FINITE ELEMENT SIMULATION ANALYSIS ON STRENGTHENING OF REINFORCED CONCRETE COLUMNS WITH DIFFERENT KINDS OF FRP SHEETS

The purpose of this paper is to develop choosing standards of FRP sheets, best methods of seismic strengthening and the corresponding theory of strengthening for reinforced concrete columns. Therefore, two-dimensional nonlinear finite element numerical simulations on seismic strengthening of RC columns with 4-type of axial force ratio are carried out, in which the types and the amount (i.e. FRPs stiffness) of FRP sheets are chosen as parameters and the stress-strain curve of confined concrete from FRP and hoops is considered through adopting modified Kent-Park model. Numerical investigation on loading characteristics of RC columns and its retrofitting effectiveness of seismic performance with different types and amount of FRP sheets are performed. Simultaneously, the effects of axial force ratio on the load-deformation relationships of RC columns are discussed. What’s more, the failure modes of RC columns are discussed based on the loading characteristics. Lastly, the theory on seismic strengthening of RC column with FRP sheets is provided