Research On Acceleration Test Method Of Drive Axle Test Bench Based On Actual Load Spectrum

The automobile drive axle has the function of transmitting the speed and torque.It is one of the most important parts of the car,and its fatigue performance directly affects the service life of the car.At present,the evaluation of the drive axle in the automotive industry is mainly carried out through experiments.The repetitiveness of the car field test is poor,the cost is high,and the cycle is long,and the indoor bench test can make up for these defects,which has become the most important means of assessment and verification in the product development process.However,with the increasingly fierce market competition,higher requirements are placed on the product development cycle.How to quickly and accurately evaluate and verify products has become an urgent problem for enterprises.Based on this,this paper studies the method of strengthening the fatigue test of the drive axle based on the actual load spectrum,and further shortens the test period while ensuring the accuracy,which has strong engineering practical value.Firstly,according to the working condition and load spectrum characteristics of the automobile drive axle,referring to the existing load spectrum test method,the signals of the axle axle torque,speed,vehicle speed,transmission output torque and speed are selected as the acquisition targets.The wireless telemetry torque sensor and the imc high-performance data acquisition instrument and other reliable test equipment are the experimental basis,and a complete load spectrum real-time acquisition system is set up.Combined with the enterprise requirements and the test field load spectrum endurance test specification,a certain type of vehicle is driven by a vehicle drive axle.Load spectrum acquisition test.Then,the load spectrum preprocessing is carried out through data analysis,the load samples are extracted,and the torque signal of the actual load spectrum of the transaxle is selected as the analysis object.The distribution of load spectrum is obtained by means of mathematical statistics and time-frequency domain analysis.The four-point rain flow counting method is used to complete the statistical calculation of the load spectrum,and the target load is extrapolated to the extreme value and frequency according to the rain flow matrix method,and the load spectrum is extrapolated to the target cycle.According to Miner's cumulative fatigue damage principle,the load spectrum after external push based on the load spectrum damage equivalent principle is strengthened from the time domainand the frequency domain,and the experimentally equivalent enhanced load spectrum is obtained.Finally,the load spectrum enhancement results are selected,and the threshold is set according to the conover proportional coefficient method and the load amplitude,which is converted into a two-dimensional 8*7 load spectrum,and the two-dimensional load spectrum is converted into a one-dimensional seven-level load spectrum by using the variable mean method.Combined with the test bench standard and load cycle time,the bench test load spectrum was compiled and a test method for the drive axle bench reinforcement was established.