Nonlinear 3D finite element simulation of CFST columns under different confined concrete material’s models

Nowadays everything expands rapidly and growth with time, including the service structures to accommodate an acceptable level of service to the community. The concrete filled steel tubes is a new technique that provides some features compared with the normal concrete columns.in this study three concrete compressive stress strain models behavior have been studied to validate the adopted experimental work and find the best model that can simulate the actual data, using nonlinear finite element analysis in Abaqus. Then, three type of concrete strength where considered (C25, C40, and C60) with three Diameter of tube thickness ratios are; 165,100, and 50 for each concrete class type. Tests results have shown that the confinement effect in high strength concrete was higher than other types of concrete types, in addition to a noticeable enhancement in the ductility behavior. The adopted model was able to capture concrete compressive behavior accurately, for all curve’s stages