| With the development of urbanization process in China,population and wealth are increasingly concentrated.In the event of a rare earthquake,the destruction or even collapse of structures will cause serious economic losses and lots of injuries and deaths.The interruption of the use of buildings after earthquakes will further aggravate the losses,and may lead to the interruption of the industrial chain and the occurrence of serious secondary disasters.It's particularly important to improve the city's anti-earthquake capability and achieve rapid recovery of structures,especially important buildings after a rare earthquake.Therefore,it is necessary to explore a new structural system to achieve low-damage or even no damage of major members and to ensure the rapid recovery of the function.In the paper,aiming at the new high strength steel frame structural system with damage-control fuses,the weld performance,the damage-control effect and the slab effect are studied by using the experimental method and the finite element simulation.The main research of this paper are as follows:(1)The research status of earthquake-resilient structures and the development trends of material properties,welding technology and engineering application about high strength steel are summarized.And the composition and characteristics of the proposed high strength steel frame structural system with damage-control fuses are introduced.(2)The seismic behavior of the welded high strength steel beam-column connections is studied.The full-scale quasi-static reciprocating tests of a ordinary steel beam-column connection and three high strength steel beam-column connections using traditional welded joints are carried out to investigate the seismic behavior and construction methods of high strength steel beam-column connections.The effect of different loading protocols on their mechanical properties are analyzed.Besides,the connection forms and welding technology suitable for high strength steel beam-column connections are proposed.(3)The damage mechanism of the high strength beam-column connection is studied by using the detailed finite element models and parameter analysis.The existing research on the proposed high strength steel frame structural system is summarized.Based on the specimens in the existing research,the detailed finite element models are carried out and verified by the test results.The verified models are used to perform a parametric study.The parameters include the width of the gap between two neighboring I-beams at the fuse position,the slenderness ratio of the fuse,the strength of the fuse,the loading protocols and the pre-arching distance at the middle region of the fuse.According to the parametric study,the design parameters of the fuse are optimized.(4)The seismic behavior and working mechanism of the damage-control fuses for the high strength steel beam-column connections with slabs are studied by the full-scale quasi-static tests.The full-scale quasi-static tests of a high strength steel beam-column connections using fuses without slabs and four high strength steel beam-column connections using fuses with slabs are carried out to investigate the slab effect on the mechanical mechanism and seismic performance,and the design suggestions for the fuses with slabs are proposed.(5)On the basis of full-scale tests,the detailed finite element models of the specimens with slabs and fuses and the specimens without slabs are established.The details of failure process of high-strength steel beam-to-column joints with fuses under slab effect are given,and the mechanical mechanism of the specimens is further analyzed and verified. |
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