Finite Element Modeling of Fiber-Reinforced Polymer Composite Tubes Filled with Concrete

Sustainable development of Civil Engineering infrastructure has already benefited from the use of fiber-reinforced polymer (FRP) composite materials for different structural applications such as reinforcing existing structures and constructing new ones. Among the various FRP structural elements, ± 55° filament wound glass FRP (GFRP) tubes, which are typically prefabricated for piping application, have been considered in a number of structural applications. As a load-bearing structural element, filling these tubes with concrete (concrete-filled FRP tubes or CFFTs) can considerably enhance their stiffness and strength under axial and flexural loadings. Although there have been multiple studies on the bending and compressive behavior of CFFTs, studies on the tensile behavior of CFFTs and especially those made of ± 55° GFRP tubes are quite scarce. Here in this study, in order to take a step toward a better understanding of the behavior of the CFFTs under axial tension, finite element models of the hollow tubes and CFFTs were generated using the ABAQUS software package and verified against the experimental outputs of previous studies. Shell elements were used to model the tube while solid elements formed the concrete. The concrete damaged plasticity (CDP) model was used to introduce the material properties of the concrete to the model. Quasi-static analysis using Dynamic/Explicit solver was implemented due to its capabilities for converging highly nonlinear problems. Good compatibility of the results of the numerical study with the test outputs was seen on both hollow tubes and CFFTs. It can be concluded that the damage criteria used for FRP were capable of predicting matrix cracking as the governing mode of failure in FRP observed in the experiments. Moreover, the CDP model could simulate the tensile cracking of concrete.