Change value according to the results

[drowning6]

Dear everyone.

Can I change one value in my model with the result I got from every time step when I apply transient analysis like ground motion?

Thanks for all.

[fmk]

yes you could.

[mhscott]

If I may elaborate on fmk's correct, yet terse, response ... you can use the 'parameter' and 'updateParameter' commands to do what you ask.

[drowning6]

fmk and mhscott, thank you so much.

If I want to change the elastic modulus of material 16 of element 66, I should set

parameter 1 element 66 material 16 E

And then in the analysis part I set ,
set tFinal 90
set dT 0.005
set ok 0
set currentTime 0

while {$ok==0&&$currentTime<$tFinal} {
set currentTime [getTime]
set EE [expr $AA*$Ec/($Tr*(1+(3*pow(abs($currentDisp),2.0))/(pow($pi,2.0)*pow($rr,2.0))))]
updateParameter 1 EE

set ok [analyze 1 $dT]
}

Can I give the new EE(elastic modulus) to the material 16 of element 66 at every time step?

[drowning6]

And by the way, what I want to change is elastic uniaxial "Material" of zerolength "element".
Is this command still available?

thanks.

[fmk]

you cannot change the material, only the material property. and did you run the analysis and check that it did indeed change the response before you asked if you can???

[drowning6]

Thanks fmk.
Sorry, I mean the material property.
I can run the analysis successfully now.
The interesting thing is that if I set "parameter 1 element 66 material 16 E", Opensees says "unable to identify the parameter".
However, if I set "parameter 1 element 1 material 1 E", the analysis can run successfully.
Actually, I mean element 66 and element 1 is same element. And material 16 and material are also same.

Maybe if we define the parameter, the material or element must begin from No.1???

Anyway, thanks so much for your reply.

Have a great day.

[mhscott]

No, the elements dictate how they interpret the arguments for the parameter command. For a zero length element, the number that comes after material, e.g., ... material 1 ... indicates the first material defined for the element (2 would be the second, and so on). A fiber section in a beam-column element would interpret this as the material tag, but not so for a zero length element.

[drowning6]

Thank you Dr. Scott.

Very interesting.
For example, if I have the following commands.
element zeroLength 56 20 11120 -mat 20 -dir 1
element zeroLength 1 22 11122 -mat 6 -dir 1

The material 6 is the first material defined the zerolength element, is that right?

Thank you for you reply.

[mhscott]

Yes, but when you do the parameter command, you will still use 1

[drowning6]

Ok, thank you.