Project 2 - MODELLING, ANALYSIS & DESIGN OF COMPOSITE STUCTURES IN COMFLOR & ETABS

Answer of the Question :1

Key Highlights:

a. Modelling

• The structural model prepared for the project 1to be used for the project 2.
• Prepare two distinct structural framing plans (location of primary & secondary beams) as discussed in Lecture 11.
• Create member definition for the steel sections by importing through library.
• Select deck slab profile and section using the Comflor Manual.
• Modelling of the composite metal deck section in ETABS
• Modelling of the composite columns in ETABS
• Create steel beam, steel column, bracing & core wall properties to be used further in the project.

b. Loadings & Load combinations

• Comflor: Wet concrete and construction loads for the design of deck slab
• ETABS: Use load patterns and combinations created in project 1
• Definition of Pre-composite dead loads
• Define footfall loadings for the vibration checks.

c. Structural Analysis

• Comflor software to be used for the analysis of composite deck slab
• Obtain the shear force & bending moment diagrams for the floor beams and columns.
• Check the gravity load path in the structure if it follows the designer’s intent.
• Perform quick hand calculations to confirm the base reactions for the gravity load cases.
• Check natural frequency for the floor system and mitigate the floor vibration by keeping fundamental frequency > 3Hz.

d. Design of structural members

• Shear studs & Composite deck design calculations
• Interpretation of the design results for the composite beam from ETABS
• Pre-camber criteria and requirements

Key Deliverables:

• Comflor file with the complete modeling of the slab with appropriate loadings
• Comflor report for the composite slab design (as PDF file)
• Submit a ETABS model with the complete model of the composite structure.
• A comprehensive project report from the ETABS software (as PDF file)

Answer:

• Import the architectural floor plan (provided by the architect) in ETABS model to start with the modelling:

- In order to import the architectural floor plan which is provided by the architect in ETABS model,go to the AutoCAD software,open the model in the AutoCAD and then save as the file in the dxf. format just as shown in the below given image:

Now safe the file in the dwg.form and then quit the AutoCAD software just as shown in the below given image:

• Create grid lines, story levels & story heights to set-up a project:

- And after that there will be another dialouge box, where we will be given the details regarding the stories,grids etc just as shown in the below given image:

After clicking on the Import there will be another drop-down list and in that list there will be another option called .dxf file of the floor plan just click on that option just as shown in the below given image:

After clicking the material properties then there will be another dialouge box there will be another dialouge box named as the Define materials and in that dialouge box there will be an option called Add New Material just as shown in the below given image:

Beam(400X500):

- So first of all we will be defining the beam,so in order to assign the beam first we will be clicking on the Define option after clicking on the define option there will be a drop-down list and in that list there will be another option section properties.

- After clicking the section properties there will be another drop-down list and in that drop-down list there will be another option called Frame section just click on that option just as shown in the below given image:

And after clicking on the Add New Property there will be another dialouge box named as the Frame Property Shape Type and in that dialouge box there will be an option called Rectangular Concrete and then click OK just as shown in the below given image:

Then there is another option named as the Modift/Show Rebar just click on that option then there will be another dialouge box named as the Frame Section Property Reinforcement Data

-after that there will be another option Modify/Show Modifiers just click on the option.

Column(500X500):

- So now we will be assigning the columns for this project.

- So first of all we will be defining the column,so in order to assign the column first we will be clicking on the Define option after clicking on the define option there will be a drop-down list and in that list there will be another option section properties.

-

- So now we will be assigning the columns for this project.

- So first of all we will be defining the column,so in order to assign the column first we will be clicking on the Define option after clicking on the define option there will be a drop-down list and in that list there will be another option section properties.

- After clicking the section properties there will be another drop-down list and in that drop-down list there will be another option called Frame section just click on that option just as shown in the below given image:

SLAB(150):

- So now we will be assigning the slab for this project.

- So first of all we will be defining the slab,so in order to assign the slab first we will be clicking on the Define option after clicking on the define option there will be a drop-down list and in that list there will be another option section properties.

