Multi-material and multi-joint topology optimization for automotive lightweight design

随着政府对燃油效率和二氧化碳排放的新规定，汽车制造商面临着大幅减少车辆质量的巨大压力。例如，由于强制实施的企业平均燃油经济性(CAFE)，原始设备制造商必须通过从2016年到2025年的一系列措施显著提高车辆里程。燃油经济性要求将改变汽车设计和制造的方式，因为汽车制造商正在寻找一切可能的减轻重量的方法。拓扑优化决定了在保持重要性能特性的同时最小化重量的材料的最佳布局或分布；这是最有效和最有前途的减轻车辆重量的设计技术之一。在汽车开发中，各种轻质材料的使用正在迅速增加，这就提出了一个新的设计挑战：“多种材料的最佳使用和分配以及最佳的连接方法是什么？”传统的优化方法不能很好地满足这一挑战，迫切需要开发一种有效的方法来确定多种不同材料及其连接方法的最佳使用。本研究的目标是：(1)通过开发先进的多材料连接设计和连接方法的拓扑优化方法，确定采用混合材料和各种连接方法的下一代汽车底盘连接策略的优化设计。通过开发多材料和多连接拓扑优化的新技术，加拿大通用汽车公司将确定轻型卡车梯形底盘车架的优化设计。目标是在不牺牲车架强度或刚度的情况下，总重量节省30%。该项目的最终交付成果是下一代梯架组件的生产准备设计，以及通用汽车加拿大公司在其早期车辆架构开发阶段使用的优化软件模块。

With new government regulations on fuel efficiency and C02 emissions, automotive manufacturers are undertremendous pressure to reduce vehicle mass drastically. As an example, OEMs have to significantly improve vehiclemileage through a series of steps beginning in 2016 through to 2025 due to the mandated Corporate Average FuelEconomy (CAFE). The fuel economy requirements will transform the way in which vehicles are designed andmanufactured as automakers are looking at every possible means to reduce weight.Topology optimization determines the optimum layout or distribution of material that minimizes weight while maintainingimportant performance characteristics; and this is one of the most effective and promising design techniques forreducing vehicle weight. The use of various lightweight materials in vehicle development is rapidly increasing, and thisraises a new design challenge: "What are the optimum use and distribution of multiple materials and the optimum joiningmethods?" Conventional optimization approaches are ill equipped for this challenge, and it is imperative to develop aneffective approach that can determine the optimum use of the multiple, dissimilar materials and their joining methods.The objectives of this research are (1) to determine optimum designs of next generation vehicle chassis joiningstrategies which utilize mixed materials and various joining methods (2) by developing advanced topology optimizationapproaches for multiple material joint designs and joining methods.By developing new techniques for multi-material and multi-joint topology optimization, optimized designs will bedetermined for the ladder chassis frame of a light-duty truck by General Motors of Canada. A total weight savings of30% is targeted, without sacrificing the strength or stiffness of the frame. The final deliverables for the project areproduction ready designs for next generation ladder frame assemblies as well as optimization-software modules for useby GM Canada in its early vehicle architecture development stage.