Research On Behaviors Of Hybrid CFRP-Concrete-Steel Double-Skin Tubular Columns

Over the past decade, the theory and practice of confined concrete develops and maturates basing on the research and exploiture of steel tube confined concrete and FRP confined concrete. The sustainble development of construction of the world in civil engineering makes new materials,new structures and new techniques perpetual exploiture and application. The new hybrid FRP-concrete-steel double skin tubular columns(HFDSTC) is developing on this backgroud.Nonlinear finite element analysis software ABAQUS will be used in this thesis to do some axial compression behavior analysis of HFDSTC basing on the studied results of concrete filled steel tubular columns,concrete-filled double skin steel tubular columns and FRP constrainted concrete columns. Totally speaking, the thesis includes the following parts:Appropriate elements types, meterial models and failure rules are selected and the geometry parameters and material parameters that Teng used in the HFDSTC tests are used to analyze by finite element method basing on the behaviors of the hybrid columns and its interactive effects mechanics. From the figues of principal stress vectors, we can see that the stress-resisted characteristic of each part of hybrid columns accord to theory analysis, and compare finite element results to test results, the comparison indicates that the finite element model of HFDSTC proposed in this thesis is feasible t for the analysis of axial compression behavior on hybrid columns.The axial compression behaviors of hybrid columns are analyzed. The analysis consider the effects of cross sections, the thickness and modulus of wrapped CFRP, the thickness and strength of inner steel tube and the strength rank of concrete on the behavior of hybrid columns, the analysis are mainly on CC cross section columns. they are not only on the analysis of axial load-vertical displacement behaviors, but also to analyze the stress distribution along radial direction of concrete, the deformation behaviors of hybrid columns, stress devoloping rules for steel tube and CFRP of CC columns. The effects of mid hollow cross section and the effects of fillet on RR cross section hybrid...