Plasticity modeling of FRP-confined circular reinforced concrete columns subjected to eccentric axial loading

This paper presents a numerical study on FRP-wrap strengthened reinforced concrete columns subjected to eccentric axial loads using ABAQUS®. For modeling of concrete dilation under non-uniform confinement pressure, a smooth cap plasticity model was combined with concrete damaged plasticity model. This model includes different concrete compaction–dilation behaviors which is pressure-dependent. Proposed model has been calibrated and verified for concrete in number of unconfined and full-wrapped columns under combination of axial force and bending moment. Presented numerical predictions are shown to be in close agreement with existing experimental results. The effect of laminate stacking sequences and column slenderness on strength and ductility of members was examined thoroughly. The results of this study recommend taking fiber angles between zero (circumferential) and 30° can improve ultimate strength and ductility of confined short concrete columns. However, for slender concrete columns the optimum fiber orientation can be set between 15° and 30°.