dt AccelSeries and Dtanalysis

[schoolstru]

the command
set AccelSeries "Series -dt $dt -filePath $EQ_NAME -factor $GMfact"; # time series information
defines the time-acceleration for dynamic analysis;
the command
set ok [analyze $Nsteps $DtAnalysis];
is conducted to analyze in step as $DtAnalysis
1- is it necessary that $dt==$DtAnalysis?
2- if we have $DtAnalysis<$dt (we intentionally small $DtAnalysis to get convergence) is it necessary to generate the acceleration series having $dt equal to $DtAnalysis? or not
in other words, does the OpenSees interpolate acceleration itself?
providing that $Nstep are adjusted according to this command
set Nsteps [expr int($TmaxAnalysis/$DtAnalysis)];
thanks

[Sudan]

Yes, you can use $DtAnalysis<$dt , for such case OpenSees will interpolate the missing value itself.

[parasismique]

Dears Sirs,

I am working on the vulnerability of bridges.
In the dynamic ground motion analysis, can we plot the curve of curvature of columns depending of the time?!!

So if you can helps me I will be very grateful.
Thank you in advance for your time and consideration.