Download ETABS Tutorial With NBCCResponse Spectrum Case PDF

TitleETABS Tutorial With NBCCResponse Spectrum Case
File Size6.8 MB
Total Pages120
Document Text Contents
Page 1

This tutorial will take you through the steps necessary to model, analyze, and design a 4
story steel moment frame building with composite beam floors, a common application for

Page 2

To begin, click the ‘New model’ button or File>New Model and you will see
an option to choose an “.edb” file. With ETABS, you can open a model
based on the defaults of a previous model in order to access previously
defined load combos, sections, etc. But for this exercise, press No

Page 60

In plan view, window select the entire model as shown below left, then Assign>Shell/area
loads>uniform and type 60psf for LIVE load case and press ok

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Next, click once in the 3D window to make it the active window, then click ‘Set building view options and
turn off the extrusion view by un-checking the Extrusion box. Next, analyze the model Analyze>Run
analysis. After the analysis completes, click the ‘Show member forces/stress’ button shown below, click
Frame/Pier/Spandrel forces, then change Load to ‘Live’ and Moment 3-3 which is major moment

Page 119

Here you can give the function a name and input other parameters associated with the
NBCC2005 code for your particular site location. As you can see, the response spectrum
function is just time period vs Acceleration. For this example, we will just accept the
defaults by pressing OK, then pressing OK again.

Page 120

Next, Define>Response spectrum cases and click ‘Add new Spectrum’ button. Give it a name and specify direction and
magnitude which is scaled to G in current units. Let’s assume that we need to scale response spectrum loads to .2 G in order
to match with the static equivalent seismic base shear. If the units were Kip-ft, 6.44 scale factor is .2 G. Apply an eccentricity
factor of 5% (.05). If we were in Kip-in, we would input 77.2 scale factor if we wanted to scaled down to .2 G using inches.
Unless the support points have had their local axis rotated, U1 = Global X, U2 = Global Y, and U3 = Global Z. There is an
option to specify different eccentricities at each different diaphragm level. Input values as shown and press OK. Press ‘Add
New Spectrum’ button again and add another response spectrum case for U2 Y direction scaled to .2 G in current units.
Press OK and OK again. We’ve defined two response spectrum cases with eccentricity. You will have to modify your load
combinations to account for these seismic cases.

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