Research On Dynamic Model And Pulation Absorption Effect Of Bionic Hydraulic Pipeline

High speed and high pressure is one of the main developing trends of hydraulic transmission system?High speed and high pressure can improve hydraulic system power to weight ratio,but also cause vibration of hydraulic system to be more complex.The pipeline resonance instability will cause serious accidents in some special working condition,and the noise pollution caused by high-frequency vibration seriously affects the physical and mental health of workers.Axial piston pump is an important component of the hydraulic system.The flow pulsation and mechanical vibration generated by the axial piston pump are mostly transmitted through the hydraulic pipeline to the system.Therefore,absorbing the flow pulsation of the pump port and restraining vibration has become one of the important directions in the research of vibration control for hydraulic pipelines in recent years.In this paper,the biological mechanism of "the left ventricular outlet vessel of the cheetah heart can tolerate high pressure and high frequency blood pulsation" is used to create a bionic hydraulic pipeline with three layers of structure,which provides an innovative idea for the control of the vibration of the pipe of the hydraulic pump.The main research work is as follows:(1)A bionic hydraulic pipeline structure is designed.Considering the influence of the nonlinear characteristics of silica gel material,the traditional hydraulic fluid solid coupling dynamic model 14-equation is combined with the constitutive model of silica gel material to establish a bionic hydraulic pipeline fluid solid coupling dynamic model filled with hydraulic oil.(2)The fluid solid coupling dynamic model of the bionic hydraulic pipeline is transformed into a frequency domain model by Laplace frequency domain transform,and the transfer matrix is obtained in the frequency domain.The transfer matrix is solved by MATLAB software programming with the nonlinear boundary conditions of silica gel material and fluid solid coupling,and the analytical solution of the bionic hydraulic pipeline is obtained.In order to verify the results of the solution,a test model of a bionic hydraulic pipeline is made,and the modal analysis of the hammer test is carried out.The response curve of the frequency domain is obtained.The results are compared with the results of the MATLAB solution to verify the correctness and accuracy of the above dynamic model and the solution method.(3)The two-way fluid solid coupling simulation analysis of bionic hydraulic pipeline is carried out by using ANSYS Workbench software.The absorption effect of a bionic hydraulic pipeline on the flow pulsation of the oil and the vibration of the pipeline under the conditions of different pipeline length,silica gel layer thickness and oil pressure are studied respectively,and compared with the simulation results of ordinary stainless steel pipeline.(4)Trial production of bionic hydraulic pipeline test piece with different length and thickness of silica gel layer,The effect of bionic hydraulic pipeline on pulsating absorption is studied.By detecting the pressure pulsation of the import and export of the bionic hydraulic pipeline and the vibration signal of the pipeline,the absorption effect of the bionic hydraulic pipeline on the flow pulsation of the pump and the vibration of the pipe is analyzed and compared with that of the ordinary stainless steel hydraulic pipe.