Calibrations of Bolted Cold-formed Steel Connections in Bearing (With and Without Washers)

Abstract

The bearing strength of bolted connections is treated differently in the two current North American Cold-Formed Steel Design documents, the AISI Specification in the USA (AISI 1996a) and the S136 Standard in Canada (CSA 1994). In the case of the S136 Standard (CSA 1994), only one expression is presented that applies to all bolted connections such as single and double shear, as well as, with and without washers. In the AISI Specification (AISI 1996a), however, a distinction is made between single shear and double shear connections and the use of washers. Contained in this paper are the calibration results of single and double shear cold-formed steel bolted connections with and without washers that failed in bearing. Calibrations were carried out in accordance with the AISI Commentary (AISI 1996b) to establish the resistance factors and respective factor of safety, which have already been adopted by the North American Specification (NAS 2001). 1.0 Introduction The bearing strength of bolted connections is treated differently in the two current North American Cold-Formed Steel Design documents, the AISI Specification in the USA (AISI 1996a) and the S136 Standard in Canada (CSA 1994). In the case of the S136 Standard (CSA 1994), only one expression is presented that applies to all bolted connections such as single and double shear, as well as, with and without washers. In the AISI Specification (AISI 1996a), however, a distinction is made between single shear and double shear connections and the use of washers. More specifically, the following two categories are presented, with and without washers: 1) Inside sheet of double shear connection and 2) Single shear and outside sheet of double shear connection. 1 Graduate student, Department of Civil Engineering, University of Waterloo, Waterloo, Ontario, Canada. 2 Professor of Structural Engineering, Department of Civil Engineering, University of Waterloo, Waterloo, Ontario, Canada. 3 Professor of Civil Engineering, University of Missouri-Rolla, Rolla, Missouri, USA. 851