2017 Fiscal Year Research-status Report
Practicability study on drive-by methods for vibration-based bridge damage detection and modal identification
| Project/Area Number |
17K14716
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| Research Institution | Kyoto University |
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Principal Investigator |
張 凱淳 京都大学, 工学研究科, 講師 (50751723)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Keywords | bridge inspection / damage detection / drive-by inspection / moving vehicle / VBI |
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| Outline of Annual Research Achievements |
This study aims to present the practicability of drive-by methods for vibration-based bridge damage detection and modal identification by developing a practical drive-by vibration sensing system. The research achievements in the first year can be summarized as follows.
1. An appropriate laboratory-scale vehicle model were proposed for drive-by bridge inspections and tested on a scaled bridge model
A tractor-trailer system was proposed, with the tractor having the heaviest weight and the trailer having the highest bouncing frequency. The heavy tractor was to excite the bridge easily. The trailer of high frequency was shown to transmit bridge’s vibration energy better, and therefore made the bridge dynamic properties more identifiable. The performance of this tractor-trailer system to identify bridge dynamic properties was verified in the laboratory-scale moving vehicle tests. In slower speed cases, the bridge-related frequencies were obviously identified from the trailer’s PSD, but in higher speed cases, more noisy peaks irrelevant to bridge frequencies presented due to the negative effect of roadway profiles.
2. The feasibility of the drive-by damage detection method was demonstrated. The damage of the bridge was detected by the change in the spectral distribution pattern of the trailers’ acceleration responses. Also, the degree of the pattern change was consistent to the degree of damage.
The above achievements were published in several international journals and presented in several national and international conferences.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
In my proposal, I proposed to conduct the following studies in the first year.
A. Presenting an optimal sensing system (hardware). Its vehicle structure has optimal dynamic properties and criteria, and its sensing modulus and devices are well laid out.
B. Designing, manufacturing, and assembling laboratory-scale sensing system models.
They were conducted smoothly; an optimal sensing system was proposed, assembled, and tested on a laboratory-scale bridge model.
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| Strategy for Future Research Activity |
From the second year, the following issues would be comprehensive studied.
1. Developing and Validating Incorporated Analysis Methods (software)
We have developed several analysis methods for identifying bridge modal properties and detecting potential damage from the moving vehicles’ vibrations. Those analysis methods will be incorporated into the laboratory-scale sensing system and validated with our scaled bridge. Foreseeable challenges are the too large roadway roughness-induced vibrations and the too small bridge-induced vibrations. Its solutions or improvements will be proposed in both hardware and software ways and tested repeatedly in laboratory. Moreover, those repeating laboratory tests would help us discover other problems and challenges that hardly stand out in numerical simulations.
2. Proposing the Blueprint of a Full-scale Sensing System and Testing It in Field
Blueprints of a full-scale sensing system will be proposed as per the feedback from the laboratory experiments. An intuitive idea is to take a commercially available vehicle as the trailer and to make a trailer that serve as the sensing platform equipped with sensors. The trailer is therefore a key element, which should satisfy the above principles and criteria. The scale effects will be carefully considered between laboratory- and full-scale systems. Such a full-scale drive-by sensing system will be assembled and tested on several field bridges.
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| Causes of Carryover |
Reasons: we used less budget in purchasing equipment and assembling the laboratory-scale test vehicle model.
Usage plan: purchasing consumables, like batteries, tapes, etc.
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