Vehicle lightweight designs are often defined as an optimization process with large design space and large number of design variables.To solve this type of problems,a quasi-optimization strategy which should cooperate with an optimization method was proposed. With the proposed strategy, the design space and design variables will be gradually reduced by analyzing the former optimization results.Application of the proposed strategy cooperating with hybrid and adaptive metamodel based global optimization method in rear frame system lightweight design demonstrates its effective,where

the weight of the rear frame is reduced in all three optimization process.Besides, the shortcomings were also discussed.

汽车轻量化问题通常被定义成设计空间较大、设计变量较多的优化问题。为解决这一问题，提出了准最优策略。该策略需要与最优化方法配合，对所提出的优化问题进行多次优化，通过对前一次优化结果进行分析，逐渐地减少设计变量、缩小设计空间,直到满足设计需要。将所提出的准最优策略与基于混合元模型的最优化方法相结合对某款车的后车架系统进行轻量化分析，系统的质量在三次优化中都有所减小，这一结果验证了该策略的有效性。此外，文章中也指出了准最优化策略的不足。

准最优策略, 混合元模型, 全局最优化, 轻量化, 后车架