Prediction of the behavior of retrofitted concrete beams and laminated plates using micromechanical constitutive models

Abstract

A series of numerical simulations are conducted to predict the behavior of shear deficient concrete beams strengthened with repair systems and laminated plates containing a cutout. In Chapter 2, a numerical study is conducted to evaluate the shear strengthening performance of two composite repair systems, FRP strips and a sprayed epoxy coating. Micromechanical constitutive models for the FRP strips and sprayed epoxy coating proposed by Liang et al. (2006), Lee et al. (2005) and Lee and Simunovic (2000), in conjunction with damage models, are implemented into the finite element program ABAQUS to solve boundary value problems. Using the implemented models, numerical simulations of four-point bending tests on concrete beams strengthened with the external repair systems are conducted to quantify their strengthening abilities. The numerical tests yield load-deflection curves from which the shear strengthening performance of the external repair systems is evaluated. Furthermore, the present prediction is compared with available experimental data to assess the accuracy of the proposed computational model. A micromechanical constitutive model (Liang et al., 2006) based on the concept of the ensemble-volume average for laminated composites is implemented into a finite element program to numerically characterize the compressive response and damage evolution in laminated plates containing a cutout in Chapter 3. The constitutive model incorporates the fiber debonding and microcrack nucleation of laminated composites. Prior to the implementation of the model into the finite element program, the predicted moduli of laminated composites are compared with theoretical bounds and experimental data for the validation and verification of the constitutive model. A series of numerical simulations for a uniaxial test of laminated plate specimens containing a cutout are conducted using the implemented constitutive model. The predictions are compared with experimental data (Lessard...