Load control vs Response control
Load control vs Response control
As far as i am concerned seismosoft suggests to use response control loading when using conventional force based pushover analysis (correct me if not). When using displacement based adaptive pushover analysis should i use adaptive load or response control option?
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Stelios_Antoniou
- Posts: 89
- Joined: 17 Jul 2011, 20:08
Re: Load control vs Response control
The main advantage of response control in pushover analysis is the ability to get the descending branch of the capacity curve (where the force descreases with increasing deformations).
With displacement based pushover, whereby you apply displacements, you can get the descending branch with either response or load control
With displacement based pushover, whereby you apply displacements, you can get the descending branch with either response or load control
Re: Load control vs Response control
Antoniou
I model 2D RC frame in Seismostruct V.6 and I want to calculate yield force and yield displacement of frame, I pushover it and I bilinear the capacity curve respect to FEMA356 rules. but I have problem with loading phases and load pattern I use displacement rather than force.when I change uniform to triangular or adaptive the yield force and yield displacement are so changing. And also when I change load control to response control also I encounter with huge changing. When I use load control or scheme of load control with automatic control frame push until 0.9m and its yield displacement obtain 0.08m although target displacement(according coefficient method) is 0.09m! and I read in forum that I cant use adaptive with automatic response control(only scheme that give me resonable results) I was baffled which loading phase is the best for calculating yield force & displacement ,according FEMA it should be between 0.01-0.04m
I model 2D RC frame in Seismostruct V.6 and I want to calculate yield force and yield displacement of frame, I pushover it and I bilinear the capacity curve respect to FEMA356 rules. but I have problem with loading phases and load pattern I use displacement rather than force.when I change uniform to triangular or adaptive the yield force and yield displacement are so changing. And also when I change load control to response control also I encounter with huge changing. When I use load control or scheme of load control with automatic control frame push until 0.9m and its yield displacement obtain 0.08m although target displacement(according coefficient method) is 0.09m! and I read in forum that I cant use adaptive with automatic response control(only scheme that give me resonable results) I was baffled which loading phase is the best for calculating yield force & displacement ,according FEMA it should be between 0.01-0.04m
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seismosoft
- Posts: 1263
- Joined: 06 Jul 2007, 04:55
Re: Load control vs Response control
bshad,
We are not sure we understand your problem, but would simply like to note that we recommend the use of 'response control' with Displacement-based Adaptive Pushover.
Seismosoft Support
We are not sure we understand your problem, but would simply like to note that we recommend the use of 'response control' with Displacement-based Adaptive Pushover.
Seismosoft Support
Re: Load control vs Response control
Seismosoft
when I use 'response control' with Displacement-based Adaptive Pushover
Yield Displacement is obtained 0.07m!(Yield force: 630KN) and total height of my frame is 12m and software push frame till 0.6m without any descending,
when I use 'Automatic response control' with uniform load pattern Yield Displacement is 0.017m (Yield force: 866KN) and I think this is reasonable.but they are so difference
and Question is: what kind of Element classes is better for displacement-based pushover(Adaptive or triangular conventionally) InfrmFB or InfrmDB they have so different results
when I use 'response control' with Displacement-based Adaptive Pushover
Yield Displacement is obtained 0.07m!(Yield force: 630KN) and total height of my frame is 12m and software push frame till 0.6m without any descending,
when I use 'Automatic response control' with uniform load pattern Yield Displacement is 0.017m (Yield force: 866KN) and I think this is reasonable.but they are so difference
and Question is: what kind of Element classes is better for displacement-based pushover(Adaptive or triangular conventionally) InfrmFB or InfrmDB they have so different results
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seismosoft
- Posts: 1263
- Joined: 06 Jul 2007, 04:55
Re: Load control vs Response control
bshad,
There is no general response that applies to all possible cases, and it might well happen that some times one obtains better results using a modelling approach that is different from the generally recommended one.
For what concerns your question on recommended frame element type, infrmFB does tend to be superior, for the reasons discussed in the literature (see some of the bibliography cited in the Help System/User Manual), but, again, this does not necessarily apply to all and every single case.
Seismosoft Support
There is no general response that applies to all possible cases, and it might well happen that some times one obtains better results using a modelling approach that is different from the generally recommended one.
For what concerns your question on recommended frame element type, infrmFB does tend to be superior, for the reasons discussed in the literature (see some of the bibliography cited in the Help System/User Manual), but, again, this does not necessarily apply to all and every single case.
Seismosoft Support