Study On Flow-induced Vibration Characteristics Of RCC Structure And Damage Identification

The vibration of hydraulic structures caused by flood discharge is a complex phenomena of fluid-structure interaction. Flood discharge structures may occur severe vibration, even distraction, influenced by the complex flood discharge loads. The vibration characteristics of the RCC structure is more complex under the conditions of flood discharge excitation. Launch the research about vibration mechanism and damage identification under the conditions of flood discharge excitation are very important to the design and safe operation of RCC flood discharge structures. The main contents are as follows:Study the property of flow-induced vibration of RCC structure through the methods of hydro elastic model experimental and numerical analysis, combine with the mechanism of flow-induced vibration of flood discharge structure, in this paper. Meanwhile, analyzed the relationship between the flood discharge load, flood discharge structure and flow-induced vibration response. Theoretical analyze and summarize for the strain modal sensitivity of structural damage and strain modal orthogonality, and summarized the existing structure damage identification index based on modal strain.(1)Series model tests of flow-induced vibration have been built, and spectrum analysis, waveform analysis and the time-frequency analysis method are applied to study the vibration testing data. By analyzing the response characteristics of the different structural forms model under the flood discharge excitation to study the overall and stratified flood discharge structures characteristic of stochastic resonance under the conditions of flood discharge excitation.(2)To carry out FEM calculation for flood discharge structures, in different forms, applied different loads. Analysis the vibration response mechanism of structure, and reasonable explanation the flow-induced vibration phenomenon of layered structure appears in the process of flow discharge. Provide the basis for design, construction and operation management of high RCC dam.(3)Using ANSYS to launch numerical simulation analysis on guide wall, and draw three-dimensional distribution about strain modal of the overall and damage structure. Carry out analysis of variation characteristic about strain modal for different types of injury and damage location.(4)Time-history of dynamic strain analysis method is proposed based on strain indicators,which apply to the damage form of cracks and weak belt. According to the skewness coefficient and the mean square error of dynamic strain time-history data could achieve an accurate identification of structural damage; Damage identification method is proposed based on fiber optic sensing and strain indicators.