Click a blank cell in the grid table say row 5, column 1 to update the pictorial display of the grid. The result should look like the figure. Click the OK button. We do not need to change the Y grid spacing. Set Story Dimensions Next we define the vertical dimensions of the building.
Note: 2. Click a blank cell in the table to update all values. Click the OK button to close the form. Add Structural Objects So far we have only laid out a grid in the vertical and plan di- mensions. Now we will add the beams, columns, and steel decks. These objects are the starting point for the model; we will some make changes later: Continuing to work in the Building Plan Grid System and Story Data Definition form: 1.
This opens the Steel Floor System form. This is the distance the floor extends beyond the perimeter grid lines. Using zero will simplify our model, and this is recommended for small values of overhang to help avoid poor aspect ratios in your slab mesh. We will not add any additional floor load to this case.
Later we will create a new load case to handle superimposed dead load for compos- ite-floor design. Initially it has zero load in it.
This indicates that all columns and beams ex- cept the secondary beams contribute to the lateral-force- resisting system. This will create a constraint at each floor level so that the floor moves horizontally as a rigid body, and will be needed to use automated seismic loads with ec- centricity. Lastly, we define the Structural System Properties to be used by the different structural objects.
You may select from properties that are predefined by the program. You always have the option of modifying and adding to these property definitions. This is a set of steel sections, called an auto select section list, to be used for the columns of the lateral-force-resisting system.
The program will select the optimum members from this set during steel frame design. We will examine the defini- tion of this auto select section list later. This defines an auto select section list to be used for the beams of the lateral- force-resisting system. This defines an auto select section list to be used for the secondary beams of the flooring system from which the program will select the optimum members during design.
Note that this is a single property, not a set of multiple properties. Auto select section lists are only available for steel members. When you are done, the Steel Floor System form should look like the figure above. Two views of the structure should now appear, as shown in the figure below. We have completed the initial definition of the structural model.
Because it is the model often. This is a standard Windows file-saving sionally save a form. Using standard Windows operations, select the folder where with a different you want to save this file.
Then enter a file name, such as name. Click the Save button. This saves the file and closes the form. You may do this again at any point later in the tutorial if you need to take a break: 1. If you had made any changes since the last time you saved the model, you would be given a chance to save your model before the program is closed.
This opens the standard Windows file-opening form. Click the Open button. We are now ready to continue. Tip: Only one view can be active at a time.
You can change the active view by clicking the title bar of the desired window. The title bar You can change will then be highlighted. Any changes made to viewing options the active view by clicking will only affect the active view. Click the title bar of the left window to make sure the plan want to make active, or by view is active. Notice that a bounding rectangle is shown in clicking in the the 3-D view showing which floor is displayed in the active window itself.
Clicking on the title bar avoids 2. Move the mouse around in this view. Notice how the coordi- accidentally nates of the mouse are shown on the status bar at the bottom selecting of the main ETABS window.
On the top toolbar, click the Move Down in List button, window. Note how the bounding rectangle changes in the 3-D view to the right. Clicking the Move Up in List button, , reverses this process. Note: 7. Click the Perspective Toggle button, , on the top toolbar See the subsec- to toggle between a perspective view based on the chosen tion titled elevation and back to the 2-D elevation view. Notice that the bounding rectangle disappears.
Manual for additional in- 9. On the top toolbar, click the Set Building View Options formation. This opens the Set Building View Options form. Note: Under Special Effects, check the Extrusion box so that we can see the actual shape of the beam and column sections. Each of the options avail- Options form is discussed in the Click OK. However, they actually ex- Chapter 10 of tend to the column centerlines.
Click the Rotate 3D View button, , on the top toolbar. Then move the mouse cursor into the right window, click and hold the left mouse button while moving it around the screen. When you release the mouse button, the structure will redraw. To rotate again, you must click the button again.
See the figure above. Click the Clear Selec- Tip: tion button, , on the left toolbar to cancel this selection. You can also use the aerial view to zoom in Click the Rubber Band Zoom button, , on your model. Manual for more informa- Important: Again, if you drag the mouse like this without tion.
Click the Clear Selection button, , on the left toolbar to cancel this selection. To move around the neighborhood of the zoomed-in area, click the Pan button, , on the top toolbar. Then move the mouse cursor into the right window somewhere near the center. Click and hold down the left button while dragging the mouse around to pan the view.
