The Test Effect Research Of Auto Proving Ground

No matter how powerful of the CAE simulation capability the vehicle test in provingground can’t be replaced during the vehicle development. At present the proving grounds arestill the main test sites for the vehicle design or manufacturing companies. In China, theautomobile industry develops fast, but only few companies have their own proving groundsfor the vehicle’s R&D. Generally speaking they all use the public proving grounds to do thetests.Based on the data of many-year vehicle developing validation and evaluation,combining with a platform development and validation projects, referring both a northernand a southern proving ground test specifications, collecting the platform’s typicalcomponents road load spectrum on both proving grounds, getting the rear twist beam’s S-Ncurves from the rig tests, and doing statistics, comparison and analysis of the Weibulldistribution and Miner fatigue cumulative damage theory and Rain flow counting technique,this article concluded Weibull distribution and proved the internal reason for the differenttest effects in a northern and a southern proving ground from the point of components andparts load spectrum.This article’s main conclusions are as follows:1. Relatively speaking, the test road types of a northern auto proving ground are lessthan a southern proving ground, but the damage ability to the vehicle is stronger. The sameplatform vehicle test on the two proving grounds will get different test incident Weibulldistribution. The test effect relation between the two proving grounds is about2.1from themathematical expectation. This indicates that the test effect relation of the two provinggrounds is relative definite.2. The washboard road is the typical excitation source, this frequency is easy to be closeto or overlap the vehicle or parts resonance frequency, which finally result in the key partsmodel stress too big and damage for the resonance. The simulation results of the twist beam system ADAMS model and the load spectrum calculation and analysis prove this pointtogether. For this purpose this article definite the washboard road as the road sensitive factor.It is very important to do rational technical driving specifications for the test vehicle. It willcause distortion in deficiency or overdo if it is not fit the developing vehicles, which willfinally cause the big difference in test effect.3. By measuring the load spectrum of the vehicles under the multiple workingconditions on the two proving grounds, getting the rear twist beam’s S-N curves from twistand bending rig tests, and analyzing typical channels fatigue life through Miner fatiguecumulative damage theory, the twist beam’s bending and twist fatigue life tested from anorthern and a southern proving ground spectrum are found to follow different Weibulldistributions, with the mathematical expectation ratios of fatigue damage life are2.0and11.7.4. The test effect is different because the two proving grounds road condition and thedriving specifications. Washboard road and the twist road can make the biggest fatiguedamage on the test vehicle, and a northern proving ground can produce bigger damage on thevehicle than a southern proving ground. Relatively speaking a southern proving ground’sdamage on the vehicle is mild and balance. But it is hard to make out a reasonable technicalspecification of vehicle test because the two proving grounds’ test road layout and drivingrequirement.In a word, in order to ensure the scientific and efficient every company should examineand distinguish the proving ground test conditions and specifications, make a targetedselection or improvement for the vehicle developing test.