Week 9 Challenge

Analysis & design of Typical Steel Frame structure using STAAD. Pro (100 marks – 45 mins)

1. Design of dual slope (pitched) roof frame

Design a 3 hinged pitched roof frame of a steel building. Assume no wind load acting on the walls and roof. Analyse the frame structure and draw bending moment, shear force and axial force diagrams of the frame. The slope of the roof is 1 in 10 and the roof is accessible for maintenance purpose (assume 75 kg/m²) only. Dead load on the roof are given below. Assume bay spacing as 5 m and frame width is 20 m. (Design code as per AISC:ASD. No seismic load consideration required)

Weight of roofing sheet = 5kg/m²

Weight of purlins + tertiary members = 25 kg/m²

Given data:-

Roof Slope 1:10

Bay Spacing = 5 m

Live Load = 75 kg/m² = 0.735 kN/m² = 0.735 x 5 = 3.675 kN/m

Dead Load = 5 kg/m² + 25 kg/m² = 30 kg/m² = 0.294 kN/m² = 0.294 x 5 = 1.47 kN/m

Aim:-

To Design a 3 hinged pitched roof frame of a steel building and draw bending moment, shear force and axial force diagrams of the frame.

Procedure:-

Step 1:-

• Open the STAAD Pro Software and create a new model as shown below.

• Using Nodes and Beams option draw the Frame as shown below.

Step 2:-

• Define Section properties in the Properties Tab.

• Then assign Sections to the members.

• Now create and assign the Pinned support

Step 3:-

• Add Dead Load, Live Load and Load Combination to the members.

Step 4:-

• Now go to Analysis Tab and Define Perform Analysis.

• Output shows 0 Error and 1 Warning.

Result:-

• ^{The given frame was analysed and the bending moment, shear force and axial force diagram created.}

Bending Moment diagram

Shear Force diagram

Axial Force diagram

2. Draw Bending Moment diagram for following Frame using STAAD.Pro

Figure 1)

Aim:-

To draw Bending Moment diagram for the frame given using STAAD Pro.

Procedure:-

Step 1:-

• Draw the frame using Nodes and Beams option.

Step 2:-

• Define and Assign the Section properties to the member.

Step 3:-

• Then create and assign the support to the frames.

Step 4:-

• Add Load cases given and assign to the frame members.

Step 5:-

• Go to Analysis Tab, define Perform Analysis.
• Then Click Run Analysis.

• Output shows 0 Errors and 0 Warnings.

Result:-

• Bending moment diagram was drawn for given frame successfully.

Figure 2)

Aim:-

To draw Bending Moment diagram for the frame given using STAAD Pro.

Procedure:-

Step 1:-

• Draw the frame using Nodes and Beams option.

Step 2:-

• Define and Assign the Section properties to the member.

Step 3:-

• Then create and assign the support to the frames.

Step 4:-

• Add Load cases given and assign to the frame members.

Step 5:-

• Go to Analysis Tab, define Perform Analysis.
• Then Click Run Analysis.

• Output shows 0 Errors and 1 Warnings.

Result:-

• Bending moment diagram was drawn for given frame successfully.

Figure 3)

Aim:-

To draw Bending Moment diagram for the frame given using STAAD Pro.

Procedure:-

Step 1:-

• Draw the frame using Nodes and Beams option.
• Define and Assign the Section properties to the member.
• Then create and assign the support to the frames.

Step 2:-

• Add Load cases given and assign to the frame members.

Step 3:-

• Go to Analysis Tab, define Perform Analysis.
• Then Click Run Analysis.

• Output shows 0 Errors and 0 Warnings.

Result:-

• Bending moment diagram was drawn for given frame successfully.

3. Deflection of a frame, present result from STAAD.Pro

1. Determine the lateral deflection at point A & Vertical deflection at mid section of beam between B & C from Figure 1 in previous challenge.
2. Determine the lateral deflection at point A & Vertical deflection at mid section of beam between A & B from Figure 2 in previous challenge.
3. Determine the lateral deflection at point A & point B from Figure 3 in previous challenge.

Answer:-

Figure 1:

The lateral deflection at point A = 0.090 mm

Vertical deflection at mid section of beam between B & C = 27.846 mm

Figure 2:

The lateral deflection at point A = 1003 mm

Vertical deflection at mid section of beam between A & B = 1005 mm

Figure 3:

The lateral deflection at point A = 0.051 mm

The lateral deflection at point B = 0.000 mm