Control And Its Optimization Of The Bridge Induced And Wind Induced Vibration Of Self-Stayed Crooked Rod On Bridge

The structures for fixing the lamps or traffic monitors are called by a joint name of self-stayed crooked rod on bridges. Wind and the bridge vibration will induce the vibration of the self-stayed crooked rod on bridge and these kinds of vibration will cause fatigue of structures and reduce the longevity of the lamps, traffic monitors and their accessories. Therefore, it makes sense to study the wind-induced and bridge-induced vibration control of the self-stayed crooked rod on bridge.Firstly, the 3D-dynamic finite element model of the self-stayed crooked rod on bridge was established in ANSYS using the shell element and the 2D-lumped mass model is also derived from the 3D model by the method of free-degree reduction in order that the major dynamic characteristics of the crooked rod may be remained. The dynamic characteristics obtained from the 2D-model are consistent with those from the 3D-model. So the 2D-lumped mass model can be used for the vibration control analysis of the crooked rod.Secondly, numerical simulation method was employed to study the distribution of mean wind pressure on the self-stayed crooked rod on bridge. Based on the N-S equations and k-ε turbulence model, the CFD simulation results of mean wind pressure, wind pressure coefficients and the shape factors of the crooked rod under various wind directions were obtained and compared with the data of the Load Code. Then based on the harmonic-wave superposition method, the fluctuation wind velocity was simulated and the fluctuating pressure on the crooked rod was obtained on the basis of quasi-steady theory.Then the wind induced vibration was analyzed in the time and frequency domain with the wind load obtained. The passive energy dissipation devices - tuned mass damper was used in structure wind induced vibration control study and the parametric optimization of the damper was discussed. The equivalent damp curves to the various parameters of TMD were obtained. Vibration control analysis in the time and frequency domain shows that the wind-induced response of the crooked rod is effectively decreased according to the optimization curve derived in thispaper.At last, the bridge-induced vibration and the bridge-induced vibration control of the crooked rod was studied because the bridge vibration can also induce the vibration of the crooked rod. According to transfer function theory in frequency-domain analysis, the response of the self-stayed crooked rod vibration under white noise base excitation was calculated. The use of samdwich rubber cushion in vibration control was studied to mitigate the bridge induced response, especially the influence of the performance parameter of the cushion on the efficiency of the vibration control. The comparison of the vibration response of the rod structure before and after the vibration isolation shows that the rubber cushion can effectively mitigate the bridge-induced vibration of self-stayed crooked rod on bridge.