FRP-confined concrete model based on damage-plasticity and phase-field approaches

This paper is concerned with the finite element (FE) modeling of mechanical behavior for concrete columns wrapped with fiber reinforced polymer (FRP) materials under uniform compression load. The introduced model is based on modifying damage evolution in concrete and FRP considered as a brittle material. In this work, the Miehe phase-field approach is employed for capturing the damage in the FRP, whereas the damage in concrete is evaluated by introducing an extension of the simplified damage formulation based on the Miehe phase-field model. One of the most advantages of the proposed model is that the ultimate condition is automatically imposed in the FE model, and there is no longer required any additional ad hoc criteria that consider in the previous models to evaluate the ultimate conditions. As the brittle material behavior, the simulation results show that the damage of the specimen under compression load at the final steps is rapidly developed and is significant. Moreover, the force-displacement curves are in good agreement with the experimental tests.