BaseLine

[Jhno]

Hi, is there a way to do a baseline correction when refining the time steps or do I have to manually edit the time serie? Thanks!

[selimgunay]

Do you mean on the ground motion input? You need to do that externally somewhere else

[Jhno]

So that mean I cannot use the VariableTransient analysis and have to get a time serie as long as necessary to accomodate the smallest time steps of the dynamic problem??
That is time consuming..

[fmk]

the dt of the analysis and the steps in the Path times series do not have to be the same .. OpenSees just uses linear interpolation to get the timeseries value at whatever time the domain is at.

[Jhno]

Yes, I do understand this.
However, say I have a ts defined at timesteps of 0.002. I baseline correct it and then feed it to the algorithm and it produce the expected acceleration.
I do a linear interpolation from this ts to get a new ts defined at 0.001 and then I feed it to the algorithm without baseline correction.
I do get spurious acceleration (oscillation between + and - value). The more I refine the initial timeserie, the more I get this.
I guess it produce the same thing in OS as when I record my acc to the node where I prescribe the motion I see a similar pattern (good value when the baseline corrected ts timestep match the analysis timesteps, spurious value when the anaysis ts is smaller than the ts timesteps).
Maybe I made a mistake but I overchecked alot and I always end with that pattern =(

[selimgunay]

For clarification, could you post part of your code that is related to what you are doing