- After clicking the section properties there will be another drop-down list and in that drop-down list there will be another option called Slab Sections just click on that option just as shown in the below given image:

after clicking on the Add New Property there will be another dialouge box named as the Slab Property Data and in that dialouge box there will be other options fill the necessary details as shown below and then click OK just as shown in the below given image:

WALL(250):

in order to assign the wall property,first go to the option Define click on that option then there will be a drop-down list and in that drop-down list there will be an option called Section properties and then there will be another drop-down list and in that list there will be another option called Wall Section just click on that option just as shown in the below given image:

WALL(150):

in order to assign the wall property,first go to the option Define click on that option then there will be a drop-down list and in that drop-down list there will be an option called Section properties and then there will be another drop-down list and in that list there will be another option called Wall Section just click on that option just as shown in the below given image:

Now we have defined the all properties and now we need to place the all components in the project in ETABS just as shown in the below given image:

BEAM:

b. Loadings & Load combinations:

• Define load patterns for gravity cases.
• Define load patterns for the lateral load cases using the wind & seismic parameters provided.
• Create service & ultimate load combinations as per IS 456:2000.
• Define mass source for the earthquake loads.

• Define load patterns for gravity cases:

- Now we will be defining the load patterns for the gravity cases.

- So in order to define the load patterns,first go to the define option then there will be a drop-down list and in that list there will be an option called Define just click on that option.

- After clicking on that option there will be another drop-down list and in that list there will be another option called Load Patterns just click on that option just as shown in the below given image:

• Define load patterns for the lateral load cases using the wind & seismic parameters provided:

- Now we will be assigning the load patterns for the lateral load cases using the wind and the seismic parameters provided.

- For the wind load we will be considering the Chennai as the location for our building:

Basic Wind Speed - 50m/s.

Terrain Category - 3

k1 - 1

k2 - 1.105

k3 - 1

k4 - 1

- So in order to assign the load patterns,we will be going to the option Define just click on the define option and then there will be another drop-down list and in that list there will be an option named as the load patterns just click on that option just as shown in the below given image:

For EQY+:

For EQY-:

- After this,now we will be assigning these loads in the software.

- And to assign these loads,go to the Assign option just click on that option,after clicking on that option there will be a drop-down list and in that list there will be an option named as the Frame Loads click on that option and after that there will be another drop-down list named as the Distributed again click on that option just as shown in the below given image:

- And we know according to the IS code 875:Part2:

• Live load - 2 kN/sq.m.
• Brickwall load - 3.5 kN/m.
• Floor Finishes - 1.5 kN/sq.m.
• Parapet wall - 1 kN/m

- And after clicking on the option there will be another dialouge box named as the Frame Load Assignment-Distributed and in that dialouge box fill out the all necessary details just as shown in the below given image:

- Below is the 3-D image of the building after assgning the Brickwall loads just as shown in the below given image:

So in order to assign the Live Load,just go to the assign option click on that option then there will be a drop-down list and in that list there will be an option called Shell Loads just click on that option after that there wll be another drop-down list and in that list there will be another option called Uniform just click on that option just as shown in the below given image:

-D image of the building after assgning the Brickwall loads just as shown in the below given image:

clicking on the Mass source option there will be a dialouge box named as the Mass Source and in that dialouge box there will be an option called Modify/Show Mass Source just click on that option just as shown in the below given image:

After assigning the modal cases we will be defining the Response Spectrum function.

- And in order to assign the response spectrum function,go to the Define tab click on the Define option then there will be a drop-down list and in that list there will be an option called Functions click on that option after that there will be another drop-down list and in that list there will be another option called Response Spectrum click on that option just as shown in the below given image:

- After this there will be another dialouge box named as the Define Response Spectrum Functions and in that dialouge box there will be another option called Add New Function just click on that option just as showsn in the below given image:

- After this there will be another dialouge box named as the Response Spectrum Function Definition-IS 1893:2016 and fill out the all necessary details just as shown in the below given image:

- And now add Response spectrum in load cases as RSx and RSy.

- And in order to assign the response spectrum just go to the Define tab click on that option then there will be a drop-down list and in that list there will be an option called Load Cases click on that option just as shown in the below given image:

in order to assign the diaphragm,we need to go to the Assign tab click on that option and then there will be a drop-down list and in that list there will be an option called Shell click on that option after that there will be another drop-down list and in that list there will be another option called Diaphragms just click on that option just as shown in the below given image:

And now we have to assign the the service and the ultimate load combinations as per the IS 456:2000.

- So, in order to assign the load combinations just go to the Define tab click on that option then there will be a drop-down list and in that list there will be another option named as the Load combinations click on that option too just as shown in the below given image: