According to the data analysis of the China Association of automobile manufacturers, the global auto sales in 2020 were 77.9712 million, a decrease of 13.77% from 90.4237 million in 2019. The production and sales volume data were similar to that in 2011, and China's auto sales ranked first with 25.311 million. With the increasing number of cars, the carbon emissions of fuel vehicles are increasing. Under the dual requirements of energy conservation and environmental protection, in addition to promoting the development of new energy vehicles, lightweight design can not be underestimated. In order to reduce carbon emissions, in addition to further promoting the promotion and application of new energy vehicles, it is urgent to promote the development of fuel vehicles in China towards high-quality, lightweight and low emissions. Promoting energy conservation and emission reduction is an important measure to achieve the goals of "carbon peaking" and "carbon neutralization", and it is also the main direction of the sustainable development of the automotive industry. Lightweight design is undoubtedly one of the most effective methods for automotive energy conservation and emission reduction. As the weight of the vehicle body accounts for a relatively heavy proportion of the vehicle weight, the lightweight of the vehicle body is very important to the weight reduction of the whole vehicle.
The selection of appropriate materials has an important impact on the weight of the car body. The lightweight of materials directly affects the lightweight of the car body. On the premise of ensuring that the performance of the car body is not affected, the car body materials with low cost, good sustainability and easy processing and molding are preferred. Aluminum magnesium alloy in the applications of vehicle body is widly used in vhicle industry.
Aluminum has large reserves, good energy absorption effect and formability, and the density of aluminum itself is low, with significant lightweight effect. Compared with high-strength steel, aluminum has obvious advantages in thermal conductivity and corrosion resistance, coupled with good processing performance, making it one of the most widely used lightweight materials. At present, aluminum alloy is favored by major automobile manufacturers and is widely used in car bodies. It even shows all aluminum bodies, such as Audi R8 and the fourth generation Range Rover, which are mainly used in car cowl, middle channel, wheel hub and other positions.
Mgnesium alloy is also a kind of alloy material with outstanding advantages. Its quality is only one quarter of that of iron products and two thirds of that of aluminum products, but its strength is comparable to that of titanium. Based on its good shock absorption, conductivity, heat conductivity and die-casting properties, cast magnesium alloys are widely used in brake brackets, bracket assemblies, cam covers and other parts. Magnesium is very active and easy to be oxidized and corroded, and its performance needs to be improved. If magnesium is widely used in the body structure, it needs further development and research.
Structural optimization design is the key to body lightweight. At the beginning of the development of body lightweight, it depends more on the repeated trial and error of engineers and technicians, and often takes a long time to develop and has little effect. With the continuous improvement of lightweight technology, structural optimization design is also gradually developing in depth. Through numerical methods such as finite element, computer-aided technology and iterative calculation, the optimal structural scheme is found, which not only improves the design efficiency and quality, but also saves human and financial costs.
