Finite Element Analysis of Concrete Columns Confined with FRP Sheets

A nonlinear finite element model is developed for the analysis of plain and reinforced concrete column confined by FRP sheets. The column sections chosen for the analysis are either circular or square in shape. The behavior of small and large scale FRP wrapped concrete columns under uni-axial compression is investigated using the developed model. The proposed FEA model is based on appropriate selection of elements, strength failure criteria and other parameters required for accurate analysis of concrete columns confined with FRP sheets. The model is validated with some published results on FEA and experimentation. A detail parametric study is done to quantify the effect of the thickness, stiffness and fiber orientation of the FRP sheets as well as unconfined concrete strength on confinement and stiffness of the strengthened columns using the proposed model. Based on the present analysis results, accurate stress distribution in concrete and FRP is also obtained which improves understanding of the confinement mechanism of the concrete columns.