Composite materials are prepared by combining two or more other materials together, so they can complement and improve each other, but also maintain their unique characteristics in the final product.
The main application form of carbon fiber is as a reinforcement for resin materials, and the resulting carbon fiber reinforced resin (CFRP) has excellent comprehensive properties. Due to its excellent performance, composite materials have been widely used in various fields. It has practical and potential applications in various fields such as missiles, space platforms and launch vehicles, aircraft, advanced ships, rail transit vehicles, electric vehicles, trucks, wind turbine blades, fuel cells, power cables, pressure vessels, uranium enrichment ultra high speed centrifuges, special tubes, public infrastructure, medical and industrial equipment, sports and leisure products, and fashionable daily necessities.
CFRP is widely used as the main load-bearing structural material in large advanced aircraft. And in the recently developed new airships, CFRP has also been used as a structural material.
The proportion of composite materials in every new generation of aircraft developed by Boeing is increasing, with the highest proportion of composite materials in the Boeing 787 Dreamliner exceeding 50%. The main structural components of the Boeing 787 Dreamliner are made of more carbon fiber "sandwich" composite materials and advanced carbon fiber laminates, thus eliminating the outdated glass fiber composite materials.
On the other hand, aramid fibers are widely used in the construction of leading and trailing edge wing components, as well as very hard and lightweight bulkheads, fuel tanks, and floors. In addition, advanced composite materials composed of high-strength rigid fibers embedded in ordinary matrix materials are widely used in the aerospace industry.
1. CFRP as a structural material for aircraft
CFRP is widely used as the main load-bearing structural material in large advanced aircraft. And in the recently developed new airships, CFRP has also been used as a structural material.
The proportion of composite materials in every new generation of aircraft developed by Boeing is increasing, with the highest proportion of composite materials in the Boeing 787 Dreamliner exceeding 50%. The main structural components of the Boeing 787 Dreamliner are made of more carbon fiber "sandwich" composite materials and advanced carbon fiber laminates, thus eliminating the outdated glass fiber composite materials.
On August 17, 2016, a large airship developed by the UK completed its maiden voyage. This airship is a lighter than air spacecraft designed to perform reconnaissance, surveillance, communication, transportation of cargo and rescue supplies, as well as passenger transportation. The airship uses polyester fabric as the skin, which is filled with pressurized helium gas; The shape and structural material of the airship are made of CFRP, which maximizes the reduction of its own weight. Under unmanned conditions, the airship can float in the air for up to 5 days at a time.
2. CFRP as an advanced ship hull structure
CFRP has a significant impact on improving the structure, energy consumption, and maneuverability of ships.
Sweden has a traditional advantage in shipbuilding technology, with its sandwich composite material technology ranking among the world's top. It adopted CFRP technology to develop military ships earlier. The Swedish Navy frigate launched in June 2000 was the world's first naval vessel to use CFRP in its hull structure. The captain is 73.0m, the width is 10.4m, the draft is 2.4m, and the displacement is 600t; The hull adopts a CFRP sandwich structure, which has excellent properties such as high strength, high hardness, low mass, impact resistance, low radar and magnetic field signals, and absorption of electromagnetic waves.
Application of CFRP in Ship Hull Structure
Due to cost reasons, although the extensive use of CFRP in ships still needs some time, it has been actually used to manufacture key components for civilian new concept boats and military ships. In 2010, German company Kockums manufactured a new concept solar exploration vessel that was almost entirely made of CFRP. The ship is 31.0m long and 15.0m wide, powered by solar energy. On September 27, 2010, Swedish explorers set sail on the ship and began a global exploration voyage.
Application of CFRP in New Concept Boats
CFRP has also been used in the manufacturing of ship propulsion blades, integrated masts, and advanced surface ship superstructures.
