Research and application project of key technologies for lightweight structure of electric vehicles through evaluation of a number of magnesium alloy achievements

On February 23, the High Technology Research and Development Center of the Ministry of Science and Technology held a video conference in Beijing to organize experts to conduct a comprehensive performance evaluation of the 13th five-year National key Research and Development Program "New Energy vehicles", the key project "Research and Application of structural lightweight key Technologies of Electric vehicles" undertaken by the Chinese Society of Automotive Engineering.

Wang Xiang, project director of the key Special Management Office of the High Technology Research and Development Center of the Ministry of Science and Technology, presided over the meeting, which was composed of 15 technical and financial experts to question and evaluate the project from both technical and financial aspects. Zhang Ning, the special secretary-general and project manager of the Chinese Society of Automotive Engineering, as well as the project leaders, project backbones and financial personnel of 31 enterprises participating in the project attended the meeting and answered the experts' questions.

At the meeting, Wang Xiang, director of the High Technology Center, introduced the overall requirements for performance evaluation of national key R & D projects, and Lian Yubo, head of the overall group of experts, read out the work requirements of the technical expert group. Dong Lianlian, the deputy head of the financial expert group, read out the work requirements of the financial expert group.

Zhang Ning reported the project results to the expert group on behalf of the project team, and showed the trial-produced samples of carbon fiber rear floor, forged aluminum alloy wheels, magnesium alloy wheels, warm-formed B-columns, thermoformed B-columns, magnesium alloy front brackets, die-casting shock absorber tower brackets and other projects to the expert group.

After a collegial discussion on the report and defense of the person in charge and the project undertaking unit, the project expert group agreed that The project "Research and Application of key Technologies for lightweight of Electric vehicle structure" focuses on carbon fiber composite materials, aluminum alloy and magnesium alloy, application of ultra-high strength steel, lightweight optimization design of electric vehicle with new architecture, connection of dissimilar materials, construction level evaluation of lightweight database for electric vehicles, and standard formulation. Research work has been carried out, and a series of research results have been achieved. These technological innovations contribute to the development of lightweight technology and the promotion of product competitiveness of electric vehicles in China, and play an important supporting role in the realization of key special goals.

The specific achievements of the project "Research and Application of key Technologies for structural lightweight of Electric vehicles" are as follows:

1. A new structure electric vehicle structure-material-performance integrated lightweight multi-objective optimization design method is established, and the optimized car body coupling system composed of aluminum alloy chassis frame and carbon fiber passenger cabin is compared with the original steel full-load body-in-white body. 33.1% weight loss.

two。 Breaking through the integrated design technology of large carbon fiber body structures, the weight of the developed floor assembly is 46.91% less than that of steel floor assembly.

3. Breaking through the integrated design technology of complex thin-wall die-casting aluminum alloy structures, the developed shock absorber bearing can reduce weight by 44.7% compared with the steel assembly, increase the stiffness by more than 17.6%, and the air content of the casting is less than 2.37ml / 100g. The developed forged aluminum wheel hub achieves a weight reduction of 13.2% relative to the casting hub.

4. Breaking through the integrated design technology of large and complex thin-walled corrosion-resistant magnesium alloy structures, the developed 16-inch magnesium alloy wheels reduced weight by 29% compared with cast aluminum alloy of the same size, and the developed magnesium alloy front-end components reduced weight by 66.98% compared with steel front-end components. The corrosion rate of bare materials of magnesium alloy parts is lower than that of 1.2mm/a.

5. The evaluation methods of delayed fracture and cold bending resistance of ultra-high strength steel are established, on the basis of which high-strength and lightweight door anti-collision beam and B-column strengthening plate are developed.

6. The mathematical model of dissimilar material connection structure and the numerical analysis and evaluation method of connection performance and fatigue failure are established.

7. The lightweight evaluation method of electric vehicle, body and typical parts is established, the lightweight common technical database of electric vehicle is constructed, and 19 lightweight technical group standards are formulated and issued.

The project "Research and Application of key Technologies for lightweight of Electric vehicle structure" successfully passed the comprehensive performance evaluation of the project of the Ministry of Science and Technology, and the relevant results were highly affirmed by the expert group. At the same time, the expert group also put forward higher requirements, hoping that the project team members will continue to promote the industrial application of technological achievements and promote the rapid development of lightweight technology in our country.