| Steering knuckle is the critical component of the steering system of the vehicle.Suspension system, front axle, steering system and brake system of the vehicle are allconnected by Steering knuckle, it is the steering knuckle that sustains the front weight of thevehicle and rotates the wheels of the vehicle. Reliability of the knuckle has an effect on thereliability of the vehicle and the safety of the people in vehicles, so it has a very importantposition in auto component industry. When the vehicle is moving, the steering knuckle maybe impacted by random loadings. Besides, the structure parameters and material properties ofthe knuckle are all uncertain. The existence of these random factors makes it difficult toaccurately estimate the reliability of the knuckle. This paper executed the reliability andsensibility analysis of steering knuckle using Monte Carlo Finite Element Method,considering of the affection of random factors like Geometric and material parameters. Aftersensitivity analysis, different influences of objective function by various parameters areobtained, and then the appropriate parameters can be selected for the optimization of steeringknuckle. Compared with the traditional design, this method not only prevents to selectparameters that not necessary, but also can help to choose the more important parameters. Themain work and research results are as follows:1. The parametric model of a steering knuckle was firstly established by ANSYSParametric Design Language (APDL).Then, the static analysis and modal analysis of steeringknuckle were carried out. The results of static analysis indicate that this steering knuckle cansatisfy the strength requirements, and the results of modal analysis indicate that this steeringknuckle won’t resonance when the vehicle is moving or under idle condition.2. The reliability analysis of the knuckle was executed. The PDS module of ANSYSsoftware is applied to reliability analysis of the steering knuckle, avoiding the difficult ofobtaining the limit state function of complex structures. This paper counted in the randominfluential factors of the fatigue life, such as material heterogeneity, loads randomness, etc. which makes the simulations more like the real considerations, thus makes the results morereliable. The results showed that under combination working conditions the reliability ofknuckle is0.996.3. The sensitivity analysis of the knuckle was executed. The influence degree of randomparameters on the steering knuckle stress limit state equation is analyzed, and how to improvethe stress concentration of knuckle is discussed. Meanwhile, the sensitivity analysis of thedesign parameters on overall weight is carried out. The most sensitive design parameters isfound out, so that it can provide reference for further optimize the structure of the knuckle.4. ANSYS software is used in the steering knuckle structural optimization. Based on thesensitivity analysis results, the appropriate design variables were selected to optimize theconnecting rod, reducing the overall weight of knuckle as optimization object, selectingstrength, stiffness, and frequency of state conditions and geometric boundary conditions as theconstraints. |