Low noise and quiet operation are core technologies in the field of military ships, and are key indicators of ship (especially submarine) performance. Because when the propeller is running at high speed, intermittent air bubbles are generated on the propeller blades, causing blade erosion and accompanied by strong vibration and noise. CFRP blades are not only lighter and thinner, but also improve cavitation performance, reduce vibration and underwater characteristics, and decrease fuel consumption.
3. In the field of automotive industry
As the largest terminal application market for composite materials, the automotive industry is not unfamiliar with composite materials. In addition to pioneering vehicle design, composite materials also help make vehicles lighter and more fuel-efficient. Automobiles require reliable and synchronized mechanisms whose components can withstand friction, corrosion, and temperature fluctuations.
Inaccuracies in design or production will affect performance and may result in business losses for manufacturers. Compared with metal steel, the performance of composite materials can meet and exceed the needs of the automotive industry.
These unique features include:
Low thermal expansion coefficient
Excellent dimensional stability, able to maintain shape and reliability
Corrosion resistance under wet and dry conditions
High impact strength, capable of withstanding repeated use
Relatively lightweight to reduce the overall weight of the vehicle
Better sound insulation effect and performance
Acceptability of paint, including the ability to meet Class A surface requirements, paint and baking processes
Easy to manufacture, relatively low cost
Up to now, composite materials have been widely used in a range of automotive structural components, from the headlamp housing of the front headlight to the electrical and thermal insulation components under the engine hood, as well as exterior parts, internal structures, and decorative components of the car body. The following are common applications of composite materials in automotive components:
Deflectors and spoilers
Intake manifold
Battery casing and cover
Bumper and bumper crossbeam
Cylinder head (such as valve, rocker arm, cam) cover
Window/Sunroof Frame
Front grille opening plate
The housing of the front headlight
Insulation board (such as engine, transmission)
Pillars and coverings
Automotive and Motorcycle Accessories
4. Construction field
The construction industry is experiencing significant growth in its understanding and use of composite materials. Composite materials provide architects and designers with high performance and value in large-scale projects, and their use in commercial and residential buildings is increasing.
In the field of architecture, the high-strength properties of carbon fiber are playing a positive role. Carbon fiber has extremely high strength, is soft and easy to lay, and can be used to repair and reinforce buildings, making them look like brand new buildings. Carbon fiber laminates are widely used to improve the load-bearing capacity of floor slabs and columns. In addition, carbon fiber can resist earthquake damage, so it can also be used for structural reinforcement of new buildings and as a substitute for prefabricated steel bars.
CFRP for Building Reinforcement
5. CFRP as a reinforcement structure for wind turbine blades
Wind energy is the most cost-effective renewable energy source, and wind power generation has achieved rapid development in the past decade.
To improve the wind energy conversion efficiency of wind turbines, increasing the unit capacity and reducing the unit kilowatt weight are key factors. In the early 1990s, the single unit capacity of wind turbines was only 500kW, but now, offshore wind turbines with a single unit capacity of 10MW have been commercialized. Wind turbine blades are key components for effectively capturing wind energy in wind turbines, and the length of the blades continues to increase with the increase of the single unit capacity of wind turbines. According to the top rotation theory, in order to achieve greater power generation capacity, wind turbines need to be equipped with larger blades. Due to the issue of blade length, there is controversy in the industry about whether to develop wind turbines with a capacity of 10MW or above, but the mainstream view is that they need to be developed. Relevant personnel believe that the scientific law of the relationship between area and volume will ultimately limit the continuous growth of impeller diameter, but it has not yet reached its limit. Manufacturing a 10MW wind turbine is technically feasible; From the perspective of operational efficiency, reducing the operating cost per megawatt hour requires increasing the capacity of wind turbines.
