The Development Of Automotive Fatigue Life Test Technique Based On The Real Road Load Spectrum

As the people’s living standard raising, the people’s demand for cars is becoming hiher and higher.At the same time, the people pay more attention on the quality, performance, appearance of the automobiles.How long a car can be used is a very imorptand parameter for most people.And it is also a key to show their product quality for automobile manufacturer.Car fatigue durability design not only has positive significance to the service life of the car, but also is of great significance for the safety and reliability of the car.It is one of the major issues that automobile industry is facing.Thus,the major car companies and research institutes launched the study of automobile structure fatigue life actively.Usually to evaluate the fatigue life there are three ways: real vehicle road test, bench test and Computer Simulation fatigue test.Real vehicle road test on reinforced pavement to test the fatigue life of the vehicle and its parts has important significance in vehicle development.But the test time is long and the efficiency is relatively low.So it needs the automobile manufacturer to spend a lot of manpower and material resources.Besides it has great influences on the early development progress.By collecting vehicle load domain signals in proving ground,and then using the signal in the virtual test bench test or a computer can greatly shorten the development time of fatigue life for cars,which brings huge economic benefits.Road load spectrum has an important meaning for vehicle fatigue test. Obtaining the accurate road load spectrum is the prerequisite for the fatigue test, the fatigue life prediction and fatigue design for vehicle.In this paper, the auto parts development of multiaxial fatigue life is based on the vehicle road load spectrum test. This paper takes a passenger car as the research object, the main achievements include the followings:① We select the reasonable arrangement for sensors’ location through demonstration analysis, and then we obtain first-hand road load spectrum through proving ground road spectrum data acquisition test.With a variety of sensors for rational allocation, we can maintain the accuracy of the collected data while ensuring the collection efficiency.In this process, we have set up the complete experimental process and obtained accurate information about the vehicle road test of vibration.② In order to meet the needs of subsequent fatigue durability test, we need to have the road load spectrum.First of all,we use the vehicle road load spectrum pretreatment method for initial adjustment, which can guarantee us get intact signal while eliminating obvious fault information.The pretreatment includes editing the road load spectrum to eliminate signal noise, correcting drift, filtering clutter signal, etc.③ We can accelerate the editor of the road load spectrum through the statistical results of road load spectrum and the analysis of the damage distribution.Determine how to edit the road load spectrum and make the edited fatigue test load spectrum can be directly used as test bench and computer virtual test input, which can meet the requirements of fatigue load performance development iteration.④ In this paper,we’ll prove that the results of computer virtual test and road test results consistency, then we’ll finish the load decomposition and calculate the fatigue life. On this basis, we can take durability analysis and optimization for chassis parts of the passenger car.