Finite Element Modeling for RC Hollow Columns Wrapped with FRP Laminates
A finite element reinforced concrete model has been analyzed by the author with Ansys v.9 finite element program for both unstrengthened and CFRP-strengthened hollow columns using solid65 concrete element, its size 24x26x24 mm and Link8 discrete steel distribution element. The CFRP has been modeled using Solid46 element, which has orthotropic properties. The deflection results have been compared with an experimental and other finite element model which are performed by Lignola , in which using Tno Diana v. 9.1 finite element program for modeling concrete using three-dimensional solid brick element type Chx60, steel using embedded reinforcement truss element and CFRP using three-node plane bonded element. These results show that the author's model is much better than the Lignola's  model comparing with the experimental one. A parametric study has been done on the proposed model for obtaining the effect of using the GFRP instead of the CFRP in column strengthening by comparing the failure loads and the concrete and steel properties at failure. This study show a reduction in the failure load values by an amount 0.6 to 2.8% when using GFRP, indicating that the CFRP is more preferable in strengthening of the hollow column than the GFRP.
Dongye Sun, Wen-Pei Sung and Ran Chen
A. M. Mahmoud "Finite Element Modeling for RC Hollow Columns Wrapped with FRP Laminates", Applied Mechanics and Materials, Vols. 71-78, pp. 3347-3353, 2011