Week 9 Challenge

1. Design of dual slope (pitched) roof frame

Aim & Introduction- To Design a 3 hinged pitched roof frame of a steel building, Analyse the frame structure and draw bending moment, shear force and axial force diagrams of the frame.

Given data- The slope of the roof is 1 in 10 and the roof is accessible for maintenance purpose (assume 75 kg/m²) only.

Assume bay spacing as 5 m and frame width is 20 m. (Design code as per AISC:ASD. )

Weight of roofing sheet = 5kg/m²

Weight of purlins + tertiary members = 25 kg/m²

^{Procedure in detail -}

^{Usiung Node command plot (0,0 0) & (10,0,0)}

^{Using Add beam command join two Nodes}

^{Using Transition Repeat draw a beam at Y =5m ( Assuming height of column)}

Now delete the bottom beam after selecting and using delete command

^{Delete one column on right side}

^{Move Node No # 4 vertically by 1 m for maintaining slope of 1:10}

^{Using Mirror command complete the frame}

^{Add Hinge support at two columns using Support command}

^{Assigning ISMB 400 to both thed Columns ( Property Assignment)}

^{Assigning ISMB 350 to the Rafter ( Property Assignment)}

^{Applying Dead Load & Live load on the Rafter as per calculation given below -}

^{a) Self weigh}

^{b) Wt of Roffing sheet @ 5 Kg/SqM + Wt of Purlin & Tertiary members @ 25 Kg/SqM}

^{Thus Total Dead Load on rafter will be (25+5)x Bay width wich is 5m =150 Kg/SqM= 1.5 KN/m ( As given frame is main frame)}

^{Live Load = 75 Kg/Sqmx 5 = 0.375 KN/m}

^{Dead load :Self Weight+ Wt of Roffing sheet +Wt of Purlin & Tertiary members}

^{Live Load-}

Load combination: 1.5 DL+1.5 LL

Analysing the model/structure using Run Analysis command

Model is analyse with 0 Errorr, 0 Warning & 0 Note

Bending Moment diagram is given below

Shear Force diagram is as given below-

Axial Force diagram is as follows-

Result:

It is concluded that the given model is analyse successfully with 0 Error 7 0 warning without any Note and BMD, SFD & Axial Force diagrams are drawn as above. The Staad Pr0 file is also attached for Run analysis

Q2. Draw Bending Moment diagram for following Frame using STAAD.Pro

Figure 1)

Aim & Introduction- To draw Bending Moment Diagram of the given model with following given data-

Span = 20 m

Height of the column = 10 m

Slope = 5.71 Degree

Support Conditions = Fixed support at two exterior columns & Pinned support at middle column

Loading = 20 KN/m UDL on Rafter & 10 KN Nodal load along X direction at node A & C

Procedure- First of all model is prepared with given data as shown below-

Run analysis command has been performed successfully without any Error ,Warning & Note as shown below in the print screen

Bending Moment Diagram of the model for given loading is as shown below in the print screen-

Staad pro model file is attached herewith-

Result : It is concluded that Bending Moment Diagram is as drawn above

Q2 (Fig-2)

Aim & Introduction- Bending Moment Diagram of given frame is required to be drawn using Staad.Pro software ,

Given data for frame: Mono pitched roof frame with span= 10 m

Column height on one side =20 m

Slope angle= 20 Degree

Columnt height of other column = 20 m - 10x tan(20degree) = 16.603

Support Conditions: Both columns are Hinged supported

Loading : UDL of 30 KN/m on pittched roof & 10 KN of Nodal load at the node of shorter column and beam

Procedure : Frame with given data is created using, Loading is assigned as per given detaials and member properties are also assigned .

Run analysis command has been performed successfully without any Error ,Warning & Note as shown below in the print screen-

BMD is as given below which has been captured as print screen in Post processing-

Result: Bending Moment Diagram is shown above for most critical load combination ( case-4). Thus it is concluded that Bending Moment is max for load combination -4. Staad.Pro file is also attached for executing various coomand.

Q2 (Fig-3)

Aim & Introduction- Bending Moment Diagram of given frame is required to be drawn using Staad.Pro software ,

Given data for frame: Frame with span= 8 m

Column height on one side =10 m

Support Conditions: Both columns are Hinged supported and also hinged at the center center of beam there is hinge

Loading : Nodal load of 10 KN/m at hinged support of roof beam & UDL of 10 KN/m on the column on left side alonf X axixs.

Procedure : Frame with given data is created using, Loading is assigned as per given detaials and member properties are also assigned .

Run analysis command has been performed successfully without any Error ,Warning & Note as shown below in the print screen-

BMD is as given below which has been captured as print screen in Post processing-

Result: Bending Moment Diagram is shown above for most critical load combination ( case-4). Thus it is concluded that Bending Moment is max for load combination -4. Staad.Pro file is also attached for executing various coomand.

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

1) Aim & Introduction- Lateral deflection at point A and vertical deflection at mid section of Beam between B & C from figure-1 in previous chaalenge i.e. challenge-2 ( Fig-1) are required to be determined.

Procedure-

With the model of challenge-2 ( Fig-1) using Run Analysisi command in the Analysis and Design option then in the Post Processing option displacement command for load combination case-3 give the maximum deflection as shown below-

Deflection at A is 0.727 mm as shown in the print screen given below-

Max deflection at mid point of beam between B & C is 22.626 mm as shown below-

Staat.Pro file is already attached against Challenge-2 through which max deflection ( Load case-3) can be viewed using deflection command in the Post Processing after performing Run Analysis command in Analysis and Design.

Result: it is concluded that the deflection at point A = 0.727 mm & at mid point of beam between B & C is 22.626 mm

Q-3(2) Aim & Introduction- Lateral deflection at point A and vertical deflection at mid section of Beam between A & B from figure-1 in previous chaalenge i.e. challenge-2 ( Fig-2) are required to be determined

Procedure-

With the model of challenge-2 ( Fig-2) using Run Analysisi command in the Analysis and Design option then in the Post Processing option displacement command for load combination case-3 give the maximum deflection as shown below-

Deflection at A is 931.174 mm as shown in the print screen given below-

Max deflection at mid point of beam between A & B is 629.147 mm as shown below-

Result: it is concluded that the deflection at point A = 931.174 mm & at mid point of beam between B & C is 629.147 mm

Q-3(3) Aim & Introduction- Lateral deflection at point A a & B from figure-3 in previous chaalenge i.e. challenge-2 ( Fig-3) are required to be determined

Procedure-

With the model of challenge-2 ( Fig-3) using Run Analysisi command in the Analysis and Design option then in the Post Processing option displacement command for load combination case-3 give the maximum deflection as shown below-

Deflection at A along X Axis = 0.052 , Along Y Axis = 0.098 mm and Resultant displacement is 0.11 mm as shown in the print screen given below-

Deflection at B along X Axis = 0.00 , Along Y Axis = 0.00 mm and Resultant displacement is 0.00 mm as shown in the print screen given below-

Result: it is concluded that the Ressultant deflection at point A = 0.11 mm & at B is 0.00 mm