change material definitions for elements during analysis

[vahidqaw]

Hi,
I have modeled a steel frame with BeamWithHinges elements. I am performing a time-history analysis on the frame and I need to update the the material behavior of the elements during the analysis. Is it possible to do it with opensees?How can I do it? Any idea? Please help me...

[fmk]

for some materials it is possible to change things after they have been defined using the parameter command .. it depends on material and which parameters you want to change .. it only works for some materials and some of the parameters .. you will need to look at the code for the materials and see what options are available to change in the setParameter() method.

[vahidqaw]

Thank you very much for your reply. It was a great help. I would appropriate it if you could help me a little more. I am using the the Bilin material (Modified barra-Medina-Krawinkle deterioration model: "uniaxialMaterial Bilin $matTag $K0....") for plastic hinges. I need to update "$theta_p,$theta_u,$theta_pc , $My and $as" for plastic hinges. The material supports the setParameter() method, but I couldn't understand how to apply it. The command syntax in opensees is "parameter $tag <specific object arguments>". Do you know how to apply it for the Bilin material? Moreover,I am using the following element.
element forceBeamColumn $eleTag $iNode $jNode $transfTag "HingeRadau $secTagI $LpI $secTagJ $LpJ $secTagInterior
Once I have updated the uniaxial material, do I have to update anything for the above element as well? Thank you very much again.

[vahidqaw]

I am using the following commands for updating for updating the alfaCap value of element 1:
parameter 1 element 1 section 1 material 1 alfaCap
updateParameter 1 $value
I receive the following error:
"Parameter::addComponent 1 -- no objects were able to identify parameter "
Any ideas?

[fmk]

yes .. it did not find something valid to update in the parameter command that preceeded it.

[vahidqaw]

Thank you fmk. Then, we should conclude that the bi-linear material cannot be updated during the analysis?

[henryluo]

Hi, I’m using the addToParameter command to update the material parameters used for fiber section (concrete 01 and steel01). “No objects were able to identify parameter” also occurs. Does this mean that these two material models can not be updated? Could anyone give me some information about this issue? Thanks!