Rocking wall and zero length elements

[GusO]

Hello.

I'm working on a model that has a concrete rocking wall. For this I calibrated two Zero Length Elements first in a separate model to be later integrated in the concrete wall model, but I cannot make the model run with this condition with the error message: WARNING ZeroLength::setDomain(): Element 31423 has L= 2, which is greater than the tolerance.

I've attached both models, the first one is what I want from the zero length elements and the second has the wall and the springs at the base. I'd appreciate your help.

Thanks

[kesavapraba]

Typically, a zerolength element should have its nodes at the same coordinates. Otherwise, opensees would display the warning that you received. The warning message is not an error, hence the analysis should run fine unless there are any other issues in your model.

First model: It runs fine even though there is warning. So, the warning, in this case, is not a problem.

Second model: zerolength element is not assigned to any part of your model. Please double check.

[GusO]

Thanks for you answer. I've updated my model and the zero length elements make sense now. I added extra components on the rocking wall, including post tension elements. The problem that I have is that the model stops working and converging at certain part of the load protocol and I cannot find the error.

[kesavapraba]

I would suggest you to try pushover (monotonic) analysis first. If everything goes fine, cyclic analysis can be carried out subsequently.
You should consider inputting reference load values for the cyclic analysis in the same/closer order as the lateral capacity of the wall. You can consider using penalty constraints for the analysis as MP constraints are being used at many places. Penalty factors should be provided referring to the average stiffness value from the stiffness matrix of the model.

[ymuaamar1@gmail.com]

hi, i have problem when i am running this model
WARNING ZeroLength::setDomain(): Element 28379 has L= 50, which is greater than the tolerance
WARNING ZeroLength::setDomain(): Element 28380 has L= 50, which is greater than the tolerance
WARNING ZeroLength::setDomain(): Element 28381 has L= 50, which is greater than the tolerance
WARNING ZeroLength::setDomain(): Element 28382 has L= 50, which is greater than the tolerance
WARNING ZeroLength::setDomain(): Element 28383 has L= 50, which is greater than the tolerance
WARNING ZeroLength::setDomain(): Element 28384 has L= 50, which is greater than the tolerance
WARNING No Numberer type exists (Plain, RCM only)

while executing
"numberer ParallelRCM"
(file "analysis_steps.tcl" line 6744)
invoked from within
"source analysis_steps.tcl"
(file ".\main.tcl" line 81)
Press any key to continue . . .

[kesavapraba]

Hi, Zero length element, by definition, should have L=0. However, OpenSees doesn't show error even if it is assigned to a line geometry with some length - only warning is displayed. This is exactly what shows your message. You can change L=0 or ignore warning if there is no geometric nonlinearity effect.

[STKO Team]

The warning about the zeroLength element is not an issue.
However, the next error is due to the fact you are using a model build for OpenSeesMP (parallel numberer and solver) with a sequential OpenSees