Research On Durability Of Vehicle Based On 6-DOF Spindle-coupled Road Simulation Test Bench

In order to guarantee the quality and shorten the research and development period,automobile manufacturers have to carry out fatigue durability test on new vehicle.In this paper,a domestic vehicle is studied and the test data is acquired in Beijing tongxian proving ground.6-DOF road simulation test bench has the advantages that it can accelerate the whole vehicle development period and optimize the design of the vehicle,based on it,the vehicle fatigue durability test method is studied.The full text consists of six parts.The first chapter is the introduction,which briefly introduces the development of vehicle fatigue durability test at home and abroad.Through the introduction and comparison of various test methods of vehicle fatigue durability,the advantages and disadvantages of various test methods are summarized.Finally,the main research content of this paper is introduced,and the method of laboratory bench test is the basis of this paper.The second chapter is the collection of road load data,which is of great significance to the study of vehicle fatigue durability test,and the acquisition of accurate road load data is the precondition for fatigue durability test,fatigue life prediction and fatigue design of vehicle.In this chapter,the road load data acquisition scheme is proposed,and the number of collection channels,sensor types,and sensor placement are planned.After that,the durability program of the test is planned,including the selection of test road,test vehicle payload and test vehicle speed.Based on the above planning,the road load data acquisition of test vehicle in the designated proving ground is completed,so that the collected data can meet the needs of subsequent bench test and CAE analysis.The third chapter is load data analysis,editing and processing.In order to meet the needs of subsequent bench test and CAE analysis,it is necessary to process the road load data.Firstly,the pretreatment method is used to adjust the load data of the vehicle,so that some obvious fault information can be eliminated.The operations include trend removal,spike detection,etc.Secondly,the rationality of the load data is checked.Finally,by calculating the relative damage of each road,the target events for laboratory bench test are obtained.The fourth chapter is the laboratory bench durability test for the whole vehicle.In this chapter,the current situation of the road simulation test bench at home and abroad is summarized,and the development of bench drive file is introduced.The iteration results are evaluated by comparing the time domain signal,frequency domain signal and relative damage.The drive signal obtained by iteration is edited into a bench program and played.By comparing the bench test results with CAE simulation results and road test results,the correlation between bench test method and other experimental methods is verified.The fifth chapter is about the influence of control strategy on iteration results.The core of iteration with load data is to obtain the high quality of the system frequency response function,which will affect the accuracy of subsequent iteration,while the quality of the system frequency response function obtained corresponding different control strategies are different.This chapter mainly compares the effects of two different control strategies on the iteration results.Control strategy A: wheel forces are choose as control channels.Control strategy B: wheel forces,accelerations,displacements and strain gauge are choose as control channels.In terms of iteration accuracy,under control strategy A,the RMS error of wheel force channels is smaller,and the whole iteration process takes less time.In terms of real roads reproduction,control strategy B can not only reproduce the external forces on the wheels,but also reproduce the internal forces of the whole vehicle by controlling the strain gauge channels of the connecting rods.In addition,by controlling the acceleration channel and suspension displacement channel,the simulated vehicle motion is more realistic.Therefore,control strategy B is better than control strategy A.The sixth chapter summarizes the research of this paper and looks forward to the future research direction.