Mechanical Properties of Single Shear Plane of Bolted Steel Connection

Abstract

Abstract A 5-storey portable steel tower based on prefabricated frame concept has been built in Jamilus Research Centre, UTHM. It is now undergoing laboratory testing for static and dynamic performance. In this study, the mechanical properties of the connections were investigated via their connection condition between elements (beam and column) and connectors. The frame elements were designed based on S275 steel grade of 77 mm x 77 mm hollow section with 3 mm thickness, and 8 mm thickness of connectors’ plate. The connection was subjected to single shear plane action which fastened by bolts. Mild steel (grade 4.6) and high tension (grade 8.8) bolts with 10 mm diameter size were used. Shear, bearing and tensile strengths of the bolts and steel plates were determined via tension testing using 50 tonnes of Universal Testing Machine (UTM). From the results, all bolts and steel plates have satisfied the design strengths requirement of 640 N/mm2 (high tension bolt), 240 N/mm2 (mild steel bolt) and 275 N/mm2 as required by EN 1993-1-8. Meanwhile the ultimate shear force of bolts was found within ranges of 25% (high tension) and 12.5% (mild steel) from their respective ultimate tensile force. Bearing failure was occurred at bolt hole of 3 mm thickness of steel plate but only when it was fastened to high tension bolt. No bearing failure occurred when mild steel bolt was used. It has proven that all bolt spacing and edges distances were sufficient, without tearing failure observed in all testing. Finally, the permissible bearing resistance were checked based on the ratio of experiment against the EN 1993-1-8 relationships, when it has shown to satisfaction if the value is less than 1 as recommended by previous researcher.