This tab allows the user to apply previously created wind load type on the structures through the means of a load case. If the model already contains previously defined wind load cases, a dialogue box resembling the one shown will appear.
Select type:
Choose a previously defined wind load type from the drop down list.
Direction:
Specify the global direction in which the wind load is to be generated by clicking the X, Z, -X or –Z radio button. When wind is generated in X direction, the wind load is applied on the near side and when –X is chosen the load is applied on the far side. Generation in Z or –Z also works the same way.
Factor:
Specify the factor to multiply the calculated wind loads.
Open structure:
By default, the load generation is based on the assumption that the region between members is covered by panels. To generate loads on open structures like highway signs or transmission towers, switch on this box. The members are selected and X is used and the factor is positive, then the exposed surface facing in the –X direction will be loaded in the positive X direction. If X and a negative factor, then the exposed surface facing in the X direction will be loaded in the negative x direction. If –X is entered and a positive factor, then the exposed surfaces facing in the +X direction will be loaded the positive X direction.
Chapter- 5:
1. Analysis
2. Concrete Design 3. Time History Analysis
Analysis
STAAD.Pro V8i offers STAAD engine for general purposes structural analysis and design.
The modelling mode of STAAD environment is used to prepare structural input data.
After the analysis is performed, used the menu option File→ View→ Output File→ STAAD Output to view the output files.
The STAAD Analysis engine perform analysis and design simultaneously. However, to carry out the design, the design parameters too must be specified along with the geometry, properties, etc. Before you perform the analysis. Also, note that you can
change the design code to be followed for design and the code check before performing the analysis/design.
Perform analysis:
To do the analysis must be need to add the command from Commands→ Analysis→
Perform analysis…
This allowed the user to specify the instructions for the type of analysis to be performed using STAAD engine. In addition, this command may be used to print various analysis-related data such as load information, statics check information, mode shapes etc.
The analysis menu offers several sub menu options. When you select one of the analysis commands, you may specify the analysis-related data to be printed in the STAAD output (.ANL) file by selecting the print option radio buttons, explained below:
Load data: print all the load data.
Statics check: provides summation of the applied load and support reaction as well as summation of moment of load and reactions taken around the origin.
Statics load: print everything that statics check does and summation of all internal and external forces at each joint.
Mode shapes: print mode shapes values at the joints or are calculated mode shapes.
Both: this option is equivalent to the load data plus statics check option.
All: this option is equivalent to load data plus statics data.
Run Analysis:
The Analysis is performed under the commands under the analyse menu in the Modelling Mode. Select the Run Analysis option to perform Analysis/Design.
The Analysis Status dialog box appears:
This dialog box displays the status of the analysis process. If an error occurs during the analysis, the above dialog box displays the error message.
View Output File: it will invoke the STAAD viewer with the analysis results presented in a textual format.
Go to Post Processing Mode: it will take you to the STAAD.Pro Post processor where you can graphically.
Stay in Modeling Mode: it will keep you in Modeling environment.
During the analysis, an output file is generated. This file may contain selected input data items, results and error messages. To include a report of the input data items in the output file, use the menu options under Commands | Pre Analysis Print. The generated output file may be viewed using the menu option File | View | Output File | STAAD Output.
Any errors that occur during the analysis process may be viewed using the menu option File→ View→ Output File.
Concrete Design
STAAD has the capabilities of performing concrete design on limit state method of IS 456 (2000).
Beam Design:
Beams are designed for flexure, shear and torsion. If required the effect the axial force may be considered. For all these forces, all active beam loadings are pre-scanned to identify the critical load cases at different section of the beams.
Column Design:
Columns are designed for axial forces and biaxial moments at the ends. All active load cases are tested to calculate reinforcement. The loading which yield maximum
reinforcement is called the critical load. Column design is done for square, rectangular and circular sections. By default, square and rectangular column and designed with reinforcement distributed on each side equally for the sections under uni-axial moment.
Design Parameters:
The program contains several parameters which are needed to perform design as per IS 456 (2000). Default parameter values have been selected that they are frequently used numbers for conventional design parameters. These values may be changes to suit the particular design performed.
Performing Concrete Design:
1. Click Commands→ Design→ Concrete Design.
2. Now the user can specify the design parameters for the structure.
3. Concrete Design dialog box appears.
4. Click the Select Parameters button. Now you can select the desired parameters for the concrete design.
5. Click Ok. Then Click Define Parameters button, now you can define the parameter
Important Parameters To Be defined Are Given Below:
Parameter Name Default Value Description
FC 25000 KN/mm2 Concrete yield strength.
FYMAIN 415000 KN/mm2 Yield stress for main reinforcing steel.
FYSEC 415000 KN/mm2 Yield stress for secondary reinforcing steel.
MAXMAIN 60 mm Maximum main reinforcement bar size.
MAXSEC 12 mm Maximum secondary reinforcement bar size.
MINMAIN 10mm Minimum main reinforcement bar size.
MINSEC 8 mm Minimum secondary reinforcement bar size.
6. Now Click Commands button, Design Commands dialog box appears.
7. Click Add button to add the parameters, then assign the commands to the respective members.
8. Assign the DESIGN BEAM to the members parallel to X and Z direction.
Click Select→ Beam Parallel To X.
Click Select→ Beam Parallel To Z.
9. Assign the DESIGN COLUMN to the members parallel to Y direction.
Click Select→ Beam Parallel To Y.
10. Then Run Analysis, the result provide the suitable concrete design for the structure.
NOTE: After the analysis, double – click the member of the structure, it show the concrete design, if the concrete design of the element is missing, then it is said to unsafe.