Introduction to STAAD

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What is STAAD

"STAAD_III for Windows / Windows NT is a comprehensive structural engineering software that addresses all aspects of structural engineering - model development analysis, design, verification, and visualization. STAAD-III for Windows / Windows NT is based on the principles of "concurrent engineering". You can build your model, verify it graphically, perform analysis and design, review the results, sort and search the data to create a report - all within the same graphics based environment."

"Following are the main options available from the Concurrent Graphics Environment:

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STAAD-III Analysis and Design

"STAAD-III performs the analysis and design of the structure. The processes of analysis and design are integrated and can be performed in the same run. STAAD-III uses a command language based input format which can be created through an editor, the powerful STAAD-PRE graphics input generator, or through CAD based input generators. Output generated by STAAD-III consists of detailed numerical results for analysis/design and sharp presentation quality printer plots as part of the run document."

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STAAD-PRE Graphical Input Generation

"The STAAD-PRE facility allows generation of structural models graphically. Powerful geometry generation algorithms facilitates generation and viewing of structural models for both 2D and 3D situations. All other specifications like section properties, material constants, supports, loads, analysis/design requirements, printing/plotting requirements, etc. are available. As the output, this option generates the STAAD-III command language based input file."

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STAAD-POST Graphical Post-Processing

"STAAD-POST is a powerful graphics facility for verification of the model and display of the results. The model verification capabilities include complete graphics verification and visualization for all items. State-of-the-art results verification capabilities include display and plotting of structure geometry, deflected/mode shapes, bending moment/shear force diagrams, stress contours, etc. A versatile "query" facility allows generation of customized reports. Powerful icon-based graphics tools provide extremely user-friendly navigation and manipulation capabilities."

 "STAAD-III can be invoked directly from the graphics environment allowing "concurrent" verification and visualization. Sharp presentation quality plots may be generated on all plotters and printers."

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STAAD Utilities

The following utilities are available within the Graphical User Interface Environment of STAAD:

"The Text Editor is available from the Main Menu as well as from the STAAD-PRE facility. It is also accessible as an independent application from the REI applications group. This can be used for creating new input file, viewing/edition an existing input file, and viewing/editing an input file created by the STAAD-PRE Graphics Input Generator."

"The View facility is available from the Main Menu as well as from the STAAD-POST facility. This facility can be utilized to view the entire output file on the screen. Both numerical data and graphics output can be viewed."

"The Print facility can be utilized to print the output file. It can be invoked both from the Main Menu and from STAAD-POST. The Plot option allows plotting of graphics. Plots generated in STAAD-POST print/plot option may be plotted directly or by using the Plot option of the Main menu."

"Data Exchange facility with CAD programs is available. The STAAD-PRE facility can read ".DXF" files to generate STAAD-III input. Both 2D and 3D ".DXF" files may be generated for graphics plots created in STAAD-POST using the Plot option."

"An interface to the Microsoft Windows Calculator is provided for quick interactive arithmetic calculations required during input generation or result verification. The Calculator is available in STAAD-PRE, STAAD-POST, and the STAAD-INTDES."

"STAAD-III for Windows / Windows NT may be interrupted by pressing Alt-Tab key any time (except while the program is performing the solution process of a problems). The user may use this facility to switch to any other WINDOWS program running concurrently. The user may also exit to DOS temporarily form the Windows environment using the MS-DOS icon in the "Main" Program Group under the Windows Program Manager. The original environment of STAAD-III for Windows / Windows NT can be resumed by switching to the STAAD-III Window using the Alt-Tab key again."

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STAAD Filenames

All STAAD input files must have an extension ".std".

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Input Generation

"The user communicates with STAAD-III through an input file. The input file is a text file consisting of a series of commands which are executed sequentially. The commands contain either instructions or data pertaining to analysis and/or design."

"The STAAD-III input file can be created through a text editor or the STAAD-PRE input generation facility. In general, any text editor may be utilized to create the input file. The input generation facility creates the input file through an interactive menu-driven graphics oriented procedure. This facility is available under STAAD-PRE..."

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Types of Structures

"A STRUCTURE can be defined as an assemblage of elements. STAAD-III is capable of analyzing and designing structures consisting of both frame and plate/shell elements. Almost any type of structure can be analyzed by STAAD-III. Most general is the SPACE structure, which is a three dimensional framed structure with loads applied in any plane. A PLANE structure is bound by a global X-Y coordinate system with loads in the same plane. A TRUSS structure consists of truss member, which can have only axial member forces and no bending in the members. A FLOOR structure is a two or three dimensional structure having no horizontal (global X or Z) applied loads or any load, which may cause any horizontal movement of the structure. The floor framing (in global X-Z plane) of a building is an ideal example of a FLOOR structure. Columns can also be modeled with the floor in a FLOOR structure as long as the structure has no horizontal loading. If there is any horizontal load, it must be analyzed as a SPACE structure. Specification of the correct structure type reduces the number of equations to be solved during the analysis. This results in a faster and more economic solution for the user."

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Unit Systems

"The user is allowed to input data and request output in almost all commonly used engineering unit systems including MKS, SI, and FPS. In the input file, the user may change units as many times as required. Mix and match between length and force units from different unit systems is also allowed. The input-unit for angles (or rotations) is degrees. However, in JOINT DISPLACEMENT output, the rotations are provided in radians. For all output, the units are clearly specified by the program."

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Structure Geometry and Coordinate Systems

"A structure is an assembly of individual components such as beams, columns, slabs, plates, etc. In STAAD-III frame elements and plate elements may be used to model the structural components. Typically, modeling of the structure geometry consists of two steps:

  1. Identification and description of joints and nodes.
  2. Modeling of members or elements through specification of connectivity (incidences) between joints."

"In general, the term MEMBER will be used to refer to frame elements and the term ELEMENT will be used to refer to plate/shell elements. Connectivity for MEMBERs may be provided through the MEMBER INCIDENCE command while connectivity for ELEMENTs may be provided through the ELEMENT INCIDENCE command."

"STAAD-III uses two types of coordinate systems to define the structure geometry and loading patterns. The GLOBAL coordinate system is an arbitrary coordinate system in space which is utilized to specify the overall geometry and loading pattern of the structure. A LOCAL coordinate system is associated with each member (or element) and is utilized in MEMBER END FORCE output or local load specification."

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Global Coordinate System

"The following coordinate systems are available for specification of the structure geometry."

  1. "Conventional Cartesian Coordinate System: This coordinate system is a rectangular coordinate system (X, Y, Z) which follows the orthogonal right hand rule. This coordinate system may be used to define the joint location and loading directions. The translational degrees of freedom are denoted by u1, u2, u3 and the rotational degrees of freedom are denoted by u4, u5, and u6."
  2. "Cylindrical Coordinate System: In this coordinate system, the X and Y coordinates of the conventional cartesian system are replaced by R (radius) and Phi (angle in degrees). The Z coordinate is identical to the Z coordinate of the cartesian system and its positive directions is determined by the right hand rule."
  3. "Reverse Cylindrical Coordinate System: This is a cylindrical type coordinate system where the R-Phi plane corresponds to the X-Z plane of the cartesian system. The right hand rule is followed to determine the positive direction of the Y-axis."

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