Steel Columns Design

The program performs the design of a steel member subjected to axial load and bending moments about its two principal axes. The program is based on the AISC ASD/LRFD methodology and checks the axial, bending, and combined stresses according to the AISC 360 Specifications (13th Ed.).

One of this program's feature is its ability to analyze a section without the necessity of entering its properties, since the program works from a biult-in database of steel sections.

Input Data

The input data required by the program includes steel yield strength, axial load, and member length. In addition, the effective length K-factors in both X and Y directions are required.

For bending about the strong axis (X), the unbraced length and the moments applied at the ends are required, as well as any moment larger than these. In addition, it is necessary to specify if sidesway exists and if any loading is applied transversely. As a guide, the program computes the Cm and Cb factors; however, the user is allowed to choose these values or any other if desired.

For bending about the weak axis (Y), the input data is the same as above, except that the unbraced length and the Cb factor are not required.

The sign convention adopted for the applied loads and the denomination of the axes is shown in figure at right.

Example

As an example, consider the 12-ft beam-column W14x61 of A36 steel subjected to the loads shown in figure to the left.

Assume that lateral buckling is prevented. The column is braced at its mid-length against buckling in the weak direction. Check the adequacy of the design.

Output

To specify the section to be analyzed, choose the Select option from the Design menu or double click the section designation fieldin the template.

The program automatically computes the maximum stresses for the column and checks the adequacy of the section selected. The figure to the right shows the template with the example data related to this program.

In this example, the axial, bending and combined stresses are below the allowable values. Therefore the design is correct.