggest you refer to a text book or google "rayleigh damping": https://www.orcina.com/webhelp/OrcaFlex/Content/html/Rayleighdamping,Guidance.htm https://www.usbr.gov/ssle/damsafety/TechDev/DSOTechDev/DSO-07-03.pdf 2. It cannot, from reading the text book or above links you should understand why.
- Wed Sep 15, 2021 8:57 am
- Forum: OpenSees.exe Users
- Topic: Wind Load
- Replies: 5
- Views: 10608
- Wed Sep 15, 2021 8:56 am
- Forum: OpenSees.exe Users
- Topic: Tangent Stiffness Proportional Damping on Updated Frequencies
- Replies: 4
- Views: 9921
Re: Tangent Stiffness Proportional Damping on Updated Frequencies
you can issue the eigen command any time you want .. if what you want is to change the rayleigh values after each analysis step you can put the calculations above inside an analysis loop that only does 1 step at a time .. thohj you might leave out the puts if in a loop as this will kill perforrmance...
- Wed Sep 15, 2021 8:50 am
- Forum: OpenSees.exe Users
- Topic: How to analyze the time history of earthquakes and other loads at the same time or at different times
- Replies: 2
- Views: 7427
Re: How to analyze the time history of earthquakes and other loads at the same time or at different times
create multiple load patterns, e.g. some for earthquake and some for wind, before the same analyze command.
- Wed Sep 15, 2021 8:47 am
- Forum: OpenSees.exe Users
- Topic: How does OpenSees perform dynamic analysis of earthquakes and other dynamic loads at the same time?
- Replies: 6
- Views: 10851
Re: How does OpenSees perform dynamic analysis of earthquakes and other dynamic loads at the same time?
the file contains the fluctuating values of the wind load in a specific direction. in a pattern you are providing reference loads. the actula load applied at a node at any time is equal to the load factor from the time series (in your case the load you want applied pecified in your file) multipled b...
- Wed Sep 15, 2021 8:40 am
- Forum: OpenSees.exe Users
- Topic: Does OpenSees solve least square problem?
- Replies: 4
- Views: 8435
Re: Does OpenSees solve least square problem?
1. it is the basic stiffness method. 2. the standard K matrix (assuming you are not trying to use the penalty method to enforce constraints) 3. those large values are there I presume to get some rigid constraint enforced. In reality the terms only need to be a few orders of mag larger than the coeff...
- Fri Oct 09, 2020 5:38 am
- Forum: OpenSees.exe Users
- Topic: How to assign different damping to different members in a structure
- Replies: 4
- Views: 3439
Re: How to assign different damping to different members in a structure
put the elements in different regionas and assign different damping values to the different regions
- Mon Oct 05, 2020 8:24 pm
- Forum: OpenSees.exe Users
- Topic: staged construction analysis with additional load
- Replies: 3
- Views: 3885
Re: staged construction analysis with additional load
i.e. end of file should look like the following with the loadConst added:
analyze 1
puts "##### STAGE 1 - finished #####";
loadConst -time 0.0
pattern Plain 2 Linear { load 1 0 -1000 0 0 0 0 }
analyze 1
puts "##### STAGE 2 - finished #####";
analyze 1
puts "##### STAGE 1 - finished #####";
loadConst -time 0.0
pattern Plain 2 Linear { load 1 0 -1000 0 0 0 0 }
analyze 1
puts "##### STAGE 2 - finished #####";
- Mon Oct 05, 2020 8:12 pm
- Forum: OpenSees.exe Users
- Topic: multiple relative node recorder
- Replies: 10
- Views: 7880
Re: multiple relative node recorder
here is another example in our git repo
https://github.com/OpenSees/OpenSees/bl ... ays/j1.tcl
https://github.com/OpenSees/OpenSees/bl ... ays/j1.tcl
- Mon Oct 05, 2020 7:47 pm
- Forum: OpenSees.exe Users
- Topic: About openses uniaxial material stress-strain curve
- Replies: 8
- Views: 3657
Re: About openses uniaxial material stress-strain curve
you could try another modelbuilder provided just for testing material .. here is an example i used awhile back model UniaxialMaterialTest uniaxialMaterial Elastic 1 3000 uniaxialMaterial MinMax 2 1 -min -0.001 uniaxialMaterial MinMax 3 1 -max 0.001 uniaxialMaterial MinMax 4 1 -min -0.001 -max 0.001 ...
- Wed Jun 10, 2020 2:26 pm
- Forum: OpenSees.exe Users
- Topic: Node fix problem for Modal Analysis
- Replies: 2
- Views: 3056
Re: Node fix problem for Modal Analysis
post the script so i can see how you are modeling the elements
- Wed May 06, 2020 11:45 am
- Forum: OpenSeesPy
- Topic: first post
- Replies: 5
- Views: 6757
first post
checking this works
- Tue Apr 21, 2020 3:25 pm
- Forum: OpenSees.exe Users
- Topic: The results in output file is not consistent with that on screen
- Replies: 3
- Views: 1924
Re: The results in output file is not consistent with that on screen
the results are different because the element is "CURRENTLY" (i.e I might change this) just printing forces based on end moments and element length .. the recorder is reporting element forces which are determined from basic forces transformed by the geometric transformation .. for your example you a...
- Thu Jun 28, 2018 9:48 am
- Forum: OpenSees.exe Users
- Topic: Can we apply dynamic load using Opensees?
- Replies: 8
- Views: 4393
Re: Can we apply dynamic load using Opensees?
create a load pattern with a single load on the node you wish to apply the load to .. the load actually applied during the transient analysis will be the value of the load at the node (the pseudo load) TIMES the load factor obtained from the time series.
- Tue Jun 19, 2018 3:24 am
- Forum: OpenSees.exe Users
- Topic: Error using "nDMaterial FAReinforcedConcretePlaneStress"
- Replies: 11
- Views: 11428
Re: Error using "nDMaterial FAReinforcedConcretePlaneStress"
these materials cause problems .. i have some newer materials for modeling walls .. you might even try forgetting the beam elements with these .. here is some code copied from an example put together by Dr. Petrone # Concrete # Parameters for the new concrete model set E [expr 36900e6*$Pa] ;#elastic...