Fem analysis for hysteretic behavior of thin-walled stiffened rectangular steel columns with in-filled concrete

CFT columns used as bridge piers have high strength and ductility, compared with hollow columns. However, up to the present, no sufficient research has been conducted on an accurate analysis of concrete-filled stiffened rectangular steel columns under cyclic load. Herein, based on ABAQUS, an accurate and numerically stable 3-D FE model is proposed with considering the geometric and material nonlinearity as well as the interface action between in-filled concrete and steel tube. The validity of the computed hysteretic behavior of CFT columns is confirmed by existing experimental results. Based on the proposed FE model, the local buckling restraining effect, the distribution of confining pressure from steel tube, the enhancement in axial compressive strength of in-filled concrete and the metal fracture of steel tube are discussed in detail.