液力减振器空程冲击过程的流固耦合仿真与分析

Fluid-structure interaction simulation and analysis for oil-loss-travel impact of hydraulic shock absorbers

液力减振器内部的振动及冲击是其噪声产生的原因,通过实验和理论分析发现,该振动与冲击主要表现为空程冲击。为揭示液力减振器油液与活塞之间的空程冲击的具体过程和机理,首先通过建立数学模型,计算得到了某一减振器在不同激励下的空程距离;然后采用ADINA软件建立了模拟该减振器空程冲击过程的气-液两相有限元模型,并进行了流固耦合动态仿真;最后分析了活塞杆加速度的时域和频域响应。研究结果显示:流通阀阀片打开瞬间,油液与活塞的空程冲击将使活塞杆产生显著的轴向振动;随着空程距离增大,活塞杆轴向振动越明显。仿真计算结果与减振器噪声实验结果相符,表明该模型理论及其计算方法可解释减振器噪声产生的原因,并为降噪提供参考。

The generation of hydraulic shock absorber noise is the result of its inner vibration and impact.It is clear that the oil-loss-travel impact is the main behavior of its vibration and impact by means of theoretical analysis and tests.In order to reveal the specific process and mechanism for the oil-loss-travel impact between oil fluid and piston of a hydraulic shock absorber,firstly the oil-loss-travel distance under different excitations for a certain shock absorber was calculated through building its mathematical model.And then,the two-phase gas-oil finite element model for simulating the oil-loss-travel impact of the hydraulic shock absorber was established with ADINA and its fluid-structure interaction dynamic simulation was conducted.The responses of its piston rod in time domain and frequency domain were analyzed. The results showed that the significant axial vibration of the piston-rod is caused by the oil-loss-travel impact between oil fluid and piston at the moment for opening of circulating valve;with increase in oil-loss-travel distance,the axial vibration of the piston rod grows.The simulation results agreed well with those of the hydraulic shock absorber noise tests,it was shown that the model theory and its calculation method can explain the cause of the hydraulic shock absorber noise,and provide a reference for noise reduction.