The Study Of Load Decomposition Technique Based On Virtual Spindle Coupled Road Simulator

The development cycle of vehicle fatigue and durability performance has been shortened,and it has gradually evolved into a basic process that the CAE analysis carried out in the early stage,and verification implemented by both rig test and road test。In the early stage of development,the component fatigue and durability analysis needs to input the boundary load based on the real durable road surface,and the vehicle fatigue load decomposition have great significance.Combining a passenger car project in actual product development,the fatigue load decomposition is studied in this paper.A virtual fatigue and durability test system based on vehicle multi-body dynamic model and virtual spindle coupling road simulator system is established,and the load spectrum collected by the vehicle in the proving ground is used as the model input condition,the calculated loads of the components or subsystems of the vehicle model are extracted.Results are compared with the experimental data,the research indicates that the load spectrums of the main components are basically consistent in the time domain,and the load decomposition result is good.The relative pseudo-damage retention ratio of each component under all events is between 0.52 and 1.85,it meets the requirements for vehicle durability development.Taking the rock block road as the analysis condition and comparing with the virtual iterative load decomposition technology,the results show that the load decomposition accuracy based on the virtual spindle coupled road simulator is 96.55%,which is significantly higher than the virtual iterative load decomposition accuracy of 85.66%,and the calculation speed is improved significantly.The research shows that the load accuracy extracted by the virtual spindle coupled road simulator can not only meet the fatigue and durability analysis requirements of the whole vehicle and parts,but also significantly shorten the fatigue and durability performance development cycle of the whole vehicle.The innovations of this paper mainly include the following four aspects:1)A vehicle assembly model based on the virtual spindle coupled road simulator is established.This model can reproduce the endurance test process of the MTS329 spindle coupled road simulator,and a unique body control mode is adopted in this vehicle simulation model,which can effectively suppress the drift phenomenon.2)The advanced vehicle fatigue load decomposition process is applied.Firstly,road spectrum acquisition is carried out in the proving ground,and the load spectrum editing process is applied.Secondly,the vehicle rigid-flexible coupled multi-body dynamics model and the spindle coupled road simulator are established by using ADAMS/Car,and the assembly of the whole vehicle model is completed by using the virtual server.Then fatigue load is extracted by loading road load spectrum in the ADAMS environment.3)A variety of load decomposition accuracy verification methods are applied,including time domain contrast analysis,frequency domain contrast analysis,and relative pseudo-damage retention ratio threshold determination.4)Compared with the virtual iterative load decomposition technique,it is proved that the load decomposition technique based on virtual spindle coupled road simulator is faster and more accurate.