Mechanical analysis of a cracked beam reinforced with an external FRP plate

Fracture Resistance of a Cracked Concrete Beam Post-strengthened with FRP Sheets

“…However, the loading capacity has been controlled by the concrete strength. Figure 9 shows the loading capacity of Case 2, based on the analysis of Wu and Davies (2003), with different f c when l p /l = 0.01. It is seen that the loading capacity drops at the beginning of crack propagation and increases with f c .…”

“…Assuming that plane sections remain plane after deformation, a linear distribution of strain over the beam depth is obtained ( Figure 3b). Combining this strain distribution and the constitutive relations for both concrete and FRP sheets, the stress distributions on the cross-section at the midspan of the beam can be shown in Figure 3c (Wu and Davies, 2003). The resultant tensile force on the cross-section consists of contributions from three parts: the tensile stress in concrete following the linear elastic law given by σ = Eε from 0 to f t , the stress distribution in the vicinity of the crack tip, i.e., the fracture process zone, and the tensile force due to extension of the FRP sheets.…”

“…Should the compressive behavior of the concrete be known, the resultant compressive force could be integrated over the compressive area and the position of the neutral axis of the beam would be determined using equilibrium. For a parabolic variation of the compressive curve proposed by Hognestad et al (1955), with f c and ε c defining the maximum compressive stress and strain, this equilibrium equation is given by (Wu and Davies, 2003) A…”

“…The unidirectional FRP sheets are placed near the bottom surface of the tensile zone ( Figure 1) of the cracked beam. The loading capacity of such an FRP reinforced concrete structure has been investigated in a previous paper (Wu and Davies, 2003), in which some of the formulations and results are referenced in the current analysis. The research is based on the consideration of the constitutive relations and deformation properties of the individual constituents of plain concrete and FRP sheet.…”

Advances of Finite Element Analysis for FRP Concrete Beams

“…A fictitious crack approach was adopted by Wu and Davies (2003) to estimate the equivalent bridge effect of the fracture process zone of concrete for a beam subjected to three-point bending and externally reinforced with unidirectional FRP plate near the bottom surface of the tensile zone. The rebar/concrete interface debonding of FRP-strengthened concrete beams with perfect bonding assumption between the concrete and FRP plate under fatigue load was investigated by Zhang and Shi (2008).…”