Ultimate strength analysis of composite plane frames

摘要

The composite frames, usually consisting of steel columns and composite beams, have become an economical and efficient load-bearing system in high-rise and multi-story buildings partially due to their higher stiffness and strength than the bre steel frames. Because the composite frames arec composed of three types of materials of concrete, reinforcement and steel, the linear elastic analysis can be carried out by equivalent stiffness method. Since the concrete cracking due to tension and crushing due to compression, in addition to the steel yielding, should be considered in the ultimate strength analysis. The nonlinear elastic/plastic analysis becomes much more complicated, is usually solved by two dimensional elements. In this paper a simplified finite element model is proposed to allow the ultimate strength analysis of composite frames with relative ease. The analysis procedure is compared with numerical examples and experimental results.