空气阻尼对网孔式弹性垫板动力学特性的影响研究

Effect of air damping on the dynamic characteristics of a mesh type elastic backing plate

轨道交通列车走行基础采用了大量弹性垫板用于降低振动的影响。为了提高弹性垫板的阻尼,消耗更多的振动能量,提出一种空气阻尼网孔式弹性垫板。该垫板利用不同材料的弹性差异,在其弹性单元的空腔中形成主气室和附气室,两气室之间用节流孔联通。在列车动荷载作用下,两气室中的气体在节流孔中往复流动产生阻尼作用。研究表明,节流孔孔径和气室体积比是影响弹性垫板动力学性能的关键参数,减小节流孔孔径和气室体积比可以降低弹性垫板的刚度并增大其阻尼。空气阻尼网孔式弹性垫板的刚度和阻尼可以通过改变节流孔孔径和气室体积比灵活调整,其性能优于普通网孔式弹性垫板和填充高阻尼材料的网孔式弹性垫板。该垫板采用空气阻尼替代网孔中填充的阻尼材料,可以节省大量的生产成本。

A large number of elastic pads are used to reduce the impact of vibration in the foundation of rail transit trains.In order to improve the damping performance of the elastic pad and consume more vibration energy,an air damping mesh type elastic pad was proposed.The backing plate uses the difference in elasticity of different materials to form a main air chamber and an auxiliary air chamber in the cavity of its elastic unit,and the two air chambers are communicated with a throttle hole.Under the action of the train’s dynamic load,the gas in the two gas chambers reciprocately flows through the orifice to produce a damping effect.The studies show that the aperture of the orifice and the volume ratio of the air chambers are the key parameters that affect the dynamic performance of the elastic pad.Reducing the aperture of the orifice and the volume ratio of the air chambers can reduce the stiffness of the elastic pad and increase its damping.The stiffness and damping of the air damping mesh type elastic pad can be flexibly adjusted by changing the throttle hole diameter and the air chamber volume ratio,and its performance is better than ordinary mesh elastic pads and mesh elastic pads filled with high damping material.The backing plate using air damping to replace the damping material filled in the mesh can save a lot of production cost.