Research On Automotive Steering Wheel Based On Multidisciplinary Design Optimization

As one of main parts of steering system, the steering wheel determines theperformance of the overall steering system, thus having a great influence on vehicledriving performance. Therefore, as the key component of automotive parts, the designof the steering wheel is very important. The design of steering wheel needs to takeinto account many disciplines, including impact safety, NVH performance,lightweight and structural strength, etc. The traditional design method usuallyoptimizes one performance of the steering wheel at first, and then checks otherproperties. It is a modified repeatedly and checking repeatedly process, so thedevelopment cycle becomes longer. This serial design approach just starts from asingle discipline, ignoring the relationship between different disciplines. So it is notconducive to the development of engineering technology. Unlike the traditionaldesign method, the multidisciplinary design optimization (MDO) uses a specificframework to coordinate and control the interaction between the various disciplines,in this way parallel design can be achieved in various disciplines. As an engineeringresearch project, in this paper, based on the vehicle in design development phase, theMDO method was applied to design of the steering wheel skeleton without airbagconfiguration. According to the enterprise standards, this paper ultimately reachedmultidisciplinary design optimization by coordinating lightweight, impact safety andNVH performance of steering wheel.Firstly, based on analysis of the impact safety and NVH performance withsteering wheel, detailed finite element model of the steering wheel was established toexecute simulated analysis. Then the validity of the model was reasonably verifiedthrough the test. The comparation showed high consistence, indicating high reliabilityof the detailed finite element model. Since it takes a lot of time to establish and solvethe detailed finite element model, and the model is very difficult to modify foroptimization, the method of establishing a simplified model based on beam elementswas applied to make simulate study to facilitate design optimization of the steeringwheel. And the validity of this simplified model was reasonably verified. At the sametime, the result was compared with the result of detailed finite element model, andthe study showed that the simplified model of beam elements can improvecomputational efficiency while ensuring accuracy. In this dissertation, further based on the simplified model of beam elements,through the direct parameterization of cross-section on beam elements and the MDOthat adopted collaborative optimization(CO) framework, RBF approximation modelswere built instead of simulation model through the design of experiments in order tomeet performances of the impact safety and the NVH and to reach the goal ofminimum weight at the same time. The results show that: appling the simplifiedmodel of beam elements, the MDO approach not just guides forward design of thesteering wheel but achieves in parallel optimization design with two disciplines ofimpact safety and NVH performance, then the design cycle becomes shorter. Thestudy has a certain theoretical and practical significance on development andimprovement of other parts for the automotive, as a consequence, the engineeringpracticability is very strong.