Notice that there is a limit Note: to how far you can pan. Once you release the mouse button, See the subsec- you are no longer in pan mode. The first click undoes the Manual for pan operation. Click the button again to draw the full struc- additional in- ture. To return to the original 3-D view, click the 3D View button,. For what we will do later, we want to see the floors in the extruded view. All of the viewing actions we have performed here using buttons on the top toolbar can also be accessed from the View menu.
Additional viewing features are also available from this menu. Define Material Properties Default material properties are already defined for steel and con- crete. The material has been selected to be isotropic. These proper- ties are: The mass per unit volume used for dynamic analy- sis. The weight per unit volume used for self-weight gravity loading. The coefficient of thermal expansion used for ther- mal loading.
The choices are Concrete, Steel, and None. These data generally do not affect the behavior of the structure under load. For concrete, these properties are: The specified compressive strength of the concrete. The yield stress of the bending reinforcing steel. The yield stress of the shear reinforcing steel. An option to specify a shear-strength reduction fac- tor for lightweight concrete.
Since we are not changing anything, click the Cancel button to return to the Define Materials form. The minimum ultimate tensile stress. The cost per unit weight, which is used for compos- ite beam design. Click the Cancel button to close the Define Materials form.
You can use the Define Materials form to define one or more new material defi- nitions with the desired properties. Define Frame Sections Frame sections are named combinations of material and geomet- ric cross-sectional properties that can be assigned to beams, col- umns, and other line objects.
There are many different types of frame section properties that can be defined. You will see that a large number of predefined section properties already exist. More can be added. This is a wide-flange type of section. Note that the section has two local axes, axis 2 being the major axis, and axis 3 being the minor axis.
We will not change them. This shows the geometric section prop- erties calculated from the given dimensions. After re- Note: viewing this form, click OK to close it. See the sections 3. This property is called an auto selection section list.
The two scroll boxes together list all the individual sections that are currently defined for this model that use a material specified for steel design. In the box on the right, labeled Auto Selections, are the sections included in this auto selec- tion section list.
Scroll through the Auto Selections on the right to see the sections available for the columns. Click the Cancel button to close this form and return to the Define Frame Properties form. This opens the Auto Selection Sections form. This selects all the W10 and W12 sections. Click the Add button, which moves the selected sections to the Auto Selections box. We are now going to remove the smaller sections from this list.
Scroll down slightly. Chapter 4 of Four sections should now be selected. Click the Remove button. There should now be eight sec- ple items in list tions in the Auto Selections box.
The form should look like boxes. Define Deck Section Deck sections are named combinations of material and geometric cross-sectional properties that can be assigned to area objects. Note: We will take a quick look at the default deck section that we are Typically deck using, but not make any changes. Re- call that this is the property we specified for the floor when we started this model.
There is a lot of data specified on this form. Click Cancel to close the Deck Section form. Define Wall Section Wall sections are named combinations of material and geometric cross-sectional properties that can be assigned to area objects. Typically you assign wall sections to wall area objects. This form is considerably simpler than the floor for additional form. We will now create a second wall section definition.
Normally these two values should be the same. Leave the Type set to Shell and click OK to close the form. You can add as many static-load cases as you want. We will now create five more cases, one to represent additional dead load, and four to represent code-defined seismic lateral loads: Tip: 1.
You should typically only 2. Manual for more informa- 4. This is superimposed dead load, which is a special type for composite floor design. For other types of design, it will be treated simply as additional dead load. Click the Add New Load button to actually create the new load case and add it to the table. We will use this default. This is the appropriate factor for ordinary moment-re- sisting frames, which we will consider for our design. Review the rest of the form. We are not going to make any further changes.
Click OK to close the form. This gives us four seismic cases in all, two in each lateral horizontal direction, with two different signs of eccentricity. It should look like the figure above. Click OK to accept the new load case definitions and close the form. Because the model has been saved before, the file is saved without any further action from you. Here we will create the setback and add bracing and shear walls to the first story.
Delete Objects We are going to create the setback by deleting some beams and columns from the upper stories, and then modifying the floor area to fit the reduced size of the upper stories.
For now, the operation we will be performing is deleting selected objects. Make sure the right display window shows an extruded 3-D view of the structure, with all objects visible. Click the title bar of the left window to make that view ac- tive. Note: 4. Move the mouse cursor very slowly over the model in the left window.
