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When using the "deformations" on the element recorder for a CorotTruss element, what is the output composed of? I thought that it was strain but the values appear to be too large. Are they the same as the basic unit that one has defined?

I have created an optimization algorithm to run with OpenSees. I ran it successfully on an Windows Server 2003. While running it there I have not had trouble with convergence. However, when I run it on my Vista laptop, I repeatedly get the following error. WARNING: CTestEnergyIncr::test() - failed t...

I want to run the complete earthquake record from the PEER database. I am using the same set up as in Example 6 (ReadSMD) but I have a question about the Tmaxanalysis variable. When I specify 10 seconds with a time increment of .01, does that mean that only the first 10 seconds of the EQ record are ...

I have been using the element recorder to determine the stress and the strain in the material for a corotational truss. However, I noticed that when I specify the material tag number, I get a file with just the time steps in it. But if I omit the material tag and ask for strain (as shown below) I ge...

I am modeling a Buckling-Restrained brace frame. I am using a corotTruss element since I understand that the truss element will not buckle. To do this I need a trilinear hysteretic material that doesn't have degradation. I have tried using the Hysteretic material but the stress strain plot doesn't p...

I got it.

If you use the remove recorders along with reset and wipeAnalysis, you don't have to rebuild the structure completely.

Something that I noticed in my recorder is that it resets the time and returns more results. In other words, after running from 0-10, for example, there are a few more values for from 0-10. Is that normal? I think that the problem lies in the recorder is recording after that earthquake is done. (I a...

Ok, I got it to work.

For other users, there is a difference between the dash and the minus sign on the ten key pad (even though they might appear the same). That is something to check when recorders don't work; make sure that the dash was used.

Thanks for all the help Silvia.

Another idea is that I am creating the truss with the area and the material tag. Since I don't understand fully how the recorder formulates its response, is there a possibility that I need to define a section and then try to use the recorder?

I did pass it the right element tag. I have OpenSees output the element tag so that I can ensure that it is using the right one. I changed it to a regular truss and it still came up with a blank file. I need to use the corotTruss element to avoid some potential convergence issues that may arise. Her...

I removed the quotes from the recorder but I still end up with an empty file. The interesting thing is that the drift recorder is set up in the same way (with the quotes0 and it does return values. I know that there is force in the element since there is a large change in the displacement of the bui...

I tried it with axialForce and stiff alone. But I still ended up with a blank output file. Any other ideas?

Thanks.

On my model the element recorder output file is empty. All my other recorders work fine. Is there a reason. I am using a corotational truss and here is the line of code that forms the recorder: recorder Element -file "$dataDir/$FileName/$ii/ElementForce$level Eq[expr $num+1].out" –time –el...

For the drift recorder, is the relative displacement the amount of displacement that occured during that time step or the cumulative displacement since the start of the analysis? And is the displacement returned from the node recorder also the displacement that occured during that time step or the c...

The drift recorder is not clear to me. In the manual, it says: The drift is taken as the ratio between the prescribed relative displacement and the specified distance between the nodes. 1. So the output file contains a ratio, right? 2. What is the displacement relative to? Is it relative to the prev...