Simulation And Optimum Design Of Steel Wheel And Aluminum Alloy Wheel

As an important part of vehicle, the forces between ground and vehicle are transmitted by wheels in the process of moving. Failure of wheels will cause catastrophic accidents. Improving fatigue life of wheels excessively will lead to wheels getting heavy. Which not only weaken fuel economy, ride performance, but also deteriorate the cooling effect of wheels rapidly. Increased the chances of puncture wheels, and impaired the safety of vehicle. So the quality of wheels determine drivers’ safety directly.To improve fuel economy and ride comfort of vehicle, which limited by heavy life of wheels, the dissertation focus on enhancing performance of the commercial vehicle under the requirements of company. The main research works and achievements are as follows:(1) Discussed the forces, which comes from manufacture, assembly and daily working conditions, in detail, and found out that radial load and lateral load have a great impact on fatigue performance of two kinds of wheels.(2) Built finite element models for the two wheels of blot preload included or not respectively and compared the stress distribution of two models in each group under bending condition. It is conclude that the blot preload has great influence on the steel wheel, but neither for the aluminum alloy wheel. So only the simplified steel wheel model retaining the blot preload. On the basis of fatigue results of two wheels,take spoke thickness, air vent diameter of steel wheel, spoke thickness, weight reduction tank size of aluminum wheel etc as optimization parameters.(3) Studied on the mechanical properties and the simulation parameters of hyper-elastic tire in the radial condition. Established finite element models with and without air pressure for the two wheels respectively, analyzed the stress distribution rules of each model, obtained that air pressure have a great influence on stress distribution of two wheels by comparing the fatigue results. So reserved all characters of two wheel models in radial fatigue simulations. According to the fatigue results and assembly requirements, take the rim thickness of two wheels as optimization parameter.(4) To acquire the random excitation of rear wheel, modeled a Adams vehicle,then controlled it traveling on the 3D virtual pavement in accordance with actual situation under the condition of random vibration. Compared the natural frequency of two wheels with three times load frequency and combined the load characteristic of rear wheel, chose frequency response analysis on two wheels. Both wheels damaged seriously at low frequency loads inferred from fatigue result images. In order to reduce the damage, the first order frequency of two wheels need to be improved. Take the convex table size, the bulge transition arc radius, the hub weight reduction tank size and shape, the spoke cavity line of aluminum wheel etc as optimization parameters.(5) Summarized optimization parameters above, combined Latin hyper-cube design and orthogonal arrays method on two wheels experimental design, established response surface optimization models of two wheels based on experiment results.Under the premise of reasonable bending, radial and random fatigue life, striving for the lightest weight and the maximum modal value of wheels. Extracted the thickness of spoke and rim of steel wheel, the size of convex table, the radius of transition arc located on the spoke bulge, the height of spoke cavity line, the shape and size of weight reducing slot etc, as design variables. Using the genetic optimization algorithm,steel wheel weight dropped 24.04% and the first mode frequency enhanced 2.6%,alloy wheel weight declined 13.85% and the first mode frequency increased 7.6%.