The criteria used in the analysis and design of beams with web openings are set in the Criteria menu in the RAM Steel Beam Design module.

The design code is selected using the Criteria > Steel Design Codes command. Web openings can be used in conjunction with the AISC 360 ASD, AISC 360 LRFD, ASD 9th and LRFD 3rd, BS 5950, and the Eurocode steel design codes. Web openings are ignored if any other design code is selected.

• When AISC ASD or LRFD is selected, the design of the web openings is based on:

  "Steel Design Guide #2: Steel and Composite Beams with Web Openings", David Darwin, 1990, published by AISC.

• When BS 5950 is selected, the design of the web openings is based on:

  "Design for openings in the webs of composite beams," SCI Publication 068, R.M. Lawson, 1987, published by Steel Construction Institute.

• When Eurocode is selected, the design of the web openings is based on:

  "Design of composite beams with large web openings, In accordance with Eurocode and the UK National Annexes" SCI Publication 355, R.M. Lawson, S.J. Hicks, 2011, published by Steel Construction Institute.

These publications will be subsequently referred to herein as Design Guide #2, SCI Publication 068, and SCE Publication 355, respectively.

Criteria related to the stiffeners can be specified in the Criteria > Web Openings command. During optimization or analysis of the beam, the effects of the web openings on the beam are considered. If necessary, the program will design stiffeners above and below the openings.

The yield strength of the stiffener plates is specified in that dialog box.

The minimums and increments of the dimensions of the stiffener plates can be specified. The program will select stiffeners, when necessary, that are sized as required but that are at least the minimum size specified. The sizes are rounded up to the multiple of the increment specified.

Stiffeners placed on only one side of the web are often acceptable and more economical. They are not always desirable, however, because they cause the beam to be asymmetrical (which can be a problem in cases of long unbraced lengths). The program will investigate the design of web openings with stiffeners on one side of the web if that option is selected, otherwise it will not.

It may be more economical to use deeper, heavier beams rather than adding any stiffeners. If neither option to allow stiffeners is selected, the program will optimize to the beam size that does not require stiffeners at the openings. On the other hand, if depth of beams is a concern, lighter, shallower beams may be obtained if stiffeners are allowed.