Multi-storey Steel Frame Residential Structure System By The Mechanical Properties And Second Order Effects Impact Analysis

Along with the rapid development of finance and enhancement of our national power of China, emerges sharp promotion in the steel industry. Since 1996, the average steel output is a hundred million ton per year. It has reached to two hundred million tons per year by 2003, and became the top one in the world. But the proportion of steel usage in architecture is quite small. As one of the three main industry of China, it seems very unreasonable. Therefore, the related ministries and commissions set up a series of policy to increase the steel usage in architecture.Currently, two structure systems are usually used in the multistory house in China, steel frames and steel braced frames. These systems have a great deal of advantages, such as high strength, light deadweight, good earthquake-resistant performance, smaller structural element dimension, fast construction in speed, of favor to environmental protection.In order to meet with the development of resident steel structure in our country, in this paper, the Chinese seismic code for buildings and the research achievement home and abroad are combined. And by the calculation of instances, the characteristics of the static and dynamic behaviors of the steel frames are obtained. Then some practical suggestions are offered for better applications of these structural systems.In this paper, an analysis of steel frame structures is performed by use of the first-order analysis, the second-order analysis and the approximate second-order analysis recommended in Code for design of Steel Structures (GB50017-2003). From the comparison of calculated results, some general conclusions are drawn for steel frame structural analysis considering the second-order effect.P-Delta effects play an important role in the response of steel frame structures to lateral loads such as those generated in earthquake. They are defined as the amplification of shear forces and bending moments in structural members induced by gravity loads acting on the laterally displaced building frame. Elastic stiffness of a structure is reduced by P-Delta effects which leads to an increase in drift. When columns are pushed into the inelastic range P-Delta effects may cause significant amplification in drift compared to results obtained from elastic P-Delta analysis. In this paper nonlinear analysis approach for design of steel frames are presented. In addition, the consideration of nonlinear factors influencing the global ultimate capacity of steel frames is discussed. The achievements on nonlinear analysis have formed a foundation for the advanced design of steel frames.