Nonlinear FEA And Optimization Of Self Dumping Driving Axle Housing

Driving axle housing is main mechanical part of heavy vehicle; the nearly full weight of body is supported. The design of the driving axle housing is closely related with the vehicle's safety. In the past , tight fit of the driving axle housing and half axle tube cannot be computed exactly ,that leads to the bad reliability, low safety factor, invalid within design life ahead of schedule. With the increasing perfection of modern FEA technology, the tight fit of the driving axle housing is numerically simulated and optimized under the certain precision.This paper firstly summarizes study actuality of nonlinear contact theory and over tight fit and FEA optimization, on the base of this, the first trial analyses is applied on the object of 13T self-dumping truck about the nonlinear question by the software MSC. Marc, the danger zones are found ; Lamei formula based on the thick wall cylinder is deducted for contrasting with the traditional computed method, the elasticity mechanics analytic solution of the over tight fit is gained, comparing with numerical result ,the limit of Lamei formula is discussed ,the accuracy of the numerical simulation is proved; consulting the invalid records of the product company , Invalid zones tallies with result of the FEA ,that prove that the effect of simulation is comparative ideal, FEA method fully suits this project.Based on studying the nonlinear contact of the driving axle housing, according to the actual work situation of the driving axle housing, three groups of trials is divided, mechanical action of the loaded housing is analyzed in detail .the valid interference closure range of the driving axle housing and half axle tube is obtained. The dimension tolerance of the driving axle housing and half axle tube is redesigned according to this range of tolerance.Based on the above valid range of the tolerance, the reliability of contacting zone before and after improved is computed detailedly by the knowledge of reliability, the result show that the reliability is improved clearly.In the above analyses, the main body of the driving axle housing existed the stress concentration, this zone belongs to danger zones, in this paper this zone is applied on shape optimization to decrease the stress concentration. The effect of nonlinear factor is weak to this zone by argumentation of test design method, so the linear model is substituted for the nonlinear model. The shape optimization of the housing is finished by advanced linear optimization software OPTISTRUCT, the result show that the stress concentration is improved clearly.The life of the driving axle housing is computed by the FEA software MSC.FATIGUE; contrast the change of the life of the housing before and after optimization lastly in this paper.The original design drawing of this project is improved by finite element simulation and optimization, it is significant to the design of driving axle housing .The rigorous demonstration and effective testify is combined in the course of simulation, the question of the driving axle housing design is perfectly solved.