Structural Steel Checks - AISC - CAESAR II - Help

CAESAR II Users Guide (2019 Service Pack 1)

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English
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CAESAR II
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CAESAR II Version
11.0 (2019)

Main window ribbon: Analysis > Steel > AISC

Performs an AISC code check on structural steel elements. Compliance is evaluated according to the AISC (American Institute of Steel Construction) code. This code check uses the forces and moments at the ends of the structural members, computes stresses, and allowables, and determines a unity check value. If the unity check value is less than 1.0, the member is acceptable for the given loading conditions. CAESAR II performs the AISC unity check according to either the 1977 or the 1989 edition of the AISC code.

Member properties are obtained from the AISC database and used to compute the actual and allowable stress values for the axial and bending terms comprising the unity check equations. The database must be either AISC77.BIN or AISC89.BIN and is set using Tools > Configuration/Setup. For more information, see Configuration Editor.

There are a few differences between the 1977 and 1989 AISC Code Revisions that affect unity check computation. The most noticeable difference is that the 1989 code provides a method for computing the unity check on single angles. This procedure, which was not addressed in the 1977 code, can be found in a special code section following the commentary. The steps necessary to compute the unity check for single angles can be followed by reviewing the message file (generated upon request).

The other differences between these two code revisions deal with members in compression. Several constants for Qs have been altered, and a new factor kc” has been added. “kc” is a compression element restraint coefficient defined in the 1989 edition of the code.

Because of these code differences, CAESAR II stores the name of the active database in the input file for the AISC module when the data file is first created. Attempting to switch databases or compute unity checks on angles using the 1977 code generates error messages and processing terminates. You are urged to consult the applicable AISC Manuals when using this command.

To begin the unity check calculations, specify a new job name in the New Job Name Specification dialog box or click Browse to navigate to an existing job file.

All CAESAR II analyses require a job name for identification purposes. After you create or open a job, you can enter input data and then define, analyze, and review your data.

The software displays the AISC window, which consists of two input screens: Global Input and Local Member Data Tab.

Output Reports

You can direct the output reports to the screen or to a printer. The output report begins with a one page summary describing the current global data and units, as shown below.

The remaining pages in the output report show the data for the individual members. The last column of the report contains the most important data (namely the unity check value) and the governing AISC equation. A sample member output reports are shown below. The report is applicable to jobs where side sway is allowed.