ETABS 2013 _AS1170.4 Response Spectrum
ETABS 2013 _AS1170.4 Response Spectrum
(OP)
Anyone using AS1170.4 response spectrum in ETABS 2013? Results I am getting is not convincing, about twice that of static calc.please coment.
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ETABS 2013 _AS1170.4 Response Spectrum
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RE: ETABS 2013 _AS1170.4 Response Spectrum
I'll forward this thread onto him.
RE: ETABS 2013 _AS1170.4 Response Spectrum
RE: ETABS 2013 _AS1170.4 Response Spectrum
Otherwise, check your units for the scaling factors for the Response Spectrum load case.
Also worth checking that the "comparison" case of Seismic loads (Auto lateral loads) is including the appropriate masses and live loads, and is assuming the same parameters as your response spectrum.
Ultimately you should get very similar results between the two analyses. The main benefit of the response spectrum is that it is independent of load direction and gives you a single "envelope" design case.
Finally, do a hand check to the code in addition to the above. ETABS can be the epitome of black-box technology if you are not careful with your checking.
RE: ETABS 2013 _AS1170.4 Response Spectrum
Did some hand checks this morning. Results look fine.I chose a bigger Time period for Equivalent Force Method which gave me low base shear. But still base shear from response spectrum is bigger than that obtained from ESA. That's why I was surprised at first because in all my previous projects response spectrum base shear came out to be lower. Since my hand calcs agree with this values I will take that.
Thanks.
RE: ETABS 2013 _AS1170.4 Response Spectrum
Check the 1st mode period using Rayleigh or similar method.