Figure 1.
FE model of seven-strand anchorage system for stress analysis. (a) Multi-strand anchorage system and (b) discretization and boundary condition.
Figure 1.
FE model of seven-strand anchorage system for stress analysis. (a) Multi-strand anchorage system and (b) discretization and boundary condition.
Figure 2.
Variation of stress fields due to strand breakage. (a) Circumferential stress (σθ), (b) radial stress (σr), and (c) axial stress (σz).
Figure 2.
Variation of stress fields due to strand breakage. (a) Circumferential stress (σθ), (b) radial stress (σr), and (c) axial stress (σz).
Figure 3.
Circumferential stress variation (MPa) at relative heights of the anchor head. (a) Near-bottom (a/H = 0.15), (b) middle (a/H = 0.5), and (c) near-top (a/H = 0.9).
Figure 3.
Circumferential stress variation (MPa) at relative heights of the anchor head. (a) Near-bottom (a/H = 0.15), (b) middle (a/H = 0.5), and (c) near-top (a/H = 0.9).
Figure 4.
2-DOF impedance model.
Figure 4.
2-DOF impedance model.
Figure 5.
PZT interface technique for stress monitoring. (a) PZT interface mounted on a host structure and (b) shifts in EM impedance signature due to stress change.
Figure 5.
PZT interface technique for stress monitoring. (a) PZT interface mounted on a host structure and (b) shifts in EM impedance signature due to stress change.
Figure 6.
Design of a hoop-type PZTs interface for multi-strand anchorage system. (a) Hoop-type PZT interface on a multi-strand anchorage system, (b) multi-PZTs interface, and (c) segmental PZT interface.
Figure 6.
Design of a hoop-type PZTs interface for multi-strand anchorage system. (a) Hoop-type PZT interface on a multi-strand anchorage system, (b) multi-PZTs interface, and (c) segmental PZT interface.
Figure 7.
FE Model of a segmental PZT interface.
Figure 7.
FE Model of a segmental PZT interface.
Figure 8.
Impedance response of the PZT interface.
Figure 8.
Impedance response of the PZT interface.
Figure 9.
Eigen-modes of hoop-type PZT interface.
Figure 9.
Eigen-modes of hoop-type PZT interface.
Figure 10.
FE model of multi-strands anchorage embedded with hoop-type PZT interface.
Figure 10.
FE model of multi-strands anchorage embedded with hoop-type PZT interface.
Figure 11.
Impedance response of PZT 1 interface under strand breakage events.
Figure 11.
Impedance response of PZT 1 interface under strand breakage events.
Figure 12.
Impedance responses under strand breakage events. (a) PZT 1, (b) PZT 2, (c) PZT 3, (d) PZT 4, (e) PZT 5, and (f) PZT 6.
Figure 12.
Impedance responses under strand breakage events. (a) PZT 1, (b) PZT 2, (c) PZT 3, (d) PZT 4, (e) PZT 5, and (f) PZT 6.
Figure 13.
RMSD indices of PZT sensors’ impedance signature for locally damaged strand. (a) Peak 1’s impedance and (b) Peak 2’s impedance.
Figure 13.
RMSD indices of PZT sensors’ impedance signature for locally damaged strand. (a) Peak 1’s impedance and (b) Peak 2’s impedance.
Figure 14.
Linear tomography of RMSD indices (%) using all PZTs 1–6: Strand 1 breakage. (a) Peak 1’s impedance and (b) Peak 2’s impedance.
Figure 14.
Linear tomography of RMSD indices (%) using all PZTs 1–6: Strand 1 breakage. (a) Peak 1’s impedance and (b) Peak 2’s impedance.
Figure 15.
Linear tomography of RMSD indices (%) using all PZTs 1–6: Strand 7 breakage. (a) Peak 1’s impedance and (b) Peak 2’s impedance.
Figure 15.
Linear tomography of RMSD indices (%) using all PZTs 1–6: Strand 7 breakage. (a) Peak 1’s impedance and (b) Peak 2’s impedance.
Figure 16.
Linear tomography of RMSD indices (%) using all PZTs 1–6: Strands 1 and 7 breakage. (a) Peak 1’s impedance and (b) Peak 2’s impedance.
Figure 16.
Linear tomography of RMSD indices (%) using all PZTs 1–6: Strands 1 and 7 breakage. (a) Peak 1’s impedance and (b) Peak 2’s impedance.
Figure 17.
