structuralhealth monitoring of large concrete structures · structuralhealth monitoring of large...
TRANSCRIPT
![Page 1: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/1.jpg)
Structural Health Monitoringof Large Concrete Structures
Patrik FröjdEngineering Geology, Lund University
1
![Page 2: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/2.jpg)
Non‐Destructive Testing (NDT)
2
![Page 3: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/3.jpg)
Structural Health Monitoring (SHM)
3
![Page 4: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/4.jpg)
Ultrasonic waves
• Velocity• Attenuation• Nonlinearity
4
![Page 5: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/5.jpg)
Coda waves
5
![Page 6: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/6.jpg)
Continuous waves
6
![Page 7: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/7.jpg)
Continuous waves ‐ Lock‐In amplifier
7
Signal Recovery 7210 Multi‐channel lock‐in
• ”Locks in” on a referencesignal
• Measures amplitude and phase relative to reference signal
• Samples signals withextremely low SNR
![Page 8: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/8.jpg)
Pulsed vs Continuous waves
8
![Page 9: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/9.jpg)
Pulsed vs Continuous waves
9
[40 dB = 100x]
dB
dB dB dB
dB dB
dB
![Page 10: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/10.jpg)
Transducer network
10
![Page 11: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/11.jpg)
Transducer network
11
![Page 12: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/12.jpg)
Transducer network
12
![Page 13: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/13.jpg)
Transducer network
13Deviation from baseline (std)
![Page 14: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/14.jpg)
Transducer network
14
Deviation from baseline (std)
Deviation from baseline (std)
![Page 15: StructuralHealth Monitoring of Large Concrete Structures · StructuralHealth Monitoring of Large Concrete Structures Patrik Fröjd EngineeringGeology, Lund University 1](https://reader034.vdocument.in/reader034/viewer/2022042911/5f41edb721d95962e24cc8a0/html5/thumbnails/15.jpg)
Conclusions
• Diffuse wave fields suitable for SHM of concrete.• Continuous wave transmission potential for greater distances or higher frequencies at given distance.
• ”Small” damage (~cm) detected over ”long” distance (>8 m).• 50 kHz waves can be used for localization through tomography .
15