The Life Prediction Of Automobile Front Axle Using Part Load Spectra

With furious competition in automobile market ,user's requirements for the reliability,harshness & safety become stronger and stronger , the complexity of component structure,the multiplicity and the irregularity of component service condition leads to more difficulty in its development process, the reliability of components has greater effect on economic benefit of enterprise ,all these mentioned above require that product development departments should apply modern fatigue & reliability design method in product design process ,to increase compete power in product market .Based on above causes ,the project is presented, the purposes of this paper are as follows:To predict product failure state,find and solve weak place of components in design as quickly as possible ,efficiently combining fatigue reliability test,structure analysis,reliability design works and etc. ,to produce a set of fatigue reliability development techniques of product ,to establish a kind of design & calculation method process basing on statistics and probability . all these works are done according to actual load spectra and fatigue life of automobile components.This paper has measured and got a long-8km-distance load spectra of automobile front axle under actual vehicle service condition, measured and got its P-S-N fatigue characteristic curve parameters, and predicted its service life , so that a strong support for design of automobile front axle has given.Main tasks of this project:Determined calibration coefficient of load vs. strain for measuring position using multi-direction load calibration method ;measured each load condition parameters for simulation automobile users ;packed up and concluded multi-load spectra correlative to user service distance ,basing on investigation of user service condition and actual measuring load parameters of automobile components ,determined load levels and load magnitude for test rig of getting P-S-N fatigue characteristic curve parameters, produced P-S-N fatigue characteristic curve parameters by using group test method,determining least test samples for each level load,dealing with strange data and valid test data ,regressed all kind of P-S-N fatigue characteristic curve of different probability using power function for three parameters to deal with fatigue life test data of front axle , basing on the life under different level load of test rig, predicted service life of automobile front axle under a long-80,000km-distance load spectra of user service condition using fatigue liner accumulative damage thesis.