Ductility of G550 Sheet Steels in Tension

Cold formed structural members are fabricated from sheet steels which must meet various material requirements prescribed in applicable national design standards. These requirements ensure that (1) Stress concentrations can be redistributed; and (2) members and connections can undergo a minimum amount of displacement without a loss in structural performance. The 1996 Australian/New Zealand (AS/NZS 4600) and 1996 North American (CSA-S136 and AISI), Cold Formed Steel Design Standards allow for the use of thin (t< 0.9 mm), high strength (fy= 550 MPa) sheet steels if the yield stress and ultimate strength are reduced to 75% of their minimum specified values. This paper provides a summary of results detailing the ductility and net cross-section tensile resistance of G550 sheet steels (to the 1993 Australian Standard AS 1397), tested as solid and perforated coupons. Material properties of the test specimens are compared with the Dhalla and Winter requirements for ductility and ultimate strength to yield stress ratio. Limit states tensile design equations are calibrated according to procedures defined by the 1996 American Iron and Steel Institute (AISI) Commentary.