Application of carbon fiber composite materials in rail transit
The density of carbon fiber composite material is only 1.5-2g/cm3, which is 1/4 of steel and 1/2 of aluminum alloy. Compared with glass fiber materials, which are also composite materials, the application of carbon fiber composite materials can reduce the quality of the original equipment by more than 1/5, and have significant advantages in strength, stiffness and smoke toxicity. Although the research on carbon fiber composite materials in China started late, it has developed rapidly and has applications in many fields such as military industry and civil society. At present, the use of carbon fiber reinforced composite materials in the field of rail transit is mainly in some parts, such as body shells, hoods, light rail vehicle cab hoods, air shrouds, driver platforms, skirts, etc.
1. Body shell
In 2000, the French national railway company developed a double-decker high-speed train (TGV) trailer, and in 2010, the Korean Academy of Railway Sciences started to develop a tilting and pendulum train with an operating speed of 180km/h. Both train bodies are made of carbon fiber aluminum honeycomb. Sandwich material, a stainless steel skeleton is embedded in the composite layer to improve the structural rigidity of the car body, and finally the carbon fiber composite car body is obtained by integral molding of a large autoclave. Through this process, the total mass of the car body has been reduced by 40%, all performance indicators have fully met the design requirements, and it has been officially put into operation.
At the end of 2011, CRRC Qingdao Sifang Co., Ltd. developed a carbon fiber composite hood for a 500km/h high-speed test vehicle. The hood is made of a single-sided mold and a vacuum introduction process. The surface is designed with CFRP and aramid fiber reinforced optical fiber reinforced core (KFRP), and the middle is a foam sandwich. The whole is divided into two upper and lower cover bodies. Rubber filling, the upper and lower connecting parts are still made of carbon fiber composite materials.
Traditional bogies are mostly made of high-quality carbon steel, low-alloy low-carbon high-strength steel, weathering steel and other materials, which not only have high quality, but also increase the impact of dynamic load and accelerate the wear of contact surfaces. The density of carbon fiber composite materials is small, and the laminated structure of carbon fiber composite materials can be made into side beams of components by lamination, and the beams can be made of carbon fiber composite materials by winding molding, so that the overall bogie can be reduced by 30% compared with the traditional steel frame. %. For example, the CFRP subway bogie designed by the Korea Railway Research Institute in 2011, the German HLD-L and HLD-300 bogies, etc.
4. Equipment compartment
In 1999, Japan applied CFRP composite materials to the CFRP high-speed train roof and E4 cab jointly developed by the Railway Comprehensive Technology Research Institute and the East Japan Passenger Railway Company. The mass of each car was reduced by 300-500kg, accounting for 30%. Significant improvements have been made in terms of noise, body vibration and deformation. At the Berlin Rail Transit Exhibition, the CFRP frame side beam exhibited by Japan's Kawasaki Heavy Industries is 40% lower in quality than traditional metal beams, and the structure is simplified.
The curved beam of the box-girder structure and the beam of the I-beam structure are the main bearing structures of the equipment cabin. The cross-section of the curved beam is rectangular, and it is designed with CFRP prepreg cross-laying and is manufactured by a bag press molding process. The yield of the samples obtained by this process is high, and the manufacturing cost is controllable. The beam can be formed by vacuum-guided carbon fiber composite material, and the assembly method with other metal parts is mainly gluing and riveting; the skirt plate and the bottom plate are secondary load-bearing structural parts. The molding method of the carbon fiber composite material can choose the molding process, using the arc-shaped aramid honeycomb sandwich structure; the end plate can also choose the molding process, using the plane structure with reinforcing ribs, and using the unidirectional cloth layer inside to improve the transverse direction of the end plate. Vertical performance.
5. Other parts
The carbon fiber reinforced composite transition coupler developed by the German Voith company has a total mass of only 23kg, which is 50% lower than that of the steel coupler. The structure is simple and compact, and can be installed by one person. Carbon fiber brake pads have low braking noise; the braking curve is smooth and can withstand more thermal shock of braking friction; the wear resistance is good, the wear rate is lower than that of steel fiber brake pads, and the corrosion resistance is strong. For example, the high-speed train carbon fiber composite disc brakes of the German company KnoorBrems.
Carbon fiber composite materials show great advantages and good application prospects in the field of rail transit, ranging from decorative parts to high-speed trains with full carbon fiber composite materials. At present, carbon fiber composite materials should not only focus on the research and development of high-speed rail vehicles, provide toilets, doors and other body equipment and accessories, but also in-depth research and development and industrialization of material basic technologies, so as to better Promote the development of high-speed rail transit in China.