Concrete arch dam modal shape identification method based on unmanned aerial vehicle video shooting

Abstract

The invention discloses a concrete arch dam modal shape recognition method based on unmanned aerial vehicle video shooting. The method comprises the steps of arranging mark points at the dam crest; obtaining a dam crest image through a pan-tilt camera on the unmanned aerial vehicle, and obtaining a dam crest vibration video; according to the first four-order natural frequency of the arch dam, obtaining a video after the first four-order motion of the original dam vibration video is amplified; and selecting a frame with the maximum dam crest deformation in the original four-order motion amplification video of the dam, identifying the centroid coordinates of each mark point in the image, obtaining the centroid coordinate change of each mark point before and after vibration, and normalizing the maximum value of the relative coordinate change of each mark point to obtain the four-order modal shape of the dam crest of the arch dam. Through a non-contact method, approximate full-field measurement of the arch dam crest vibration mode can be realized, the spatial resolution is high, and support can be provided for subsequent dam model updating and damage identification.

Description

technical field [0001] The invention belongs to the technical field of dynamic characteristic analysis, finite element model update and damage identification of concrete arch dams, and in particular relates to a concrete arch dam modal mode shape identification method based on unmanned aerial vehicle video shooting. Background technique [0002] As an important dam type in water conservancy and hydropower projects, arch dams have made great contributions to national economic and social development. However, during their service period, due to extreme environmental loads (such as earthquakes, floods, etc.), construction defects, poor management and maintenance, and aging after long-term use, many dams have various diseases and hidden dangers, which may lead to structural instability. Or strength damage, seriously affecting the normal operation and benefit of the project. Therefore, regular or real-time health monitoring of arch dams is of great significance to ensure its saf...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the defects of the above-mentioned background technology, the present invention provides a concrete arch dam modal shape recognition method based on UAV video shooting, aiming at the time-consuming and labor-intensive sensor installation and space-resolving problems existing in the contact dynamic test process of the existing dam structure. In order to solve the problems of low efficiency, it is proposed to realize the vibration measurement of the dam body approximately in the whole field through the non-contact camera measurement technology. This technology does not need to install additional sensors, which is more convenient and efficient, and has higher spatial resolution.

Images