关键词: 纯电动汽车, 轻量化设计, 生命周期分析, 多目标优化, 回收利用, 材料替代

Abstract: Although automobile lightweight can effectively reduce energy consumption and emissions during the usage stage, when the full life cycle of vehicles from material acquisition, material processing, parts processing and manufacturing, assembly, to use and recycling is taken into account, lightweight may not necessarily save energy and reduce emission and the overall costs may even increase. Previous evaluations of the lightweight effect of automotive products focus on the operation and use stages of automobiles, but fail to comprehensively consider the various stages of the entire vehicle life cycle and there is no multi-objective lightweight optimization research on the whole life cycle of automobiles. To address this problem, this paper proposes to consider comprehensively energy consumption, environmental emissions and costs of the full life cycle during the lightweight design phase, and conducts a lightweight life cycle multi-objective optimization study to achieve weight reduction, while reducing energy consumption, environmental emissions and costs throughout the whole life cycle of the automobiles. The conventional gasoline vehicle produced by a company and the pure electric vehicle developed on the same platform are selected as the empirical research objects. Based on the static life cycle evaluation model, the steel weight reduction ratio, the aluminum weight increase ratio and magnesium weight increase ratio are selected as design variables. Full life cycle energy consumption, greenhouse effect (GWP) and production cost are selected as three objectives. Through multi-objective optimization, when the steel weight of the pure electric vehicle and conventional gasoline vehicle decreases respectively by 6.44% and 6.41% ; the aluminum weight increases by 1% in both types of vehicles and the magnesium weight increases by 0.44% and 0.41%, respectively, the energy consumption for whole life cycle decreases by 3.20% and 3.21% and GWP decreases by 2.84% and 2.88%, respectively; and the production cost doesn't increase

Key words: electric vehicle, lightweight design, life cycle analysis, multi-objective optimization, recycling, material substitution