Now move the mouse cursor along the beams, and note the complete de- presence of points where the secondary beams frame in, scription of the even though they can not be seen in this view.
Our selection operation will be easier without the snap fea- ture. Click the Snap to Points button, , on the left tool- bar to turn it off. Tip: 7. There are many ways to select You must select objects. The twelve members should show as dashed, indicating that they have been selected. This is also indicated in the 3-D view to the right.
The selection of these points will not affect our upcoming operation. Verify your selection by checking the message in the status bar at the lower left corner of the main ETABS window. If it says anything else, click the Clear Selection button, , on the left tool- bar, and try Step 7 again.
It is a good habit to check this message every time you make a selection. As each object is clicked, the image should become dashed, indicating that it has been selected. If it says anything else, click the Clear Selection button, , on the left toolbar, and try Steps 7 and 9 again.
Now that we have our selection, we are ready to perform the operation. This removes the objects from the model. Note that the deleted members disappear from both display Note: windows.
The Undo fea- ture works for Suppose we had made a mistake. Observe that the deleted objects reappear. Suppose we had not made a mistake. It does not work Redo command from the menus or click the Redo button, for the Define , on the top toolbar. Observe that the previously se- menu items and lected objects are deleted again. The model is back to where the Edit Grid it was at the end of Step In general, you can redo all op- and Edit Story erations that you undo. However, it is important to note that when working on plan views, selection can affect one or more stories, subject to your control.
Tip: See the figure below. The do not remain dotted line that appears while dragging the mouse should in the inter- cross all nine beams in the left bay. The nine beam objects intersecting line should show as dashed, indicating that they have been selection. If it says anything else, click the Clear Selec- tion button, , on the left toolbar, and try this step again. We must now deselect the floor area.
Move the mouse in the plan view to any point surrounded by four beams, but away See Chapter 13 from the beams themselves or the corners. The dashed line around the floor should dis- information on appear as it is deselected. If you accidentally select or deselect the wrong object, click objects. This removes the selected objects from the model. We have now removed the beams and columns from the setback, but the floors still stick out. We will remedy that next.
Reshape the Floors We will now modify the upper floors so that they are only as large as the right two bays. We will use the reshaper tool, which is very powerful but somewhat subtle. We will need to use the snap feature to assure accuracy for our next operation. Click the Snap to Points button, , on the left toolbar.
Verify that it is working by moving the mouse cursor very slowly over the model. In the plan view on the left, move the mouse to a point on the floor but away from beams and corners. Click the left mouse button. If this does not happen, click on a blank spot in the left window but outside of the structure, and then try Steps 4 and 5 again.
The cursor should change to a pair of crosshairs. Click and hold down the left mouse button. Tip: 8. Release the mouse button. The floor area should appear trapezoidal in the plan view on the left. This is shown in the Instead of figure above. The 3-D view on the right will not show the re- dragging the handle to its sults of this operation.
This completes our reshaping of the three upper handle and then floors. Click the Pointer button, , on the left toolbar to end re- it in the result- shape mode and return to selection mode.
Click the title bar of the right window to make it active, then click the Refresh Window button, , on the top toolbar to draw the new extruded view, as shown in the figure below.
This completes the modeling of the setback. This should already show the folder where we saved the first file. If not, select the folder where you want to save this file. Draw Braces We are now going to add braces at the bottom story level in the Y direction: 1. Click the title bar of the left window to make it active. ETABS program in steel and concrete frame design criteria for seismic design of buildings are all considered. The program will be based on the criteria of plasticity concrete frame and average ordinary and special design.
Steel buildings are also special rules of ordinary and special moment frames and braced systems converge and diverge in terms of the design.
In addition to the analysis and design is extraordinary, full two-way communication program ETABS software other more. To browse Academia. Log in with Facebook Log in with Google. Remember me on this computer. Enter the email address you signed up with and we'll email you a reset link. Need an account? Click here to sign up. Download Free PDF.
Abdul Raheem Raheem. A short summary of this paper. Download Download PDF. Translate PDF. Patel A step-by-step procedure for modeling and analysis of frame structure using ETABS is explained through a simple example.
Subsequently an example of seismic analysis of regular frame structure and irregular frame structure are solved manually and through ETABS. Set the grid line and spacing between two grid lines. Live load or any other define load 1st select the member where assign this load than click the assign button. For that, all slabs are selected first and apply diaphragm action for rigid or semi rigid condition.
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