Ultimate Shear-Out Capacities of Structural-Steel Bolted Connections

Abstract

Based on the previous research results of the authors, this paper presents an accurate and consistent equation for determining the ultimate shear-out capacity of a structural steel bolted connection. The equation is verified against independent laboratory test results obtained by other researchers around the world. Comparisons against alternative equations found in the design specifications and literature are also included. The paper explains why certain equations appear to be accurate for particular configurations, but are grossly inaccurate for others. This paper describes the various assumptions embedded in the existing equations, some optimistic and others pessimistic. It shows that the current code equations lead to very significant errors on either side of conservatism, while the proposed equation is consistently accurate for all test specimens known to fail in shear-out. A resistance factor of 0.85 is recommended for the proposed equation in order to achieve a reliability index of 4.0. The use of the proposed equation instead of the current AISC specification's equation will facilitate structural designs that are more economical yet reliable.

Shear-Out Capacity of Bolted Connections in Cold-Reduced Steel Sheets

“…However, these equations differ not only in coefficients but also in variables, and always overestimate or underestimate the shear-out capacity of the bolted connection. Teh and Uz (2015) have shown that the shear-out capacity given by the North American cold-formed steel specification is too conservative for hot-rolled steel bolted connections, but it is uncertain whether the same outcome applies to cold-reduced sheet steel connections as the latter often have reduced material ductility. To the authors' knowledge, the European and Australian shear-out provisions have never been checked against cold-reduced sheet steel connections since they were adopted from the respective provisions for hot-rolled steel connections.…”

“…Equation 8has been demonstrated by Teh and Uz (2015) to be accurate for hotrolled steel specimens tested by independent researchers. The use of the effective shear planes depicted in Figure 2.2 has also been comprehensively validated by Elliott et al (2019) through finite element analysis incorporating shear fracture simulation.…”

“…Equations proposed by researchers are also discussed. It is shown that current Specifications cannot accurately predict the shear-out capacity of a bolted connection in cold-reduced steel sheet; even thoughTeh and Uz (2015) have already figured out the mechanism of shear-out failure and proposed an equation which is shown to be accurate for structural steel. An equation is still needed to predict the shear-out capacity of bolted connections in cold-reduced steel sheets.…”

“…The primary purpose of the experimental program is to assess the accuracy of the current shear-out equations for cold-formed steel sheets in Section J6.1 of the North American Specification for the Design of Cold-formed Steel Structural Members 2016 (AISI 2016); inTable 7.4 of the European codeEN-1993-1-3:2006 (ECS 2006; and in Clause 5.2.4.3 of the Australian/New Zealand standard AS/NZS 4600:2018 (SA/SNZ 2018); or Equations 1, 3 and 2 respectively in this thesis.The literature review showed that the actual shear plane is the subject of argument by researchers and differs in the specifications of different countries. The active shear plane was proposed byTeh and Uz (2015) in their study of bolted connections failed by shear. Test results can also verify the actual location of the shear plane.The experimental program consisted of 71 tests, 60 of them failed by shear-out.The tests comprised four nominal bolt diameters, three edge distances, five ratios of end distance to bolt diameter, three thicknesses, two end cutting methods and two sheet steel grades of very different ductility.…”

Combined Bearing and Shear-Out Capacity of Structural Steel Bolted Connections

“…The shear-out data 251 encompass those presented by Teh & Uz (2015a), while the rest can be found in Tables 2 and 252 3. It can be seen that the authors' equations are significantly more consistent and more 253 accurate than the current AISC equations (AISC 2010(AISC , 2015.…”