The composite material has high specific strength and specific stiffness, strong designability, and can achieve 20% increase in aircraft fuel efficiency; anti-fatigue and corrosion resistance, and can improve structural efficiency. The application requirements have led the research and development trend of aviation composite materials, which can improve the safety, economy, comfort and environmental protection of aircraft. Therefore, the research on composite materials and other new materials is becoming increasingly important.
However, the anisotropy and brittleness of the composite structure make it significantly different from conventional metal materials in terms of load deformation, damage mechanism and failure mode. Xu Jifeng, deputy chief designer of COMAC Beijing Civil Aircraft Technology Research Center, said that the inherent anisotropic mechanical properties of composite materials have brought difficulties to design and analysis. Compared with traditional metal structures, the application of composite materials on aircraft poses new technical challenges and brings a series of key technologies to be broken, such as connection analysis, stability, damage tolerance, fallability, large openings, lightning protection , Fire and flame resistance, anti-icing, interlayer analysis, etc.
Therefore, he believes that the future aircraft design will use breakthrough fuselage and propulsion technology to reduce aerodynamic drag and save fuel; focus on improving quiet environmental protection and comfort; flying at supersonic speeds and supersonic speeds, and the structural high temperature effect will be obvious. This requires an integrated structural design based on advanced materials, such as functional composite materials that require lighter, more durable, and higher temperature resistance; with the improvement of computer performance, overall optimization, aerodynamics, structure, and materials under the same framework will be comprehensively optimized, etc. .
At present, high-speed rail is facing two of the biggest dilemmas. One is to ensure safety, which must solve the impact and improve fatigue and corrosion resistance. The second is to improve efficiency. The same car pulls more passengers and makes the car lighter. This requires a lightweight solution.
Ding Sansan, deputy chief engineer of CRRC Qingdao Sifang Locomotive and Rolling Stock Co., Ltd. pointed out that the future development of rail vehicles is to pursue high-speed, high-efficiency, green, and intelligent. EMUs, these need lighter and stronger materials. In short, light weight as the core of the comprehensive solution is the foundation of future technology. It should focus on solving the performance contradictions with strength, stiffness, fatigue, corrosion, noise, and fire prevention, and look for balance-structural optimization, material optimization, integration optimization. At the same time, it is necessary to improve efficiency to meet the increasingly prominent bottlenecks of traditional structures and materials. Materials need to be lightweight, reduce impact, increase load, high weather resistance, high reliability, high availability, high life, and less maintenance. This will provide a rare opportunity for the application and promotion of CFRP technology.
Based on this, he suggested that the industry authorities strengthen the promotion and coordination of the CFRP composite materials industry, related enterprises and institutions advance in an orderly manner, and improve their survival and development capabilities. And demonstration project projects as early as possible. He believes that CFRP composite materials can solve many technical problems faced by high-speed trains with its performance advantages such as light weight, high strength, corrosion resistance, and high temperature resistance. After long-term scientific exploration, it will definitely overcome various technical and economic difficulties and be widely used. .
Compared with traditional body materials, carbon fiber composites have excellent mechanical properties, flexible structural design, and good corrosion resistance. They have a wide range of applications in the automotive field, such as body, chassis, interior, exterior, and power. System, etc. At present, the main application models of carbon fiber are BMW I3 / I8, Mercedes-Benz SLK200 carbon fiber limited edition, GM Corvette, Ford GT2016, Audi's new Q6e-TRON and so on.
Xiong Fei, General Manager of SZHT Carbon Fiber Co., Ltd. believes that the application of carbon fiber products in automobiles has six major advantages: First, the lightweight body, low carbon fiber density, 50% lighter weight than low carbon steel, and lighter weight than magnesium / aluminum alloy 30%; the second is high integration, free modeling, strong designability, streamlined, low surface cost, and reduced component types and tooling investment; the third is to overturn the production process, and the stamping and bonding process replaces stamping and welding, saving Investment in production lines, molds, and fixtures; Fourth, the car has good reliability and high fatigue strength of carbon fiber (up to 70% to 80% of the design load), which greatly improves the reliability of the car body; Fifth, the car has good comfort and more High vibration damping, which significantly improves the overall noise reduction effect of the car, and better comfort; Sixth, the car is high in safety, the center of gravity of the car is reduced after weight reduction, and the stability of the operation is improved. The collision energy absorption capacity is 6 to 7 times that of steel. 3 to 4 times that of aluminum.
He introduced in detail the choice of carbon fiber materials and product design and process technology routes, including material selection, process manufacturing, and post-processing costs. It is worth mentioning that he pointed out that structural optimization design of carbon fiber materials and products can be carried out from four aspects: size optimization, shape optimization, topology optimization, and morphology optimization.
In the face of increasingly stringent fuel consumption regulations, car companies around the world are taking proactive measures to promote energy saving and emission reduction of automotive products. Taking fuel vehicles as an example, weight reduction of the entire vehicle by 10% can reduce fuel consumption by 6% ~ 8% reduction in emissions, 10% reduction in braking distance, 5% reduction in braking distance, 8% reduction in acceleration time, 8% reduction in acceleration time, 7% increase in tire life, significantly improved fatigue life, and better overall vehicle safety performance.
The global automotive lightweight market was 717.2 billion in 2018, and the global automotive lightweight market is expected to reach 124.166 billion in 2020. In the next three years, China's automotive lightweight market will reach 500 billion, of which the new energy vehicle lightweight market is 35 billion. So, what is the path to achieve lightweight technology for new energy vehicles? Chen Pingsheng, executive chairman of the International Automobile Lightweight Green Technology Alliance, believes that safer, more energy-efficient, more environmentally friendly, intelligent manufacturing modular integration is needed, and optimization of component structure design And CAE simulation analysis, high-strength lightweight materials and advanced manufacturing technology quantitative application, to achieve mass production model lightweight. In addition, he also introduced several application cases of advanced composite materials in new energy production models, and pointed out that through the establishment of a carbon fiber composite material technology safety evaluation system, a common technology platform, and a collaborative innovation development mechanism for product lines, low-cost carbon fiber Composite materials will usher in broad market development prospects in the field of automotive structural industrialization.