Week 8 Challenge

Loading, Analysis and Design Procedure in STAAD Pro

1. Applying Load Exercise

For the structure modelled in previous exercise. Apply following loads

• 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:

• Go to loading option in the load case details.
• Add load such as dead load and live load
• In member Load put loads as per given data.
• Choose Y direction to aapply load.
• Negative sign act as a downward direction.
• Assign load to selected member as per given data.
• For nodal load go to add at FY point.
• Assugn load to selected nodal points.
• For load combination go to load combination option.
• Select dead load,live load and apply as per given data.
• Here we can take as servicibility criteria so add one additional load combination.

1DL+1LL

Afeter that add load combination.

2. Find Maximum Force and Minimum Force for member and present the STAAD result.

Continue previous challenge, 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:

• Maximum moment for secondary beam 1.5DL+ 1.5LL- 53.343 KNm
• Maximum Axial force for inclined bracing- 456.949 KN
• Member on which it acts maximum force for 1.5 DL+1.5 LL case- Beam member no 13.
• Maximum shear force for bottom chord-260.262 KN
• Maximum moment for bottom chord-420.855 KN
• Member on which maximum shear force and maximum moment for 1.5DL+1.5LL- Beam member no 1.

3. View and Rectify the Warning, instabilities in the structure

For the attached STAAD file identify the Warnings and fix the same and run the analysis.

Procedure:

• Go to given attachment.
• Open the model of structure.
• After go run analysis option
• Choose perform analysis and run the analysis.
• See the warning in view option.
• See the instability in the result layout option.
• Choose that and fix it.
• After all warnings fixed run the analysis and see the results.
• For warning jin the joints 47 and 48 fix it.
• After the run analysis we found that there is instability occured.
• Go to results view instability for the points.

4. Design Parameter exercise

In continuation to challenge 1, Apply Design parameter for structure modelled for code IS800:2007.

• 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 analysiis and design select stteel as material.
• Select IS 800:2007 code
• Define design parameters.
• Apply it on beam and truss element.
• Here we take Lx- not applicable
• Ly- as a default use for apply to member.
• Lz- as a default use for apply to member.
• Ky- as a factor take as 1.2 as per IS 800.
• Kz- as a factor take as 1.2 as per IS 800.
• Other parameters such beam apply to selected as 1.0
• Take utility ratio as 1.2 and apply to the structure.