Simulation And Analysis Of Fluid-structure Interaction Of Formation Process Of Abnormal Structure Noise For Hydraulic Shock Absorber

With the rapid development of related technologies which improved security,stability and maneuverability of vehicle, people put forward higher requirements tovehicle riding comfort, because the vehicle noise reduced riding comfort severely,received wide concern from the academic circles and the business. After years of efforts,other sources of noise on the vehicle has been well controlled, therefore，abnormal noiseof barrel type hydraulic shock absorber gradually became one of the most prominentissues, and has been an important research topic.As a kind of abnormal noise of barrel type hydraulic shock absorber, structureabnormal noise was one of the most prominent and the most complex problem. It’s thefocus of research in the shock absorber abnormal noise. Although a lot of research wascarried out, the research method which based on experimental is lack of research on theflow characteristics inside the shock absorber. Due to the complexity of formationmechanism of the structure abnormal noise, the previous studies on the vibrationsfrequency distribution of structure abnormal noise do not form a consistent conclusion.The above shows that the structure abnormal noise of shock absorber needed morein-depth study.This paper has taken a barrel type hydraulic shock absorber as the object of study.For the process of the air-way impact and the valve adhesion, Simulation and analysiswas carried out separately. The following in-depth study was carried out specifically:①In order to simulate the process of air-way impact in barrel type hydraulic shockabsorber, the fluid-solid interaction model which containing Gas and oil was established.Meanwhile, a normal barrel type hydraulic shock absorber model which without air-waydistance was established too. The simulation calculation was carried out. The axialvibration of piston rod caused by the impact of the fluid flowing through the air-way hasbeen a detailed analysis, and compared with the axial vibration of the normal piston rod.Gas-liquid two-phase flow in Fluid model was analyzed.②The fluid-structure interaction model which simulating Compression strokeswitch to the recovery stroke was established, and the simulation calculation was carriedout. Preload of compensation valve spring and adhesion of the compensation valvecaused the valve to open delay when the shock absorber stroke switch. A detailedanalysis about fluctuations of damping force and axial vibrations of piston rod was given. Fluid flow in Fluid model was analyzed.③According to the fluid-structure interaction model which was Established in thispaper， the numerical theory of solid finite element, fluid finite element andfluid-structure interaction were introduced in this paper. There has a detailed analysisfor the difficult problems which found in simulation process and the treatment methods.Using finite element analysis method to study the noise problem of cylinderhydraulic shock absorber, could observe the internal flow field in shock absorber better,and solve the problem of abnormal noise, at the same time, the finite element methodhas more advantages in shock absorber research and development phase， the researchresults has certain practical significance and certain reference value.