
Hi edward,
You've done a great work. was very surprised. Thank you very much. I now understand more clearly what they want to say.nobody could tell that so well. into the hands of health care.
about robot model.
1 my question is floor analiz method is rigid diaphram or only shell?
2 in our seismic standart have a criteria for peryot. N= number story of building
peryot not greater than Tx,Ty < 0.1N ( sample number story 40 then T max = 4 second.) this criteria at UBC yet? and why your bulding restraint simple restraint, not fixed. if fixed this base nodes then your period itself will decrease.
and you are lucky mans. cuz your code and standart exist in Robot and etabs. We are assigning for static lateral load shell is rigid. we are doing rigidity center lateral load. with hands calculate and define value for fx,fy. look we areuse turkish standart but not exist etabs and robot these. :/
many many thanks
falconado_turkey
Last edited by troy_the.best; 20100825 at 09:35 PM.
dear brother,
I want to say a few things.
first ..
we use scale factor in units ton.meter., but your definition is kip.in. is it mistake?
second...
we doing seismic loads analysis, if Vspec > Vstatic never reduce scale factor. because it will be wrong. but seismic (response analysis) are essentially. therefore we cant response spectrum scale factor in etabs and other programs. why do you this reduce? i m not understand, brother. is it right?
see later
best regards
falconado_turkey
See,
when you open Etabs by default units will be kpi and you have to change to KNM
when we run the model as a first time we put an accelarion of Spectrum diagram 9.81 m/s2
you can select any value you can put 1 2 or 3 as you want
We will say this is first scale factor Say FS1 ok
when we run analysis and we will know the natural period of building then we can get a static shear force
simply static shear force means the building is rigid i.e the the full energy of seismic will transfere to the building ok
Last step we have to callibrate the accelarion of seismic for response spec
this is what we say scale Factor
so the dinal scale factor of response diagram say SF2= SF1 x Vstatic/Vdyanmic
ok
But now you will be confiused and you ask how Vstatic< vdynaimc
it is not like that just we adjust the accelarion of spectrum curve
you get my point
Hoping it is clear
edward,
if Vspec > Vstatic ( Vspec too large then Vstatic) then probably a mistake your model or specrtum analysis. values are usually very close. Please pay attention to this point. Have very different results, if the model is broken or not stabil. and dont reduce spec factor (if Vspec is great) absolutely. I know this very well.. please check again this point edward. usually spectrum analysis is essentialy in our solutions. equal lateral static loads for comparison. and have any period restrictions in your Code.
To use this equation. SF2= SF1 x Vstatic/Vdyanmic (have to be Vstatic>Vspec)
sorry my english.
best regards
falconado_turkey
Last edited by troy_the.best; 20100826 at 06:27 AM.
hi friends,
i have a question. please look this screenshoot. whats the mean main mode number in seismic case.?
thanks in advice.
regards.
falconado_turkey
A.S.C.
troy_the.best,
Run modal analysis, then go to ResultsAdvancedModal Analysis. Look at columns name as Cur.mass UX, UY & UZ. Find maximum value in each column and look at number of mode for this value. And now you have main modes for X, Y & Z direction! Just type it in Combination Sign menu (your screenshot).