Improved design shear method of the bolted cold-formed steel clip-angle for serviceability: Fid-Bau Portal

Improved design shear method of the bolted cold-formed steel clip-angle for serviceability

Mallepogu, Nagaraju / Madhavan, Mahendrakumar

Abstract This paper presents an experimental investigation on the three-bolted clip-angle (CA) connector under direct shear load. A total of 48 clip-angle connection tests were carried out with 27 different clip-angle configurations by varying the thickness, width and depth of the clip-angle. The present experimental results and the data from literature indicates that the existing design methods for the service limit state design of the clip-angle are inefficient. The present investigation proposes a novel and efficient design method for the service limit state after calibration against test data, for the low-grade steel clip-angle ( $f_{y} = 271 MPa$ to 307 MPa) from the present research work and for the higher grade steel ( $f_{y} = 375 MPa$ to 550 MPa) from the literature data. Hence the proposed design method has wider steel grade application from $f_{y} = 271 MPa$ to 550 MPa. Parametric studies were performed to evaluate the influence of the geometric variables on the service shear strength of the three bolted clip-angle. The proposed design method was also applied to the welded clip-angle configuration in the literature and corresponding design equations were developed. In addition, a comparative study between the present three-bolted and most recent welded clip-angle connection was conducted which indicated that the three-bolted clip-angle configuration has higher stiffness than that of the welded configuration. Reliability studies were performed and relevant design factors were determined according to the LRFD, LSD and ASD methods.

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Highlights • A novel design method is proposed for the service shear strength of three bolted clip-angle through laboratory tests. • Effect of thickness, width and depth on service shear strength was investigated. • Suggested design method applicable and efficient for the welded clip-angle as well. • Three bolted clip-angle attains high shear strength than the welded clip-angle. • Design factors were suggested for LRFD, LSD and ASD methods from reliability analysis.