Seismic Design and Tests of Bolted Shear-Tab Connections and Steel Moment Connections

Abstract

In this study full-scale tests were first conducted on two steel H-beam-to-box-column connections with bolted-web-and-welded-flange (BWWF) details One connection reflects the design practice in Taiwan and the other exams the retrofit scheme of adding another shear tab and high-strength bolts The shear tabs were designed to have moment capacity more than the beam webs Slip strength of high-strength bolts were used in the design of the bolted web connections Both the connections were tested under the AISC 2016 loading protocol and sustained a drift angle of 4% The strain guage measurement indicates that high-strength bolts slip and lose the pretension even at a small drift angle like 0 375% That also shows that bolted web connections share moment and the moment ratio changes with the connection behavior In detail the moment ratio and bolt pretension drop to the minimum when the connections strat to have plastic behavior at a drift anlge of 1% As the connections sustain greater drift angles stress redistribution causes the moment ratio to increase The techniques of FEA were then applied to study design paramters The result shows that the increase in plate thickness of shear tabs can effectively reduce the equivalent plastic strain (PEEQ value) and von Mise stress at the root of a weld access hole and base metal surrounding the beam flange groove welds In contrast bolt arrangement and strength and shapes of weld access holes can affect but to a limited extent

Date of Award	2019
Original language	English
Supervisor	Chi-ming Lai (Supervisor)