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| | Abstract | | In Japan, it is necessary to inspect the whole surface of all buildings constructed over 10 years before by the hammering test, but it is not realistic because of the large cost burden of temporary scaffolding etc. On the other hand, the simulated defect embedded under the tile of the outer wall specimen can be detected by the noncontact acoustic inspection method using the acoustic irradiation induced vibration from a small sound source that can be mounted on a sound source mounted UAV (Unmanned aerial vehicle) and a laser Doppler vibrometer. However, large UAVs were unstable at low altitudes (2 m) around the sample due to the wind generated by their own propellers. Therefore, by using a large crane, the outer wall specimen itself was lifted and placed on another specimen (3 m in height) to actually investigate during UAV flight. From the experimental results, it has become clear that although the vibration of the specimen itself due to occasional gusts of wind is detected as noise, basically, defects within the range of directivity of the sound source can be detected. |
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