Dear viewers here is the second part of the tutorial of example model. Up to this stage our model drawing is complete. Now we will apply the loads. For this first of all we have to define the loads our building may be subjected to.
1. First of all go to Define→Static load cases
2. The following window will appear. Dead and live loads are already defined. Click any one of them and edit.
3. Write the name of load like ‘SDEAD’ and select the load type that is ‘SUPER DEAD’. Then click ‘add new load’.
4. The load will be shown in the list. In the same way add ‘wind load’. In the ‘auto lateral load option select according to the code you are following. I have chosen ASCE 7-02.
5. When it has been added, highlight it and click ‘modify lateral load’. The following window will appear. Select ‘Exposure from Frame and Area Objects’. Change the wind speed according to the area where the building is located.
6. Now add Earthquake load in x direction. In ‘Auto Lateral Load’ select the code. Then click ‘Add New Load’.
7. Now highlight EQX load and click ‘Modify Lateral Load’. Provide details about Soil Profile Type and Seismic Zone Factor and other details.
8. When the loads have been defined, now you have to add the load combinations. For this go to Define→Load Combinations
9. 1st load combination which I have added is 1.2D+1.6L
10. In this way one by one add other combinations. Or you can also use default design combinations already present in the software. For this go to Define→Add default Design Combos
11. Now select the type of the building you are going to model. As we are modelling concrete structure so I have chosen Concrete Frame Design.
12. Now we have to apply loads to the slab. For this first select the slab, go to Select→By Wall/Slab/Deck Section
13. The following window appears. Choose Slab1 (we had already defined in Area Section).
14. All the slabs will be selected (don’t forget to choose ‘similar stories’ option at the bottom). Now go to Assign→Shell/Area Loads→Uniform
15. Enter the loads one by one following the same procedure as described below:
Select Load Case Name ‘SDEAD’, choose Units ‘lb-ft’ and then write down the magnitude of the load 30 or as specified.
In the same way first select the slab and apply wind load and other loads.
16. Next step is meshing of the slab. For this go to Assign→Shell/Area→Area Object Mesh Options
17. Auto Mesh Object into structural Elements and then check ‘Further Sub-divide Auto Mesh with Maximum Element size of 24’.
18. To view the meshing of the slab go to View→Set Building View Options and check the option for ‘Auto Area Mesh’ in Other Special Items.
19. Now the model will look like this.
20. Now we have to provide End Length Offsets for better connection of beams and columns. For this go to Select→By Frame Sections. All the Beams and Columns will be selected.
21. Now go to Assign→Frame/Line→End Length Offsets.
22. Select Automatic from Connectivity. Click ‘ok’.
23. Now we have to provide the restraints for columns. Go to the bottom storey and make a window selecting all the column foundations.
24. Now go to Assign→Joint/Point→Restraints (supports)
25. Select fixed restraints in the following window. Click ‘ok’.
26. Now your modeling is complete. Run the Analysis
Your structure’s deformed shape will be displayed. You can check the structure’s deflections under various applied loads one by one by playing the animation. You can also check the design by going to Design→Concrete frame design→Display design info
To see the complete 3D view go to View→Create Open GL View
Thats all for now. For any other instance you can consult a complete and comprehensive tutorial on Etabs. Keep visiting knowledgeoverflow for more.