Program Description:

"STIFFNER" is a spreadsheet program written in MS-Excel for the purpose of analysis of steel beams subject

to concentrated loads. Specifically, web yielding, web crippling, and web buckling criteria are checked to

determine if web stiffeners are required to resist the concentrated load. If stiffeners are required, the stiffener

size and weld requirements are determined.

This program is a workbook consisting of three (3) worksheets, described as follows:

Program Assumptions and Limitations:

1. This program follows the procedures and guidelines of the AISC 9th Edition Allowable Stress (ASD) Manual

for wide flange beams subjected to concentrated compressive loads per Chapter K, pages 5-80 to 5-83.

2. This program uses the database of member dimensions and section properties from the "AISC Shapes

Database", Version 3.0 (2001) as well as the AISC 9th Edition (ASD) Manual (1989).

3. For the purpose of determining the total composite section to be considered for resisting the compressive

load, the program assumes a spacing of 3" center-to-center between the stiffener pairs. Thus the total

effective strips of web to be included in the composite section along with the stiffeners are as follows:

For interior condition (P or R > d/2):

1-pair: 25*tw

2-pairs: 25*tw+3"

3-pairs: 25*tw+6"

For end condition (P or R <= d/2):

1-pair: 12*tw

2-pairs: 12*tw+3"

3-pairs: 12*tw+6"

4. This program contains numerous “comment boxes” which contain a wide variety of information including

explanations of input or output items, equations used, data tables, etc. (Note: presence of a “comment box”

is denoted by a “red triangle” in the upper right-hand corner of a cell. Merely move the mouse pointer to the

desired cell to view the contents of that particular "comment box".)