Automobiles are one of the important sources of urban air pollution. With people's attention to air quality and the continuous depletion of energy, energy conservation and emission reduction have become a key issue in the automobile industry. Steel materials on automobiles account for 3/4 of the vehicle's weight. If carbon fiber materials can be used to fully replace steel, it will have a greater impact on automobile fuel economy and carbon dioxide emissions. Therefore, the lightweight of automobiles is an important method to realize energy saving and emission reduction. If you want to reduce the weight of the car, you must either optimize the structure of the car or use lightweight composite materials. Carbon fiber composite material is currently the material with the highest specific modulus and specific stiffness among composite materials. At the same time, it also has the characteristics of high temperature resistance, good weather resistance, and strong designability. It is an ideal material to realize the lightweight of automobile hood.
The layup design of carbon fiber composite materials generally uses the principle of balanced and symmetrical laying, which can effectively avoid the warpage and deformation of the shell structure. The layup design of carbon fiber cloth can make maximum use of the high strength and rigidity of the carbon fiber direction. As the outer pole cover of the car body, the automobile hood needs a certain degree of impact resistance in order to protect the parts in the engine compartment. And laying ±45° on the surface can obviously improve the impact resistance of the composite material, which is conducive to load spread. Therefore, the structure of carbon fiber composite materials is finally defined as the structure to meet the requirements of the hood. The shape of the hood is affected by the shape of the whole vehicle. Under the premise that the shape of the hood cannot be changed, the size optimization method is selected, and the thickness of the carbon fiber composite material is used as a variable. Under the premise of meeting the rigidity requirements, a hood that meets the design requirements is obtained structure.
The design of the internal reinforcement ribs of carbon fiber composite material, the lateral stiffness of the carbon fiber hood is greater than that of the original steel hood, and the torsional stiffness is only reduced by 13.28%, which meets the design requirements. Under the premise that the shape of the hood cannot be changed. Based on the size optimization technology, combined with the design requirements of the carbon fiber hood, it can be verified through the structural design of the carbon fiber composite material and the structural design of the hood stiffener, as well as the stiffness performance simulation analysis. The feasibility of carbon fiber material hood in actual promotion.
The hood is not only used to beautify the car, it can protect the engine of the car, and also absorb kinetic energy to protect the passengers in the event of an accident, so the performance of the hood is very important for the safety of the car. Traditional hoods mostly use metal materials such as aluminum alloy or steel plate. Such materials have the disadvantage of being too heavy and easy to corrode. However, the excellent performance of carbon fiber materials has great advantages over metal materials.
Compared with the metal hood, the weight advantage of the hood made of carbon fiber composite material is very obvious, which can reduce the weight by about 30%, which makes the car more flexible and consumes less fuel. In terms of safety, the strength of carbon fiber composite is better than that of metal, and the fiber tensile strength can reach 3000MPa, which can better protect the car. In addition, the carbon fiber material is resistant to acid and alkali, salt spray, and has strong environmental adaptability and will not rust. The texture of the carbon fiber products is beautiful and generous, and the polished treatment has a good texture. The material has strong plasticity and can meet the needs of individual customization.
At present, carbon fiber hoods are used in many models. Both safety and aesthetics are due to the traditional hood. The bright and clear texture and clear texture can make the car the focus of the road.