Mechanical Performance Analysis Of Cover-plate Reinforced Dog-bone Connection In Steel Frame

Steel structure has feature of high strength, light weight, uniform material, good plastic deformation and tenacity, easy manufacturing and construction, which make it become more generally preferred in seismic design of buildings. At present, it has been widely adopted in plants, bridges, large-sized industrial equipment and building construction.However, the property of steel structure isn’t perfect. For example, the 1994 Northridge Earthquake of magnitude 6.6 and the 1995 Kobe Earthquake of magnitude 7.3, results in great losses of life and property in the reason of seriously damaged welded joint. Later then, American researchers proposed some methods to improve the beam-column welded joint after studying it’s situation in the earthquake. The main strategy is shift-away of plastic hinge(to move the plastic hinge outward from the beam-column interface). To realize that, there are two different ways. One is to reduce the beam sections, another is to reinforce the end of section beam by some construction methods.On the basis of this idea, the paper discussed synthetically the two theories, that is reducing the beam flange and reinforcing the cover-plate properly so that to realize shift-away of plastic hinge and keep strong bearing capacity, great ductility and energy consumption. This paper uses finite element analysis and ABAQUS program to analyze the mechanical properties(hereafter called cover-plate reinforced dog bone type node), it also studies the rules of the length and depth of weakened beam flange and cover-plate influencing the earthquake resistant performance. Then it concludes reasonable seismic design data, and gives some reliable proposal in practical engineering application. In the end, this paper designs a cover-plate reinforced dag-bone connection, a cover-plate reinforced connection and a reduced beam connection, and compares the weakness and strengthness of them.