Seismosoft | Earthquake Engineering Solutions

Dear All,
Is there any way I can get the residual drift by doing static pushover analysis? If anyone knows how to do that please let me know.
Regards
Amy

Hi amy. I am not really sure what you mean by 'residual drift' from a static pushover analysis, which gradually increases the loading to collapse.

It could be that a pushover with response control, with the target displacement specified large enough to reduce the final loading factor to nearly zero, would give a final residual displacement profile from which drifts could be estimated. The key would be to use response control, or possibly automatic control, as opposed to force control.

Note also that residual displacements, and thus drifts, would be readily available from a dynamic time history analysis with inelastic elements. You would want to plot the desired displacement versus time and capture the residual as such at the end of the time history. Note that it may sometimes be necessary to pad the end of the loading record with some seconds of zeroes in order to get the analysis to run long enough to converge on a true residual displacement.

In this latter case, the residual displacements are, of course, dependent upon the accelerogram used to load the structure.

If none of this helps, amy, perhaps you could elaborate a bit on your desired strategy.

Best of luck.

Thanks a lot Sir for your advice. Actually I want to do a static push over analysis with response control for a target displacement as you said. After that I want to fully unload the structure to determine the residual strain/deformation. I am not sure whether I can do it or not.
If it's not possible than I will do the time history analysis as you said.
Again thanks for your assistance. I really appreciate this.
Regards
Amy

Hi Amy,

What you can do is to apply a pushover analysis with two phases:
(1) in the first apply a typical response-control scheme
(2) in the second apply a force-control scheme with a target load factor equal to zero (the program does not accept a zero value, hence apply a load factor=0.000000001
After second phase, you will get the permanent displacement you want

SeismoSoft Support

Great strategy, seismosoft. I tried it and it worked like a charm. Hopefully you will find equally satisfactory results amy.

Thanks a lot. It solves my problems..