The Theory Research Of Footbridge TMD Semi-active Control

By leaps and bounds situation of our transportation development,various footbridge construction have developed rapidly, with the new footbridge structure forms (e.g. batter footbridge, suspension cable footbridge) and new materials (such as high-strength steel, fiber reinforced plastics (FRP) )are Applied in footbridge, footbridge is to the big stride, light quality direction, many domestic cities built the footbridge span from the about 20m in the past to 50 ~ 60m now,To the large span and gently the footbridge, quality change will bring footbridge vibration frequency changing, which eventually led to the resonance of the footbridge in different frequencies under different quality role.The object of this paper study is the footbridge whose inherent frequency is changing in using process, and realized to such footbridge TMD semi-active control in the vertical vibration.The main contents of the research are as follows:1. Collected and analyzed the data of the test footbridge model. Introduce the data collection equipments, test model and collection process, this paper expounded physical significance of FFT transform in the signal analysis process. Analyzed the changing conditions of inherent frequency of the footbridge model on the cases of changing number of people.2. Considered the tune mass dampers passive control as the premise, and got the following two cases of optimal control parameters, one case is considering the main structure frequency unchanged, and the other case is considering the main structure frequency changed. And comparative analysis passive control effect with the two control parameters in two cases. Theoretically got optimal parameters of passive TMD control which are suitable for main structure changing in frequency.3. Analyzed the vibration characteristics of footbridge in frequency domain which was taken the TMD semi-active control. And discussed the various parameters on TMD control effect of influence, and in passive co- ntrol of comparative analysis; Analyzed the footbridge vibration by Wils- on–θ, and got the displacement, velocity and acceleration of the time- history of vibration characteristics of the footbridge by semi-active con- trol . Through the two aspects of theory simulation analysis in time dom- ain and frequency domain, verified the TMD changed quality semi-active control is effective and feasible.4. Put forward the theory of the simple TMD semi-active control devi- ces in this article, and described the role of each part and parameter dete- rmination method, Theoretically simulated and analyzed the footbridge TMD semi-active control and the implementation method, and Detailed descript the selection and decorate of the Control quality block and signal TMD. Deployed and prospected for the future work, and laid a theoretic -al foundation for further research.