ADVANCED STRUCTURES-CONICAL DOME STRUCTURE
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Data:
Spherical dome Dia : 20m
Dome Base Dia : 15m
Height of column : 7.0m
No. of Columns support : 16
Column dia. : 0.45m
Connecting beam size : 0.38 x 0.23m
Dome thickness : 0.10m
Concrete Grade : M20
Steel Grade : Fe 415
1.Geometry Creation :
New Project Select Space Units: Length =meters; Force=KN;
File Name=Conical dome Next. Select Add beam Finish.
Geometry Run structure WizardSelect Frame models from Truss modelGo to
Surface Plate ModelSpherical Surface. Type Spherical cap.
Diameter of Sphere=20m; Base Diameter=15m; Top diameter=0
Latitude: Divisions=10 Longitude: Divisions=15 Apply Transfer ModelYes
Paste Prototype Model X=0 Y=0 Z= 0Ok.
Fig. 1 Spherical Dome geometry
Isometric view. Click one end of the nodeEdit CopyPaste Y=-7mOk. Right
ClickAdd Beam. Join the column of top & Bottom nodes.
Fig. 2 Adding column to the dome
Select the column member Right clickInsert node Click
Add mid pointOk. Select the column Go to GeometryCircular
RepeatNode=161 Y Total angle=360 No. of steps=16 Tick Link steps
Open base Ok.
Fig. 3 circular repeat for creating column
Select the columns & Beams structure Go to LabelsStructure : inner plates:
Blue: Outer Plates: RedOk.
Fig. 4 Geometry of model created
Fig. 5 Structure after selecting labels and Fill with plate
2. Member Property :
Click General Property Define Circle YD=0.45m (Column) Add.
Rectangle YD=0.38 ZD=0.23 (Beam) Add Thickness node
1,2,3&4=0.1m (Dome thickness) AddClose.
Highlight YD=0.45 & Select Beam Parallel toY Assign to selected beam
Assign Yes.
Highlight YD=0.38 ZD=0.23 and select Top ring beam and middle tie beam
member Assign to selected beam Assign Yes .
Highlight thickness=0.1m & select plate cursor. Select Top Dome Structure Right
click Labels Structure None Tick Fill Plates/solids surfaceApplyOk.
3. Supports :
Click Support Create Fixed Add. Highlight support 2 and select bottom
most nodes of column by windowing using node cursor Assign to selected
nodes Assign Yes Close De select the nodes and change to beam cursor.
Fig 6 Assigning Support as fixed
4. Loading :
Click Load case Details Add.
Primary Number 1 Loading type: none Title: Load case 1 Add .
Click Load case 1 details Add.
Self weight Y Factor=-1 Add.
Plate loadsPressure on Full Plates W1=-1KN/m2 GY Add.
Highlight selfweight Select geometry cursor & select entire structure Assign to
selected beam/plates Assign Yes.
Highlight Plate Load pressure on full plates W!=-1KN/m 2 .Select Plate cursor &
choose entire structure of the domeSelect geometry cursor & select entire
structure Assign to selected beam/plates Assign Yes.
Click Load case details Add.
Click Define Combinations Load Number: 2
Name: 1.5 Load case 1 Normal Factor Default :1.5
Select Load case 1 1=1.5 AddClose.
5. Analysis Type:
Click Analysis/print No print Add Close.
Click post print Define commands Load list select Load comb AddClick
Analysis Results Add Close,
Note: Save the File before Run the Program.
6. Design :
Click Design ConcreteCurrent code :IS456 Define Parameters
Fc=20,000KN/m2 Add.
Click Design commands Design slab elements AddClose.
Highlight Fck=20000 and select plate cursor and select dome structure
Assign to selected beams/plates Assign Yes.
Go to top view & view the entire elements of the dome in plan. Select one segment
of all elements of dome for design of slab portion.
7. Analysis:
From Main Menu ` Analysis Run Analysis Done.
8.Results :
Go to post processing mode.
Select load case 2 Load comb Ok. Click Summary of results given in Table form.
Results Plate stress contour Select Load case 2 Load comb Stress Type: Max
Von Mz Apply Ok.
Fig. 7 Max. Von Mz
Fig. 8 Max. Von Mz Isometric view
Fig.9 Max. Von Mz Top view
Results Plate stress contour Select Load case 2 Load comb Stress Type: Mx
(Local) Apply Ok.
Fig. 10 Mx (Local)
Results Plate stress contour Select Load case 2 Load comb Stress Type: My
(Local) Apply Ok.
Fig. 11 My (local)
Go to Staad output Concrete design and see the reinforcement of Dome slab.
Fig. 12 Dome slab Max. & Min. Reinft.
