Eccentric Compression Behavior Of Elliptical Concrete-Filled Steel Tubular Slender Columns

Aimed to the research and application of the concrete filled steel tube, especially new concrete filled steel tube structure forms, eccentric compression behavior of elliptical concrete-filled steel tubular slender columns under eccentric compression were investigated in this paper. Based on the systematic analysis of the experiment and theory, and the existing research results of eccentric compression behavior of elliptical concrete-filled steel tubular slender columns, practical calculating methods for loading bearing capacity of elliptical concrete-filled steel tubular slender columns under eccentric compression were suggested.The main research works were summarized in detail as follows:Ten elliptical concrete-filled steel tubular slender columns were tested systematically. The influence of slenderness ratio, eccentric distance, concrete (whether filled or not) on bearing capacity, initial rigidity and failure modes were investigated, and then, the mechanical properties of elliptical concrete-filled steel tubular slender columns were evaluated.The finite element analysis models corresponding to the tests were developed by nonlinear finite element software ABAQUS. By comparison, the predicted results are in good agreement with the measured results. And then, the veracity of the finite element analogy was demonstrated. The further finite element analysis using ABAQUS was carried out. The main parameters influence on the mechanical properties of elliptical concrete-filled steel tubular slender columns such as slenderness ratio, concrete strength, steel tube yield strength, steel tube thickness, eccentric distance were further analyzed.The practical calculated methods on compression bearing capacity of elliptical concrete-filled steel tubular slender columns subjected to eccentric compression were suggested. The results calculated by the calculated method are in good agreement with the results of finite element models and the tests. The consequence indicates that the calculated method is reliable and applicable.