The Behavior Research On The Lateral Resistant System Of Steel Frame And Connection

Many achievements have made in the research and application of structural steel since almost one hundred years ago. Structural steel has been widely used in the residential building abroad for many years, but it just begins to be adopted in the residential building domestic since recent years. Technically, steel residential building system must accord with the characteristics of residential building and the development of residential industrialization. There are still many problems remain to be solved in these aspects, such as behavior research on the lateral resistant of steel frame and connection etc. In this paper three 1:2-scale steel frame specimens and eight full-scale steel frame connection specimens are tested on their behavior under cycle loading. There are six aspects as below on the problems of steel resident building researched:1 Pseudo-static force testing of eight full-scale connections, including top-seat angle connections, two web flange and top-seat connections and dog-bone connections are carried out for the first time in our country. The relations of M- r ,initial stiffness ,the yield strength, failure models, ultimate strength, seismic behaviors and characteristic of dissipation of energy were gained in this test.2 The Dog-bone moment connections are considered having excellent performance for seismic resistance in steel frame and can avoid the brittle failure happening to the connections effectively. This paper describes experimental studies and finite element analysis that examined the hysteresis characteristics of dog-bone connection and steel frame. It is proved that the connection and steel frame with beam flange dog-bone reduced have superior behavior to the frame of conventional design and the brittle failure is avoided in the steel frame.and conditions of stress development in the dog-bone, and the reason of the brittle failure in the rigid connections is obtained. It is emphasized that the weld quality of the seal in beam-column connections is very important for the function of dog-bone reduced beam flange and must be paid more attention.3 A simply analysis method, which could be used to analyze the moment -rotation behavior of angle connections, is presented in this paper. Apoly-linear moment-rotation model is calculated according to this method, which could represent the moment-rotation relation of two kinds of angle connection. This model is implemented into a finite element analysis on the experimental steel frame and the results agree well with experimental results. At the same time discuss the influence of different connections to the behavior of the steel structure.4 Pseudo-static force testing of 1:2 scale models including three steel frame two with semi-rigid connection and one with dog-bone connection are first carried out in china in order to obtain elastic-plastic behavior of semi-rigid connections and dog-bone connections steel frames under cyclic loading as well as to analyze collapse characteristic and the coming order of plastic hinges of the structure with different connections after structural ultimate strength has lost and conditions of stress development in the dog-bone, and the reason of the brittle failure in the rigid connections is obtained.5 With the numerical technology adopted to reinforce experimental research, different elements are considered in the nonlinear analysis on steel frame according to different mechanics characteristics. The calculation results not only agree reasonably with experimental result, but also show some important phenomena which didn't obtained during the experiment.Some problems about this research worth to be studied afterward are put up in the end of the paper.