Related Matters-> : 
| Structural integrity can be quantified with acoustic emission activity
induced by live traffic loads
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Damage Evaluation System with AE technique Using Mobile loads
- DeSAMO - |
| Key words: acoustic emission (AE), Structural integrity, damage quantification, railway/concrete
structures, mobile loads (traffic loads), secondary AE |
Note: DeSAMO for concrete structures was developed by a joint research program with Railway Technical Research Institute, whereas DeSAMO for brick structure was made, resulted from the collaboration study with East Japan Railway Company. Their kind permission to present the system in this site is greatly appreciated
Measurement procedure: AE sensors are placed onto the surface of structures;
in case of damaged, AE activity (secondary AE activity) from the defects,
induced by mobile loads, would be detected; and finally in order to extract
the AE signals only from the damage-related areas, specially developed
filtering is performed. Consequently damage-related information as the
damage areas and damage degree can be provided to the administrator.
>Train induced secondary AE activity
>Primary AEs are generated due to crack growth/formation, while the
secondary AEs are from existing cracks.
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>Jam packed train used for inducing AE activity
>Typical AE activity due to damage progress with incremental cyclic loads |
Movie of in-situ AE monitoring
(mpg，3MB) |
>In-situ AE monitoring for plain concrete pier
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Key features:
- In AE monitoring, it is an indispensable condition to apply external loads or internal stress variation. This requirement is achieved by live loads with transportation, i.e., no special loads are needed while diagnosing the structures.
- Using tailored AE sensors and software package, broad range monitoring
is possible i.e., not only for internal area in which sensors are surrounded,
but for out side of the surrounded area both can be reasonably diagnosed
with the system.
- When additional measurements like structural behavior can be recorded incorporated
with AE monitoring, newly developed damage indices as RTRI or Calm ratio can be obtained. Then
damage can be quantified reasonably with the indices.
- Aging can be estimated with routine AE inspection. Additionally, reinforcement effect or repair effectiveness can also be evaluated through the AE testing.
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>3D AE sources
>Damage indices obtained through monitoring
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Applications
Basically, the DeSAMO can be applied for the structures where load/stress
variation can be expected under in-service. As for typical in-service loads,
there are traffic loads, wind energy, temperature stress, and so forth.
- Railway structures (super structures, sub-structure) -railway traffic-
- Road structures (Super structures, substructures) -automobiles-
- Chimneys and foundations of wind energy. -wind energy-
- Concrete structures -temperature variation due to sun light-
- Mass concrete structures -water pressure, earth pressure-
Past applications
- Railway structures (concrete piers), Tokyo Met.
- Railway structures (concrete piers), Chiba Pref.
- Railway structures after repaired (concrete piers), Chiba Pref.
- Railway structures RC piers for rapid train, Iwate Pref.
- Railway structures (concrete piers), Kanagawa Pref.
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