Week 8 Challenge

Solution.1)

Aim: To apply the load for the structure modelled in previous exercise.

• Form a Load case as DL for Dead Load
• Apply Self weight
• Apply member load of 3 kN/m on the rafter
• Apply member load of 6 kN/m on the secondary beams
• Apply point load of 20 kN at node intersecting inclined member on the top chord.
• Form a Load case as LL for Live Load
• Apply member load of 4 kN/m on the rafter
• Apply member load of 7.5 kN/m on the secondary beams
• Form load combination 1.5DL+1.5LL

Procedure:

• Open the STAAD file.
• Go to Loading Tab, and click on Loading Tab and Add loading case.

• Select the Load Type as Dead and give the name as Dead Load and assign the Self Weight for different Strucutral Element under this load case.

• Selfweight has been assigned to all structural element.
• Now, similarly under the Dead Load Case add 3kN/m Member load on Rafter.

• Now, add 6 kN/m member load on Secondary beam.

• Now, assign the Nodal load of 20 kN on point of intersection of Rafter and inclined chord.

• Dead Load has been assigned.

• Now, similarly we create case for Live Load and apply the load as shown in below figure.

• Final Loading Diagram after applying Dead Load and Live both will be as shown in figure.

• Now, we will define a load combination of 1.5DL +1.5LL as shown in figure.

• Click on Add and the load combination has been added in Load Case.

Result: All the given Dead Load and Live Load cases has been created succesfully.

Solution.2)

Aim: To run the analysis and find following results on the member mentioned

• Run the analysis
• Find the Maximum Moment in the Secondary beam for 1.5DL+1.5LL case
• Find the Maximum Axial force on the inclined bracing and identify the member having the maximum force for 1.5DL+1.5LL case
• Identify Bottom chord of Truss having Maximum shear Force & Maximum moment for 1.5DL+1.5LL case and present the values.

Procedure:

• Since, the loading has been done already, we will run the analysis.
• Go to Analysis Tab, click on last load case and click on Define Commands.

• Now, click on All option and then click on Add.

• Now, click on Run Analysis on Tab.

• Analysis will be going on and window will pop up after the analysis.

• Click on View Output file to view the results.

• Final Result of the analysis will be pop-up in different window as shown below

• Now, we will find the Maximum moment in the secondary beam for 1.5DL + 1.5LL case.
• Go to Post Processing Option on Left Side. Go to View and select on Secondary beam to view.

• After only selecting only Secondary Beams, Go to Result Tab, and select `M_z` to view the Bending Moment Diagram.

• Go to annotate option to view the Maximum Bending Moment.

• Now, we can get the maximum values of Bendig Moment as 54.268 kN-m.

• Similarly, we will now find the maximum axial force on the inclined bracing for 1.5DL+1.5LL Case.

• Maximum Axial force we got as 153.934kN on Beam Number 1160 and 1161.
• Now, we can get the Maximum Shear Force and Maximum Bending Moment for the bottom chord of the Roof Truss as 2.40 kN and 3.925 kN-m.

Result: These are following results obtained on analysis:

• Maximum Moment in the Secondary beam for 1.5DL+1.5LL case = 54.268 kN-m.
• Maximum Axial force on the inclined bracing and identify the member having the maximum force for 1.5DL+1.5LL case = 153.934 kN
• Maximum ShearForce and Maximum Bending Moment for the bottom chord of the Roof Truss as 2.40 kN & 3.925 kN-m.

Solution.3)

Aim: To identify the Warnings and fix the same and run the analysis for the given STAAD File.

Procedure: After running the analysis 8 warning messages were displayed as shown in below figure.

Reason for Error: A joint exists where the only structural components connected at that node are truss members, there is no rotational stiffness at that node along any of the global d.o.f.

Remedy: Go to Speciification menu to create Master Node.

• Run the analysis again to see if there is any warning message left.
• We can see that warning message has been resolved.

Result: Analysis has been done and 8 warning messages showing were resolved successfully and analysis report with 0 warning message has been obtained.

Solution.4)

Aim: To apply Design parameter for structure modelled for code IS 800:2007.

• Effective Length Lx, Ly, Lz for beams, Truss elements
• Effective length factors Ky, Kz for Columns
• Apply other design parameters for respective members

Procedure:

• Go to analysis and design tab, select all the structural members and assign steel as the basic material.
• On the right hand side, select the IS 800 code as shown in below figure.

• Now, define the parameter for the like `L_y,L_z` for beams and trusses and `K_y , K_z` for columns.

• Now, run the analysis again to see that there is no error.

• Other parameters have also been applied.

Result: Design parameter has been successfully applied to the modelled structure iin STAAD.PRO.