X-type RHS Concrete Compression Node Ultimate Bearing Capacity

This paper is part of the research project entitled "Behavior and Design MethodStudies of the Concrete-filled Steel Tubular Connections" supported by the HunanProvincial Natural Scientific Research Fund , and focuses on the ultimate capacityof concrete-filled square steel tubular (CFST) compression-loaded X-connection.This paper consists of four chapters.In chapter 1, state-of-the-art status at home and abroad on concrete-filled steeltubular is reviewed, its character and practical application are introduced, and thisresearch is outlined. In chapter 2, work mechanism of CFST compression-loadedX-connections is discussed. In accordance with investigation into ultimate capacityof concrete in chord and chord web, the theoretical formula predicting the ultimatecapacity of CFST compression-loaded X-connections is proposed. In chapter 3,through the analysis of the experimental results, the main factors that affectultimate capacity of CFST compression-loaded X-corinections are investigated, andthe practical formula of CFST compression-loaded X-connections is obtained. Theresults obtained by the proposed formula are in agreement with the experiments. Thelast chapter is the summary for the whole paper.