Session Start Date

10-17-1996

Abstract

This paper reports the findings of an investigation of the flat width ratio limit for simple edge-stiffeners of channels in bending. Willis & Wallace concluded that the lip flat width ratio limit, d/t, should have a value of 14 based on a comparison of the 1980 and 1986 editions of the American Iron and Steel Institute (AISI) Cold Formed Steel Specification. This conclusion was made using the results of only three channel beam tests with various lip sizes, Case III flanges and locally unstable webs. The CAN/CSA-S136 Technical Committee adopted the recommendations of Willis & Wallace and included the lip flat width ratio limit in the 1989 and 1994 S136 Standards. A test program was initiated at the University of Waterloo to investigate the findings of Willis & Wallace. The investigation consisted of the testing and analysis of 44 C-section beams with Case I, II and III flanges, locally stable and unstable webs, and systematically varied lip depths. The d/t and dáµ¢/w ratios of these C-sections were compared with the applied test moments and flange "Cases". The objectives of this study were to determine when the use of the existing d/t limit is required, if its current value is accurate, and whether it should remain in the next edition of the S136 Standard. Analysis of the Waterloo, as well as, the Willis & Wallace test data revealed that a d/t or dáµ¢/w limit is not required in the S136 Standard.

Department(s)

Civil, Architectural and Environmental Engineering

Research Center/Lab(s)

Wei-Wen Yu Center for Cold-Formed Steel Structures

Meeting Name

13th International Specialty Conference on Cold-Formed Steel Structures

Publisher

University of Missouri--Rolla

Publication Date

10-17-1996

Document Version

Final Version

Rights

© 1996 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

Share

 
COinS
 
Oct 17th, 12:00 AM

Cold Formed Steel Flat Width Ratio Limits, D/t and Dáµ¢/w

This paper reports the findings of an investigation of the flat width ratio limit for simple edge-stiffeners of channels in bending. Willis & Wallace concluded that the lip flat width ratio limit, d/t, should have a value of 14 based on a comparison of the 1980 and 1986 editions of the American Iron and Steel Institute (AISI) Cold Formed Steel Specification. This conclusion was made using the results of only three channel beam tests with various lip sizes, Case III flanges and locally unstable webs. The CAN/CSA-S136 Technical Committee adopted the recommendations of Willis & Wallace and included the lip flat width ratio limit in the 1989 and 1994 S136 Standards. A test program was initiated at the University of Waterloo to investigate the findings of Willis & Wallace. The investigation consisted of the testing and analysis of 44 C-section beams with Case I, II and III flanges, locally stable and unstable webs, and systematically varied lip depths. The d/t and dáµ¢/w ratios of these C-sections were compared with the applied test moments and flange "Cases". The objectives of this study were to determine when the use of the existing d/t limit is required, if its current value is accurate, and whether it should remain in the next edition of the S136 Standard. Analysis of the Waterloo, as well as, the Willis & Wallace test data revealed that a d/t or dáµ¢/w limit is not required in the S136 Standard.