Behavior Of Conical Concrete-filled Double-skin Steel Tubular Stub Columns With Endplate Under Axial Partial Compression

Aimed to the research and application of the concrete filled steel tube, especially newconcrete filled steel tube structure forms, mechanical properties of conical concrete-filleddouble-skin steel tubular stub columns with endplate under axial partial compression wereinvestigated in this paper. Based on the systematic analysis of the experiment and theory, and theexisting research results of concrete-filled double-skin steel tubular stub columns and commonconcrete filled steel tubular stub columns, practical calculating methods for loading bearingcapacity of conical concrete-filled double-skin steel tubular stub columns with endplate underaxial partial compression were suggested.The main research works were summarized in detail as follows:Fourteen conical concrete-filled double-skin steel tubular stub columns and two conicaldouble-skin steel tubular stub columns were tested systematically.The influence of taper, rigidityof endplate and axial partial compression ratio on bearing capacity, ductility and failure modeswere investigated, and then, the mechanical properties of conical concrete-filled double-skinsteel tubular stub columns were evaluated.The finite element analysis models corresponding to the tests were developed by nonlinearfinite element software ABAQUS. By comparison, the predicted results are in good agreenmentwith 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 parametersinfluence on the mechanical properties of conical concrete-filled double-skin steel tubular stubcolumns such as taper, strength of the materials，hollow ratio, axial partial compression ratio andrigidity of endplate were further analysed.The practical calculated method on compression bearing capacity of conical concrete-filleddouble-skin steel tubular stub columns subjected to axial partial compression were suggested.The results calculated by the calculated method are in good agreenment with the results of finiteelement models and the tests.The consequence indicates that the calculated method is reliableand practical.