Analysis of bridge pier's dynamic characteristics considering fluid-solid interface coupling

In the study of bridge pier's dynamic characteristics, the modal analysis is the foundation of other dynamic analysis and is of great significance for studying other dynamic performance. Based on the dynamic theory of fluid-solid interface coupling, a 3D water-structure coupling finite element modal is established and computed by ANSYS. To verify the validity of the calculation results, the results of finite element software is compared with the analytical solutions in reference books. The analysis indicated that the results of finite element software are reasonable when the radius of bridge pier is five times the radius of water body. The ratio of water depth and the bridge pier's height has a great influence on the change scale of bridge pier's frequency. With the increase of bridge pier's height-diameter ratio, the first three order natural vibration frequency is reduced.