Strength Analysis and Structural Optimization of Multi-Piece Wheels for Heavy Vehicles

The wheel acts as a rotating part of the un-sprung mass, whose weight reduction brings significantly higher energy-saving effect than that of non-rotating parts. However, a lightweight design can only be acceptable if economical use of materials does not influence the requirements concerning safety and durability. Due to the capacity for high payloads and harsh operating conditions, and the simple demounting tire operation, multi-piece wheels are widely used on heavy vehicles and construction machinery. The customer usage data indicates that the failure rate of one certain multi-piece wheel (type 8.5-20) for heavy vehicles is greatly low because of excessive strength of the wheel. It is believed that there is potential for weight reduction of the wheel. In order to improve material efficiency, the strength analysis and lightweight design of the multi-piece wheel is studied in this paper. Firstly, the characteristic of the wheel under bending load and radial load is simulated by using finite element analysis. Based on the obtained stress distribution and critical areas, the rim is selected as the optimized object. The analysis results show low stress on the rim area under bending load. It is reasonable to optimize the structure of the rim on the basis of its performance under radial load. The 21 geometric parameters of the rim cross-section are chosen as design variables to minimize the weight subject to strength and stiffness constraints. The parametric three-dimensional model of the rim is built, and the automatic calculation of stress, displacement and weight is realized by program. SolidWorks, Abaqus and Excel are integrated on the optimization design platform to automate the optimum workflow based on the approximation loop strategy. This strategy packed in Exploration component of Isight is an iterative algorithm which creates an approximation and executes an optimization plan multiple times, updating the approximation automatically between each cycle if deemed necessary. The selected numerical optimization method of solution is sequential quadratic programming NLPQLP. The algorithm can decrease the number of samples used for directly establishing accurate approximation model in high-dimensional optimization problems. Eventually, the optimal results show that a good lightweight design effect is acquired, and the weight of the rim is reduced by 6.5% under requirements of strength and stiffness. The optimal process of the rim is efficient because of less calculation of finite element model and fast convergence with the above strategy. The research provides a fast method for the optimal design of wheels.