Random excitation

[sanazzz]

Is there any way to apply f(t) (random input) at the base of the model?
I know we can apply timehistory using file but I am wondering if there is a way to apply a function which reads the deltaT from the input code and then apply the f(t) at the model.

Thanks

[fmk]

if you can write it in tcl you could do it.

[sanazzz]

Imagine that I can write it in tcl but how OpenSees understands that? How should I code it so that Opensees understands?

There are certain ways to apply an excitation ( e.g. plain ... )

Thanks

[armkam]

I think the following youtube video from PEER channel can be useful:
https://www.youtube.com/watch?v=o5V_p9kHbrA

[sanazzz]

Thanks.
I think this video is useful for adding something to the main code, I am looking for something simpler.

[fmk]

i take it you can write the tcl code to determine the displacement you want to impose at each step.

if so you have a number of options:
1) write the data to a file, create a ground motion using the file and impose this on the model inside a MultipleSupportMotion
2) create a loop and inside create a load pattern, inside it put a sp constraint with the value for that step, perform an analysis step and then remove the load pattern

[sanazzz]

Thanks for your response.
But how can I loop over time?
Can you write a simple schematic code in order to do that? Should the analysis section be in the loop?

Bests