Hi,seismosoft
I want Calculated ductility for elasto-perfectly plastic system under ground motion.
ductility= Umax/Uy
How it calculated by seismosignal?
ductility
Re: ductility
As per the Help System within the "Elastic and Inelastic Response Spectra" subtopic, the Newmark integration scheme is used to solve the inelastic system. As noted in the Help System, the parameters beta and gamma affect the solution, and definition of the post-yield stiffness ratio is required.
For elastic-perfectly-plastic (EPP) behavior, the post-yield stiffness ratio should be changed from the default value of 0.02 to 0.0.
Note that SeismoSignal produces constant-ductility inelastic spectra. So if you have a particular structure for which you wish to know the resulting ductility factor when subjected to a particular ground motion record, a very simple SeismoStruct model may be the better option.
For elastic-perfectly-plastic (EPP) behavior, the post-yield stiffness ratio should be changed from the default value of 0.02 to 0.0.
Note that SeismoSignal produces constant-ductility inelastic spectra. So if you have a particular structure for which you wish to know the resulting ductility factor when subjected to a particular ground motion record, a very simple SeismoStruct model may be the better option.
Tim Huff
Re: ductility
Dear huffte,tank you for help.i want plot ductility factor-time(ductility spectra) for 4 grouand motion .use seismostruct for all time is very difficult.
Re: ductility
I’ll try again bakhtiyar.
I’m not certain what you truly intend by the phrases “ductility factor-time” and “ductility spectra”.
To plot ductility demand versus time for a given record, you could simply take the SeismoStruct displacement history and divide all the values by the yield displacement, so it would have the same shape as the displacement history, but would be normalized by the yield value.
For a given ductility value and initial period, SeismoSignal will give you the displacement history - see the “Response Time Histories” sub-tab within the “Elastic/Inelastic Response Spectra” tab.
Or perhaps you want to find “constant strength” inelastic spectra as opposed to “constant ductility” inelastic spectra? In this case, I do not believe that SeismoSignal will do that easily - the only option is “constant ductility” inelastic spectra.
I’m not certain what you truly intend by the phrases “ductility factor-time” and “ductility spectra”.
To plot ductility demand versus time for a given record, you could simply take the SeismoStruct displacement history and divide all the values by the yield displacement, so it would have the same shape as the displacement history, but would be normalized by the yield value.
For a given ductility value and initial period, SeismoSignal will give you the displacement history - see the “Response Time Histories” sub-tab within the “Elastic/Inelastic Response Spectra” tab.
Or perhaps you want to find “constant strength” inelastic spectra as opposed to “constant ductility” inelastic spectra? In this case, I do not believe that SeismoSignal will do that easily - the only option is “constant ductility” inelastic spectra.
Tim Huff
Re: ductility
tanks. I try Calculated maximum displacement history divide yield displacement for "SDOF" structure Has a Natural period (0.02 to 4)s.