变摩擦TMD特性和简谐激励控制效果的研究

Variable friction TMD and its control effectiveness under harmonic excitation

提出一种变正压力式变摩擦装置,通过改变摩擦面正压力实现摩擦力随系统位移增大而增大。将其用于TMD能有效克服常摩擦TMD摩擦力不可变的缺点。采用一阶谐波平衡法推导了变摩擦系统的等效阻尼比和等效频率,分析了系统各参数对其等效阻尼比和等效频率的影响,通过与经典阻尼单自由度系统的比较探讨了单自由度变摩擦系统的频率响应特性。从理论和试验两个方面研究了简谐激励下变摩擦TMD对单自由度主结构振动控制的特点。分析结果表明,变摩擦TMD的频率响应特性与经典阻尼TMD类似,二者都能有效减小主结构频率响应曲线的峰值,试验结果验证了变摩擦TMD在简谐激励下的有效性。

A variable friction system with normal pressure changeable was presented,where the frictional force of the system can be increased with the increase of displacement of the system.The new system can be used in TMD to avoid the disadvantage of invariable friction TMD.Using first order harmonic balance method,the equivalent damping ratio and frequency of SDOF variable friction system were deduced and analyzed.The frequency response characteristics of SDOF variable friction system were discussed by comparing with SDOF classical damping system.The control effectiveness of variable friction TMD under harmonic excitation was inspected theoretically and experimentally.The results demonstrates that the frequency response characteristics of variable friction TMD and classically damping TMD are similar and both can effectively reduce structural response under harmonic excitation.