TVMD的减振机理及其提升连续梁减震性能的研究

Control mechanism of TVMD and its performance improvement for seismic mitigation of continuous bridge

TVMD(Tuned Viscous Mass Damper)是一种能将实际质量放大上千倍,且能利用惯性力和调谐效应的新型减振装置。为有效提升连续梁桥的减震效果,研究采用空间分布的TVMD实现连续梁减震的优化设计和高效性能。先以TVMD对单自由度结构减震为例,探究TVMD在调谐频率处的高阻尼效应,及其附加刚度对结构动力特征的影响机制,揭示针对多个TVMD开展同步设计的必要性;进而建立连续梁桥多自由度精细模型,采用基于H2性能的梯度优化法实现多个TVMD的参数优化;分别基于连续梁桥纵、横向减震时的典型状态,实现空间分布且可能对多阶模态调谐的TVMD的优化设计,就连续梁桥的稳态谐振响应以及不同谱特性的地震波输入时的地震响应开展减震分析,阐明了TVMD相对于VD(Viscous Damper)减震时的高效性能。

Tuned viscous mass damper(TVMD)is a new type of control equipment that can produce apparent mass being thousands times of its original mass level,and can utilize the inertial force and tuning effect.To effectively improve the performance for the seismic control of continuous bridge under seismic excitation,the distributed TVMDs are studied to realize their optimal design and remarkable performance.The seismic control of structure with single degree of freedom by using a TVMD is taken as an example firstly.The significant damping effect provided by the TVMD at the resonance frequency of the structure is investigated.The mechanism that additional stiffness provided by the TVMD affects the structural dynamical characteristic is demonstrated,which reveals the necessary to synchronous design the multiple TVMDs as a whole.A fine finite element model of the continuous bridge is built,and the parameters of the multiple TVMDs are optimized by using the gradient-based optimization method based on H 2 performance criterion.Based on the typical states of the continuous bridge for mitigating the longitudinal and transversal seismic responses,the multiple TVMDs that distributed at multiple positions and maybe tuned to multiple modes are optimally designed.The steady-state harmonic responses and the seismic responses under the input excitations with different spectra characteristics are analyzed for the vibration control of the continuous bridge,by which the high effectiveness of the TVMDs comparing with the VDs is validated.