As cities around the world become smarter, how will infrastructure support smart city development? Experts explained how composite materials can help promote the development of smart cities. The public transportation system is a key element of a smart city. To optimize commuting, smart cities need sensors to accumulate and control large amounts of traffic data. Obviously, the response data infrastructure will be as important as today's power and water infrastructure. To support this infrastructure, composite materials will play a key role in providing uninterrupted data flow.
Composite materials offer great possibilities for protecting data infrastructure. Unlike metals that shield these signals, composite materials like fiberglass are transparent. This makes the composite material an ideal material that can continuously transmit data throughout the smart city.
Composite materials are new materials that people use advanced material preparation technology to optimize the combination of different properties of material components. Generally defined composite materials must meet the following conditions:
(i) The composite material must be man-made, a material designed and manufactured by people according to their needs;
(ii) The composite material must be composed of two or more material components with different chemical and physical properties in the designed form, ratio, and distribution, and there is a clear interface between each component;
(iii) It has structural designability and can be used for composite structure design;
(iv) Composite materials not only maintain the advantages of the performance of each component material, but also can obtain comprehensive performance that cannot be achieved by a single component material through the complementarity and correlation of the performance of each component.
The matrix materials of composite materials are divided into two categories: metal and non-metal. Metal substrates commonly used are aluminum, magnesium, copper, titanium and their alloys. Non-metallic substrates mainly include synthetic resin, rubber, ceramics, graphite, carbon, etc. Reinforcement materials mainly include glass fiber, carbon fiber, boron fiber, aramid fiber, silicon carbide fiber, asbestos fiber, whisker, metal.
Among the composite materials, fiber reinforced materials are the most widely used and the most used. It is characterized by small specific gravity, large specific strength and large specific modulus. For example, carbon fiber and epoxy resin composite materials have specific strength and specific modulus several times larger than steel and aluminum alloy, and also have excellent chemical stability, friction and wear resistance, self-lubrication, heat resistance, fatigue resistance, resistance Creep, noise reduction, electrical insulation and other properties. Graphite fiber combined with resin can get material with thermal expansion coefficient almost equal to zero. Another feature of fiber-reinforced materials is anisotropy, so the arrangement of fibers can be designed according to the strength requirements of different parts of the part. Aluminum matrix composites reinforced with carbon fiber and silicon carbide fiber can maintain sufficient strength and modulus at 500 ℃. Silicon carbide fiber is compounded with titanium, which not only improves the heat resistance of titanium, but also wear resistance, can be used as engine fan blades. Silicon carbide fiber and ceramic are compounded, and the service temperature can reach 1500 ℃, which is much higher than that of super alloy turbine blades (1100 ℃). Carbon fiber-reinforced carbon, graphite fiber-reinforced carbon, or graphite fiber-reinforced graphite constitute ablation-resistant materials and have been used in spacecraft, rocket missiles, and nuclear reactors. Due to the low density of non-metal matrix composite materials, it can be used in automobiles and aircraft to reduce weight, increase speed and save energy. The composite leaf spring made of carbon fiber and glass fiber has the same rigidity and load-bearing capacity as the steel leaf spring which is more than 5 times heavier.
5G has become another key driving force in the development of smart cities. Fiberglass antennas can be hidden in existing infrastructure such as light poles and traffic lights, making it easy for cities to integrate the technology. The light-weight, corrosion-resistant and wave-transmitting properties of composite materials help to promote data transmission in today's and future smart cities.
Infrastructure creates further obstacles to shortwave frequencies, which may cause 5G to hit the wall. Due to its ultra-low latency, the availability of 5G may be greatly reduced because its high frequencies may be difficult to penetrate buildings. Since 80% of the equipment is used inside the building, this loss or reduced availability will seriously affect the adoption of this technology.
However, incorporating fiberglass components into buildings (such as in door and window frames) will help reduce the weakening of signals entering our houses. In addition, because FRP can withstand strong ultraviolet rays, extreme temperature and humidity changes, composite parts also provide durable materials for smart city buildings, thereby reducing the overall life cycle cost.
In order to optimize public transportation, composite materials can provide a lightweight solution. Composite materials are used throughout the vehicle, which helps to save fuel, reduce pollution and reduce the maintenance cost of the vehicle life cycle.
Smart cities are no longer the future. Composite materials play an important role in the success of smart cities, and their series of advantages create durable solutions.