In electric vehicles, lightweight design is an important development objective for improving energy efficiency. Seat frame materials that are important for weight reduction use steel. In this study, weight optimization analysis was conducted by applying Almag, an aluminu-magnesium alloy material that offers excellent weight reduction while maintaining structural strength, to the seat frame. First, key stiffness members among the seat components were identified. Static strength analysis and natural frequency analysis were then performed on the steel seat frame. Based on the analysis results, a static optimization analysis was carried out for the application of the Almag material to achieve displacement levels equivalent to the static strength analysis. In addition, a dynamic optimization analysis was performed to maximize the natural frequency. Through these analyses, the optimal thicknesses of the seat back and cushion frame were determined.

Recently, Car weight reduction has become an important development goal to improve fuel efficiency. Car seat frame is a key part of the weight reduction. Existing steel seat frames have the advantages of high rigidity and durability, but have the disadvantage of heavy weight. Recently, Almag material, which are alloy of aluminum and magnesium, is attracting attention because of excellence in strength and weight reduction. At first, the core stiffness members of the seat frame are selected to optimize the weight of the seat frame. And then strength analysis and natural frequency analysis are performed for the existing steel seat frame and Almag seat frame. Based on these analysis results, optimal thickness of the Almag seat frame are determined by an automation program using a genetic algorithm.

The sub-frame is located on the lower body of a monocoque type vehicle and serves as an engine and suspension, and is an important object part that receives a lot of load. The existing press-type sub-frame has a large number of parts for assembling, which causes an increase in cost. Changing the machining form of this part from the existing press-type machining method to the hydro-forming machining method has the advantage of reducing the cost and weight at the same time due to the reduction of the process. Therefore, in this study, the purpose of this study is to change the design so that the sub-frame of the existing press type can be changed to the hydro-forming process method. To this end, we intend to present a design method by analyzing the effect on the rigidity of the sub-frame using the existing machining method through shape optimization analysis.