"Test verification of the effect of stress gradient on webs of Cee and Zee sections "


The scope of work includes the following

  • Reviewing results of recent research projects (see Appendix) that presented new formulations for the analysis of Cee and Zee sections in flexure resulting in stress gradients in the webs.
  • Designing an appropriate test program to meet the objectives.
  • Conducting flexural tests on Cees and Zees
  • Comparing the test results with strength predictions using the proposed formulations and procedures.
  • Preparing a comprehensive report with comparisons of the test results with analytical predictions.

Proposed contractors will designate a Project Director responsible for all phases of the work. The Contractor may use sub-contractors for portions of the work, but the contractor retains responsibility for the final product. The Subcontractor must be approved by AISI.


The objective is to develop a database of flexural tests where the web is subjected to a stress gradient in order to confirm the proposed methodology for the analysis of webs with stress gradients. The test matrix should be designed to have the widest practical variation in parameter related to the member web. These parameters include H/T, D/W, and location of the neutral axis. The test should be designed to minimize the effect of other parameters such as interaction with a roof or wall system and other external effects. The proposal should indicate the approach to be used in designing the test program and a preliminary test matrix indicating the number of specimens that will be tested.


If the proposal is accepted, a contract will be awarded within 30 days. Progress reports must be submitted every three months. A draft of the final report must be submitted by the Contractor within twelve months after receiving the contract for review by the Committee on Specifications. Comments will be furnished within a reasonable time to allow the Contractor to promptly make final revisions.


The contractor shall submit one camera ready copy to facilitate the publishing of findings as an AISI Research Report. In addition, the contractor shall provide text and graphics for a ballot in Specification-type language. The contractor shall also provide an electronic copy of the report on computer disk. The preferred format is DOS compatible Microsoft Word or WordPerfect 5.1. An electronic document in PDF format is also encouraged.

All the test data should be available to other researchers in an electronic format. The preferred format is DOS compatible Microsoft Excel or Quatro-Pro.


Cees and Zees are used extensively in all types of building construction; they are probably the most common shape produced in cold-formed members. The effect of stress gradient on flexural webs is essential to the development of reliable, efficient designs.


Proposal must be received no later than June 30, 2000, at the following address:

Helen Chen, Senior Engineer
Cold-Formed Steel Construction
American Iron and Steel Institute
1101 17th Street, NW, Suite 1300
Washington, DC 20036-4700

7. Qualifications

All proposals must be accompanied by a brief resume of personnel who will work on the project. The resume should identify those qualities and experience which relate to cold-formed steel design and structural testing.


  1. Schafer, B.W., and Peköz, T., (1998). "Laterally Braced Cold-Formed Steel Flexural Members with Edge Stiffened Flanges." Proceedings of the Fourteenth International Specialty Conference on Cold-Formed Steel Structures, St. Louis, MO.
  2. Schafer, B.W., and Peköz, T., Cold-Formed Steel Behavior and Design: Analytical and Numerical Modeling of Elements and Members with Longitudinal Stiffeners-Final Report.
  3. Schafer, B.W., and Peköz, T., Final Report - Intermediate Stiffened Elements and Webs-Part II, Behavior and Design of Cold-Formed Steel Elements Under a Stress Gradient with a Longitudinal Intermediate Stiffeners
  4. Schafer, B.W., Impact of Proposed Changes in AISI Specification for Effective Width of Webs on Industry Standard Sections
  5. Schafer, B.W., Pekoz, T., Final Report and Addendum of Direct Strength Prediction of Cold-Formed Steel Members Using Numberical Elastic Buckling Solutions
  6. Schafer, B.W., AISI Specification Mock-up, Direct Strength Approach
  7. Hancock, G.J., Y.B. Kwon and E.S. Bernard (1994), "Strength Design Curves for Thin-Walled Sections Undergoing Distortional Buckling," Journal of Constructional Steel Research, Vol. 31, 1994.