Structure Design And Numerical Simulation Of Aluminum Alloy Automobile Steering

Steering knuckle is one of the important parts of automobile suspension system, it connects the wheels and suspension control arm, meanwhile is also an installation support of steering knuckle arm and the brake calliper, bearing the front axle load,supports and drives the front wheel to rotate around the main pin leaving the vehicle steering to ensure the vehicle stability driving and sensitive transfer direction of travel.In the vehicle running state, it can bear the load condition is complex and changeable.So it need to have a greater stiffness and sufficient strength and safety factor; at the same time also as far as possible to reduce weight,in order to meet the requirements of handling stability and lightweight of vehicle.In this paper,we chooses the aluminium alloy as the material steering knuckle.On the one hand,from optimization of auto weight reduction and improving fuel economy.On the other hand,the processing cost of aluminum alloy is far less than the processing cost of the iron.Therefore, this article from the perspective of the automotive lightweight to research the aluminum steering knuckle,study the structure of aluminum alloy steering, constraints and load conditions,research on the strength analysis, modal analysis and optimal design of the steering knuckle, and the forming process and the influence of process parameters on the microstructure is analyzed, provides effective reference for actual production. The research contents of this paper are as follows:According to the nominal load calculation method of three typical conditions of vehicle driving, analyzes the force in various condition,and obtained the calculation load under various working conditions;Obtained the steering knuckle stress contours and deformation map under three typical working conditions and two combination conditions by using the ANSYS static structure analysis module, and analyzed steering knuckle load and stress distribution of section under various operating conditions;according to the traditional design method calculate stress value of sideslip conditions on the dangerous section, compared with the traditional design values,validate the analysis and the calculation model is correct and feasible in this paper, and the steering knuckle meets the strength requirements.On the theory of modal analysis is studied in this paper, and then combined with the structural dynamics analysis module of ANSYS makes modal analysis about aluminum knuckle, calculation and extract the vibration characteristics of steeringknuckle, obtained ten order vibration mode and natural frequency of steering knuckle.Through the modal analysis, we see the first-order natural frequency section for164.06 Hz is much larger than the excitation frequency, and the steering knuckle structure vibration is relatively stable, keep the whole structure tends to be steady.The optimization module of ANSYS and the optimization theory are studied,according to the steering knuckle structure characteristics and practical usage has formulated the main design ideas and steps of the optimization designs;The mathematical model of optimization select the geometric dimensions and coordinate as design variables, in order to alleviate the weight as objective function, to meet the strength, stiffness etc. state conditions and geometric boundary conditions as constraints;using ANSYS optimization design module make an optimization on steering pull arm and the upper block, after optimization steering knuckle totally reduce weight of 13.1%,materials are fully utilized, and the stress concentration effectively improved. At the same time, compared with the steel steering knuckle, knuckle of aluminum alloy is a weight loss of 70.3%.The detailed research has been carried on the forming process of the steering knuckle, and then combined with the software of DEFORM made the simulation analysis on aluminum alloy steering knuckle in several expected forming scheme,finally determinate the rational forming process; because the temperature for a certain,so the simulation analysis and comparison of influence of the compressor speed on the steering knuckle grain and streamline is carried out, to determine the reasonable compressor speed, and forming simulation of this compressor speed is carried out,founded that the recrystallization grain size is smallest, the mechanical properties is best.