Point cloud-based automatic finite element modeling utilizing UAV

Historical arch bridges in China have experienced a gradual deterioration in structural integrity due to prolonged use and increasing traffic loads. Ensuring the safety of the arch bridge as well as the pedestrian demands precise health assessment of these bridges, which normally requires finite element (FE) modeling and updating. To facilitate the FE modeling with limited information, a point cloud-based automatic FE modeling strategy is explored in this study. The unmanned aerial vehicle is first employed to do an on-site survey via images and videos to provide the geometric data of the historical arch bridge. They are then transformed into point cloud data to reconstruct a 3D solid model of the bridge. The FE mesh is finally implemented with element properties assigned to obtain the targeted FE model. An ambient vibration test is also conducted to extract the structural modal parameters, for further verification of the constructed FE model and possibly FE model updating. The proposed strategy is based on commonly available software, and thus easy to implement. It offers a rapid means of building the FE model, laying the groundwork for the condition assessment of the historical arch bridges.