The increase in impeller diameter imposes lighter and higher requirements on the quality and tensile strength of the blades. CFRP is a key material for manufacturing large blades, which can compensate for the performance deficiencies of glass fiber reinforced polymer (GFRP) composites. However, for a long time, due to cost factors, CFRP has only been used in key parts such as beam caps, blade roots, blade tips, and skins in blade manufacturing. In recent years, with the price of carbon fiber stabilizing and decreasing, coupled with further lengthening of blade length, the application areas of CFRP have increased, and the usage has also significantly increased. In 2014, the longest 6 MW wind turbine blade in China was successfully developed, with a total length of 77.7m and a mass of 28t. The main beam is made of 5t domestically produced CFRP. If GFRP design is adopted, the mass of the blade will reach approximately 36 tons.
6. Energy storage field
Multi functional energy storage composite materials (MESC) improve mechanical performance by embedding battery layers into the structure and fixing them with interlocking rivets. Experimental tests have shown that MESC can exhibit electrochemical behavior comparable to other materials. Compared with soft pack batteries, MESC achieves 15 times higher mechanical stiffness at a packaging efficiency of 60%.
Other representative applications of composite materials in the field of energy storage include:
Hydrogen tanks for aerospace use
Hydrogen fuel cell system
Natural composite material battery
7. Marine field
For decades, FRP composite materials have been successfully used in marine applications such as radar covers and mass structures, super yachts, workboats, and recreational boats. Recently, FRP has been used in less well-known applications such as bearings, propellers, commercial hatch covers, exhaust systems, and roof structures.
The use of glass fiber composite materials in marine applications is one of the first important areas of GRP application. It completely changes the ability to design and manufacture large composite structures in multiple fields. Ships are manufactured in the UK through various processes, including hand laid GRP, resin infusion, thermoplastic, and high-performance carbon fiber prepreg for racing yachts.
The main advantages of GRP in ship applications are:
Environmental resistance, including resistance to decay, corrosion, etc.
Capable of processing seamless and complex shaped structures
Ability to adjust intensity to adapt to load conditions
Excellent strength and weight characteristics - The weight of GRP marine structures is usually half that of equivalent steel structures.
Low maintenance and easy to repair
Excellent durability
Rowing boats use composite materials more widely than any other marine structure. Due to special requirements, the materials used are not typical marine building materials. The minimum weight and maximum stiffness are crucial in its design to be able to navigate at maximum speed and resist the effects of waves and other factors in the marine environment.
Carbon fiber reinforced epoxy resin composites are usually used for hull, frame, keel, mast, pole and suspender, carbon winch drum and shafting with honeycomb or foam as the core. Under different international navigation conditions, the use of FRP helps to improve performance and minimize the risk of navigation defects and malfunctions.
8. Pipeline system field
The application of composite material pipeline systems in chemical plants has exceeded 25 years. In the 1970s, the use of composite materials in industrial applications became widespread. Nowadays, the installation of composite material pipelines and storage tanks is on the rise in both above ground and underground, commercial, municipal, and residential applications. With the development of new chemical facilities and the expansion of old facilities, low-cost natural gas is further expanding its market.
Typical applications and products of composite material pipelines include:
Air pollution control
Aquaculture
Chemical processing
Seawater desalination
Oil and gas
Water and wastewater treatment
The Conduit
Pipe fittings and lining
Pipeline system
Fuel tank lining
Storage tank
Process container
Washing machine
valve
9. Sports and leisure field
Carbon fiber has always been outstanding in the field of sports equipment, with wide applications ranging from racing to skiing, golf, fishing, and tennis. With the increasing popularity and price drop of carbon fiber, it has been widely used in sports equipment.
Nowadays, many rackets, skis, sleds, hockey sticks, fishing rods, golf clubs, bicycles, surfboards, kites, shoes, and other sports products use carbon fiber.
CFRP in Sports Equipment
Currently, among the 10 most popular outdoor sports and leisure activities, 7 products use composite materials. Fiberglass and carbon fiber reinforced composite materials continue to replace wood and metal in fishing rods, tennis rackets, kayak paddles' wing beams/shafts, windsurfing masts and boards, hockey sticks, kites, and bicycle handlebars.
