This
research studies FRP debonding from concrete substrate of Modified Double
Cantilever Beam (MDCB) specimen
undergoing global mixed mode I/II loading. A
series of 2D finite element models were built using ANSYS 10.0 software package
to simulate the MDCB test. A modified virtual crack closure technique (VCCT)
was used to extract the mode I and mode II
interfacial energy release rates
from the models. The finite element model was validated and calibrated by
experimental data. The relationship between loading angle and critical
interfacial energy release rate was obtained by a series of FEM analysis with
different loading angles. Parametric studies were conducted to investigate the
characteristics of FRP bonded concrete system. Seven parameters were
considered: Young’s modulus of concrete strength, Young’s modulus and
thickness of primer concrete layer, Young’s modulus and thickness of adhesive layer and
Young’s modulus and thickness of FRP. It was found that Young’s moduli of the
materials had relatively small effects, while the thicknesses of primer
concrete, adhesive layer and FRP had significant effects on the interfacial
energy release rate while FRP debonding failure happened.