Finite Element Modeling of Debonding Failures in FRP-Strengthened Concrete Beams Using Cohesive Zone Model

Abstract

Intermediate crack (IC) debonding and concrete cover separation (CCS) are common types of debonding failures in concrete beams flexurally strengthened with fiber-reinforced polymer (FRP) composites. In this paper, a three-dimensional finite element (FE) model was developed to simulate the flexural behavior and predict the critical debonding failure in FRP-strengthened beams. The two critical debonding failures were considered in the FE model by implementing a cohesive zone model based on fracture mechanics considering the effect of the related parameters. The input values used for the cohesive zone model are modified in this study to obtain accurate and consistent predictions. The FE model was validated by comparison with experimental results tested by the authors for beams particularly prone to fail by either of the two critical debonding failures. The results obtained from the FE model agree well with the experimental results for both of the debonding failures and the corresponding capacities at failure. In general, the ratio of the experimental to numerical ultimate capacities was within 5%, and so was the ratio of the experimental to numerical mid-span deflections at debonding failures. The FE model developed in this study was then used to conduct a parametric study investigating the effect of shear span-to-depth ratio and spacing of steel stirrups on the ultimate capacity and type of debonding failure in FRP-strengthened beams. The results of the parametric study revealed that increasing the spacing of steel stirrups caused a significant decrease in the load capacity at concrete cover separation failure. In addition, varying the shear span-to-depth ratio was seen to have an important effect on the type of debonding failure and corresponding capacities for the FRP-strengthened beams having the same cross-section geometry and CFRP reinforcement.

Theoretical and Experimental Substantiation of the Efficiency of Combined-Reinforced Glass Fiber Polymer Composite Concrete Elements in Bending

“…Finally, from a price point of view, the cost of our elements is reduced and is more economical, as confirmed by our economic analysis. This is in good agreement with the results of the authors [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]35,[37][38][39][40][41][42][43][44][45][46][47][48][49][50].…”

“…Finally, the works of the authors involved in the study of polymer composite concrete bending elements (beams) [2,5,8,[11][12][13]15,16,35,[37][38][39][40][41][42][43][44][45][46][47][48][49][50] were of particular interest for the development of this study. To improve the performance of bending elements, researchers studied the following for their reinforcement: fiber-reinforced polymers (FRP), glassreinforced polymers (GFRP), composite polymers, reinforcement with jute-polyester fiber (JPFRP), polymers, reinforcement with basalt fiber (BFRP), carbon (CFRP) and aramid (AFRP) fibers.…”

Analytical and Numerical Investigation of the Behavior of Engineered Cementitious Composite Members under Shear Loads

“…Next, the element type in ABAQUS controls the element characteristics of the mesh. For mesh control and the type of mesh, hexahedron element and structured meshing, respectively, were selected because the geometry of the element used in modeling the beam specimens was not complex [38,39]. The ECC beam that was meshed is presented in Figure 7.…”

Computational Investigation of the Mechanical Behavior of a Bone-Inspired Nanocomposite Material

“…The interfaces in these materials play a significant role in determining their material properties. The cohesive zone model (CZM) is widely used to describe and analyze the damage mode of material interface during the failure process [32][33][34][35][36][37]. The CZM has proven to be highly effective in capturing the intricate interactions between different material phases and predicting the initiation and propagation of cracks, debonding, and other failure mechanisms.…”