Analysis of steel and composite braced frames with semi-rigid joints

Abstract

One of the recommended structural systems for multi-storey buildings is such, where composite technologies are used, for example, steel skeleton combined with concrete slabs. Such a system has the following advantages: it allows the reduction of the construction time, composite members can be made slender and at the same time stiff and strong, semi-rigid joints can be used which leads to cheaper connections, and it reduces steel consumption. The objective of the chapter is to present an analysis of savings in steel consumptions, resulting from the usage of semi-rigid joints. To analyze the influence of joint parameters on frame economy, it is not enough to focus on moment distribution; one should also focus on the results of frame elements dimensioning, according to limit states. In the chapter, results of analysis of few steel and composite braced frames are presented. During analysis, frame structural elements (beam and columns) sections are changed according to changes of internal forced caused by joint stiffness changes. Efficiency of composite steel-concrete floors in the framework of buildings as well as economy confirmation of using semi-rigid joints in braced steel and composite structures is demonstrated in the chapter.