Bolted Connection Tests of Thin G550 and G300 Sheet Steels

TLDR

Cold‑formed structural members made from sheet steels must satisfy national design standards that ensure stress redistribution and displacement limits, allowing thin, high‑strength steels (t < 0.9 mm, fy = 550 MPa) when yield and ultimate strengths are reduced to 75 % of the minimum values per AS/NZS 4600, CSA‑S136, and AISI. This paper investigates the shear behavior of bolted connections using thin G550 and G300 sheet steels. The authors tested connections composed of 0.42 mm G550, 0.60 mm G550, and 0.60 mm G300 sheet steels according to the 1993 Australian standard AS 1397. The study recommends that current design standards are adequate and provides calibrated limit‑state resistance equations for end pull‑out, bearing, and net‑section fracture modes.

Abstract

Cold formed structural members are fabricated from sheet steels that 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 both North American cold formed steel design standards, CSA-S136 and AISI, allow for the use of thin (t< 0.9 mm in AS/NZS 4600), 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 behavior of bolted connections tested in shear, which were composed of 0.42 mm G550, 0.60 mm G550, and 0.60 mm G300 sheet steels (to the 1993 Australian standard AS 1397). Recommendations concerning the adequacy of current design standards with respect to the design of thin sheet steel bolted connections are made, along with the calibration of applicable limit states resistance equations for the three observed modes of failure: end pull-out, bearing, and net section fracture.