Numerical Analysis of Interface Crack Propagation in Reinforced Concrete Beams Strengthened with FRP by Extended Isoparametric Finite Element Method

Extended isoparametric finite method (XIFEM) consists in enriching the basis of the classical finite element method and taking into account the discontinuity of the displacement field across the crack by a discontinuous function along the crack line. It simulates the discontinuous character resulted from discontinuity such as crack or joint and by some trigonometric basis functions around the crack tip to embody singularity at the end of discontinuity. With the improved XIFEM, the tracking of crack propagation in reinforced concrete beams strengthened with FRP is simulated and the failure model is analyzed. Compared with the traditional finite element method, the XIFEM allows crack surface to be in any position of finite element mesh without dense mesh near the crack tips and without re-meshing, therefore crack growth is traced and modeled effectively. The results show the effectiveness and superiority of the improved XIFEM.