Performance of partially compressed CFST columns through dissimilarly shaped bearing plates under axial load

Previously, the authors and other researchers have reported experimental and numerical investigations on partially compressed concrete-filled steel tube (CFST) columns. However, the main focus of available studies was laid on the cases where both the bearing plate and the column had the same cross-sectional shape. The performance of CFST columns compressed partially through dissimilarly shaped bearing plates remains unknown, which is therefore addressed in this paper. Twenty-eight partially compressed CFST column specimens and another two reference entirely compressed ones were tested under axial load, based on which the failure patterns, load versus deformation curves and bearing capacity were obtained and discussed. The performance of specimens compressed through the same and dissimilarly shaped bearing plates was analyzed and compared. Furthermore, numerical simulation on the behaviour of partially compressed CFST columns under axial load was performed using finite element analysis (FEA) model, the feasibility of which was verified by the experimental results. Extended parametric analysis was further carried out in accordance to the FEA model to study the impacts of typical factors on the structural behaviour. Finally, design methods for the bearing capacity of partially compressed CFST columns through the same and dissimilarly shaped bearing plates under axial load were recommended and valuated. The primary difference between the present work and the author's previous studies is the performance comparison study of the partially compressed CFST columns through the same and dissimilarly shaped bearing plates under axial load using the experimental and theoretical method, which is essential for the practical design of these particular conditions.