Study On The Influence Of Typical Soil Topography On Vehicle Vibration

Harmful vibration will increase the gap between vehicle parts,reduce the service life,long-term exposure to harmful vibration will also cause damage to the driver and passenger's body,so vehicle vibration has been a hot topic of research at home and abroad.The generation of vibration is related to the excitation source.During the driving process of the vehicle,the excitation sources are mainly divided into the engine transmission excitation and the excitation generated by road roughness input.The original roughness of hard pavement can be used as an effective incentive source,while the soil soft pavement has the characteristic of easy deformation,so the original roughness cannot be treated directly as an incentive source.In order to explore the relationship between the incentive force of soil soft pavement roughness and vehicle vibration,the rectangular pit road was used to simulate the gully road in the field to conduct vehicle vibration test,which mainly includes the following aspects.1.Two types of rectangular pit pavement were constructed in the soil trough laboratory.The first type is a rectangular pit with fixed spacing between two pits and variable depth and span,which is divided into 21 groups of tests.The second type is fixed rectangular pit size,with the spacing between rectangular pits as a variable,a total of 8 groups of tests.The acceleration sensor is fixed to the position of the axle of the frame,and the driving force drives the test bench for vibration test.2.Matlab software was used to write programs that analyze the power spectral density and average power of the collected data.It is used to explore the distribution range of the vibration frequency peak in the Z-axis direction and the X-axis direction as the depth and span of the rectangular pit change,as well as the vibration frequency peak in the z-axis direction and the X-axis direction as the spacing of the rectangular pit changes,and explore the variation rule of the average power with the increase of the rectangular pit span and the spacing.3.Establish the vehicle-soil soft pavement vibration system model,conduct hammer test on the wheel assembly,obtain the longitudinal and vertical transfer function curve of the system,and select the transfer function peak value as the transfer function characteristic value.At the same time,the measured value of the acceleration sensor is smoothen filtered,and the vibration signal given by the rectangular pit road is obtained by combining the vertical direction and longitudinal characteristic value.It is used to explore the law of longitudinal average force and vertical average force.4.Calculate the equivalent stiffness K and equivalent damping coefficient C of the vehicle-soil soft pavement vibration system.By integrating the vehicle response signal in the frequency domain,the time domain velocity signal ()and time domain displacement signal ()are obtained.According to the above parameters,the effective roughness ()of the soil soft pavement was obtained,and the frequency domain analysis was carried out on the ()obtained from 21 groups of experimental data.5.Figure out the spatial displacement power spectral density of the effective roughness of the soil soft pavement.It is mainly used to explore: 1.The law of effective roughness power spectral density value of soft pavement with the change of rectangular pit span.2.The spatial frequency corresponding to the peak point of effective unflatness of soft pavement shows a rule with the change of rectangular pit span and depth.3.Explore the frequency index setting range of rectangular pit pavement and the difference between it and hard pavement.