Update/Change section properties during analysis

[jayghosh]

Hi,

I have a fiber section column model (from the OpenSees examples) in which I want to change the reinforcement area in between a ground motion time history analysis.

The part of the code I am trying to modify is:

" section fiberSec $ColSecTag {; # Define the fiber section
patch quadr $IDconcU $nfZ $nfY -$coverY $coverZ -$coverY -$coverZ $coverY -$coverZ $coverY $coverZ; # Define the concrete patch
layer straight $IDreinf $numBarsCol $barAreaCol -$coreY $coreZ -$coreY -$coreZ; # top layer reinfocement
layer straight $IDreinf $numBarsCol $barAreaCol $coreY $coreZ $coreY -$coreZ; # bottom layer reinforcement
}; # end of fibersection definition"

What I am wanting to change/update is the $barAreaCol in between the analysis after a certain number of time steps of the ground motion. Can be represented as follows:

Make model with $barAreaCol = 1.0 --> Apply gravity and start time history for ground motion --> After time t (say 10 seconds) update $barAreaCol = 0.8 --> Continue and finish analysis. Any help would be appreciated. Thank you.

Jay

[fmk]

it is not something that can be updated at present .. if you want you could download the code, rename and then test it. the method you want to modify is modify the setParameter() method and add an updateParameter() method.

[jayghosh]

Thanks, Frank. If I understand correctly, I should recompile OpenSees after modifying the code and adding the setParameter() and updateParameter() methods. Should I be modifying the cpp code for only the "layer" command then?

I will follow the cpp files for RCSection2d (which I believe can be updated) and try to implement them. As follow up question, can I use the RCSection2d directly instead of trying to define my fiber section using the "section Fiber" command?

[jayghosh]

For everyone's reference:

I solved my problem using RCSection2d to build the fiber section column element. This section can be updated during the analysis. I wanted to update the reinforcement area of the top layer to model corrosion deterioration.

After defining my section and element as:

set RCSecTag 11; # Tag for RC Section
section RCSection2d $RCSecTag $IDconcU $IDconcU $IDreinf $coreY $coreZ $coverY $barAreaCol $barAreaCol $barAreaCol 12 4 $numBarsCol
element nonlinearBeamColumn 1 1 2 $numIntgrPts $RCSecTag $ColTransfTag; # self-explanatory when using variables

I defined the parameter for the top reinforcement as:

parameter 100 element 1 Atop

You can find other parameters you can change here: http://opensees.berkeley.edu/WebSVN/fil ... ration.cpp

Then within the analysis one can update the reinforcement area as:

set NewArea 2.25
updateParameter 100 $NewArea

[AnggaSetiawan]

Dear All

I do twice static cyclic analysis of 3 part fused of RC Column connected by friction devices (with twoNodeLink element), at 1st analysis I want to get only the DOF of the twoNodeLink element in direction 1, and before the second analysis I want to get the DOF to be in direction 1 and 2
Would you like to give me idea?

Thank you