Linear tomography of RMSD indices (%) using PZTs 1, 3 and 5: Peak 1’s impedance. (a) Strand 1 breakage, (b) Strand 7 breakage, and (c) Strands 1 and 7 breakage.
Figure 17.
Linear tomography of RMSD indices (%) using PZTs 1, 3 and 5: Peak 1’s impedance. (a) Strand 1 breakage, (b) Strand 7 breakage, and (c) Strands 1 and 7 breakage.
Figure 18.
Linear tomography of RMSD indices (%) using PZTs 2, 4 and 6: Peak 1’s impedance. (a) Strand 1 breakage, (b) Strand 7 breakage, and (c) Strands 1 and 7 breakage.
Figure 18.
Linear tomography of RMSD indices (%) using PZTs 2, 4 and 6: Peak 1’s impedance. (a) Strand 1 breakage, (b) Strand 7 breakage, and (c) Strands 1 and 7 breakage.
Figure 19.
Experimental set-up of the multi-strand anchorage system. (a) Overview of the test setup (unit: m), (b) prestressed multi-strand anchorage system, and (c) hoop PZT interface mounted on the anchor head.
Figure 19.
Experimental set-up of the multi-strand anchorage system. (a) Overview of the test setup (unit: m), (b) prestressed multi-strand anchorage system, and (c) hoop PZT interface mounted on the anchor head.
Figure 20.
Impedance responses of the hoop PZT interface under prestressing cases. (a) Prestressing cases of Strand 9: PS1–PS4 and (b) prestressing cases of Strand 1: PS4–PS7.
Figure 20.
Impedance responses of the hoop PZT interface under prestressing cases. (a) Prestressing cases of Strand 9: PS1–PS4 and (b) prestressing cases of Strand 1: PS4–PS7.
Figure 21.
RMSD quantification of impedance responses under prestressing cases. (a) Prestressing cases of Strand 9: PS1–PS4 and (b) prestressing cases of Strand 1: PS4–PS7.
Figure 21.
RMSD quantification of impedance responses under prestressing cases. (a) Prestressing cases of Strand 9: PS1–PS4 and (b) prestressing cases of Strand 1: PS4–PS7.
Table 1.
Material properties of anchorage components.
Table 1.
Material properties of anchorage components.
Parameters | Anchor Head, Bearing Plate, and Wedges |
---|
Young’s modulus, E (GPa) | 200 |
Poisson’s ratio, υ | 0.3 |
Mass density, ρ (kg/m3) | 7850 |
Table 2.
Material properties of FRP sheet.
Table 2.
Material properties of FRP sheet.
Young’s Modulus E, (GPa) | Poisson’s Ratio ν | Mass Density ρ (kg/m3) | Damping Loss Factor η |
---|
145 | 0.30 | 1700 | 0.02 |
Table 3.
Material properties of PZT 5A.
Table 3.
Material properties of PZT 5A.
Young’s Modulus E, (GPa) | Mass Density ρ (kg/m3) | Damping Loss Factor η | Dielectric Constant, εT33 (Farad/m) | Dielectric Loss Factor δ | Coupling Constant d31 (m/V) |
---|
62.1 | 7750 | 0.0125 | 1.53 × 10-8 | 0.015 | −1.71 × 10−10 |
Table 4.
Simulation cases of strand breakage in the FE model.
Table 4.
Simulation cases of strand breakage in the FE model.
Case | Simulation Scenario |
---|
Intact | All wedges (Strands 1–7) were assigned by 150 kN |
Case 1 | Strand 1 was broken |
Case 2 | Strand 7 was broken |
Case 3 | Strands 1 and 7 were both broken |
Table 5.
Combination of PZT sensors for linear tomography of RMSD index.
Table 5.
Combination of PZT sensors for linear tomography of RMSD index.
Combination | PZT 1 | PZT 2 | PZT 3 | PZT 4 | PZT 5 | PZT 6 |
---|
1 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
2 | ✓ | | ✓ | | | ✓ |
3 | | ✓ | | ✓ | | ✓ |
Table 6.
Prestressing cases of the lab-scale multi-strand anchorage system.
Table 6.
Prestressing cases of the lab-scale multi-strand anchorage system.
Case | Applied Prestress Force (kN) |
---|
Strand 9 | Strand 1 |
---|
PS 1 | 0 | 0 |
PS 2 | 49.1 | 0 |
PS 3 | 98.1 | 0 |
PS 4 | 147.2 | 0 |
PS 5 | 147.2 | 49.1 |
PS 6 | 147.2 | 98.1 |
PS 7 | 147.2 | 147.2 |