间隙式油缸黏滞阻尼器阻尼特性建模与数值仿真分析

Damping characteristic modeling and numerical simulation analysis of the viscous damper of a clearance hydrocylinder

间隙式油缸黏滞阻尼器输出阻尼力较大、安全系数高、结构简单稳定、使用寿命长且制造成本低廉,是一种应用非常广泛的减震耗能装置。针对现实中阻尼器多自由度的需求,同时考虑压差流动和剪切流动的影响,并在活塞出现偏心的情况下,进行了阻尼特性建模。基于阻尼介质流体的本构方程,计算平行平板间隙流体流动的流量。选取合适的微小间隙单元并将其近似看作平行平板间隙流动,通过积分计算流过环形间隙的总流量,分别得到了阻尼器垂直方向和水平方向的阻尼力和阻尼系数表达式。数值仿真分析表明,当间隙较大时,剪切流动对阻尼特性的影响不可忽略,活塞偏心对垂直方向阻尼特性的影响较小,对水平方向阻尼特性的影响较为显著。

The viscous damper of a clearance hydrocylinder is a very extensive application of isolation device,because of its large output damping force,long lifetime,high safe factor,simple structure and low cost.In practice,a damper is multi-freedom degree system.Considering the influence of pressure difference flow and shearing flow,the damping characteristic modeling was done while the piston was eccentric.First,the quantity of fluid flow in the clearance between parallel plates was calculated based on the constitutive equation of damping fluid.Then,appropriate tiny unit was chosen,and it was considered to the fluid flow in the clearance between parallel plates.The total quantity of fluid flow in the circular clearance was calculated by numerical integration and the expressions of damping force and damping coefficients in the vertical and horizontal directions were obtained.Numerical simulation analysis indicated the influence of shearing flow on the damping characteristic was not ignored while the clearance was larger.The influence of eccentricity on the damping characteristic in the vertical direction was small and the influence of eccentricity on the damping characteristic in the horizontal direction was significant.