Mar 02,2018

The development of functional textiles is facing the problem of market recognition

A few days ago, at the "Exploration and Innovation-China's Functional Textile Technology Innovation and Application" seminar held in Beijing, Yang Shibin, President of the China Knitting Industry Association, pointed out in his keynote speech "Functional Textile Demand Status and Future Development Trends" In view of the strong supply capacity and strong market demand, functional textiles will continue to show a rising development momentum in my country. However, the whole industry is also facing a huge challenge, that is, how to make the products put on the market fully trusted by consumers. To solve this problem, production enterprises need to responsibly build the whole process industrial chain, including R & D, production, sales, etc., especially to publicize the product functions and characteristics to consumers. At the same time, with the help of standards and various testing means to ensure product safety and reliability.

Mar 02,2018

National Military Textile Standard Project Opening Topic

"The overall development of the industrial textile industry is at a relatively high level; the attention from the society to the government to the industry is gradually increasing; the industry progress represented by technological innovation and labor productivity improvement has become a development model; the industrial industry's 13th Five-Year Plan It has risen to the ranks of national key plans." Li Lingshen, president of the China Industrial Textiles Industry Association, pointed out in his industry situation analysis report that the proportion of industrial textiles in the industry will become larger and larger, and military textiles are an important part of it. On November 28, the fourth meeting of the first Council of the Special Textiles Branch of the China Industrial Textiles Industry Association and 2

Jul 11,2017

Military Textiles in the "Pretender" Various Materials Competition

Camouflage technology is a variety of technical measures taken to conceal oneself and deceive the enemy, and is an important means to ensure the combat effectiveness of the army. Stealth technology is a comprehensive technology that changes the detectable information characteristics of weapons and equipment and other targets, making it difficult for enemy detection systems to find them. Stealth technology is the improvement of camouflage technology. Modern camouflage technology is mainly to reduce the difference between the target and the background in visible light, laser, thermal infrared, electromagnetic waves and other aspects of the various technical interference measures taken. 1. Laser stealth technology Laser stealth is to make the target have lower detectability by reducing the reflection and scattering signal of the target to the laser, and the focus is to reduce the laser radar cross section LRCS and laser reflectivity of the target. Among them, LRCS comprehensively reflects the influence of various factors such as laser wavelength, target surface material and its roughness, target geometry and shape on the target laser scattering characteristics, and is the main index for characterizing the target laser scattering characteristics. There are two main types of laser stealth technology. Structure type: The structure is designed as an absorption type multilayer sandwich core, or the composite material is made into honeycomb, corrugated, laminated, tapered, etc. When the laser returns from the structure end, the special structure of the material can reduce the intensity of the reflected laser signal and prolong the arrival time of the reflected laser. Coating type: Reduce the reflection of the target on the laser. Laser stealth mainly refers to the stealth of 1.06, 1.54 and 10.6μm lasers, of which 1.06μm laser stealth is the most important, because the current working wavelength of laser-guided weapons is mainly 1.06 μm. If the coating can reduce the diffuse reflectance of laser light at these wavelengths, it will have a significant laser stealth effect. Laser stealth materials are mainly divided into two types: absorbing materials and nanomaterials. Absorbing materials are mainly used to absorb light waves irradiated on the target, and their absorption capacity depends on the permeability and dielectric constant of the material, and the absorption wavelength depends on the thickness of the material. Nanomaterials are materials with a characteristic size of 0.1 ~ 100nm, which have the characteristics of wave absorption, frequency bandwidth, good compatibility, small mass and thin thickness.

Jan 12,2023

Fault cause analysis

At present, the parachute of this type of aircraft is electrically controlled. When the aircraft lands, the pilot controls the parachute release button, the parachute release head of the parachute mechanism explodes, the parachute release piston extends, the parachute hatch opens, and the parachute release parachute is released. The parachute piston extends, the parachute lock hook opens, and the parachute is released from the lock hook. The analysis of the working mechanism of the resistance umbrella mechanism of this type of aircraft shows that there are two main reasons why the failure rate of the mechanism is high and the flight safety is directly endangered after the failure occurs: 1. The umbrella hook has no "false lock" state, and the resistance umbrella cannot be automatically thrown off after accidental release; 2. Using the explosive tube as the power source for releasing and throwing the umbrella not only has a large maintenance workload, but also has a large impact force in the working process, the piston rod of the small hydraulic cylinder causing the electric explosion tube becomes blunt and thick after impact, and some even deform, causing the piston to jam and reducing the working reliability of the resistance umbrella mechanism.

Jan 12,2023

How does the plane slow down during landing?

In general, thrusts, wheel brakes and spoilers can help the aircraft slow down when landing. A thrust reverser is a device that produces thrust in the direction opposite to the direction of flight of the airplane. During engine operation, a large amount of gas is ejected backward at high speed, generating thrust consistent with the flight direction of the aircraft, allowing the aircraft to overcome air resistance and fly forward. The thrust reverser bends the engine gas to the front of the engine, causing the gas to be ejected to the front of the engine, generating a force opposite to the forward direction of the aircraft, I .e., reverse thrust, which helps the aircraft to decelerate more quickly. The wheel brakes are the main deceleration device during aircraft landing and taxiing. When the driver operates the brake, the hydraulic oil enters the brake cylinder fixed on the axle, presses the brake pad, and presses the rotor and stator. As the friction increases the torque that prevents the wheels from rolling, the ground friction that the wheels receive during rolling increases significantly, and the sliding speed of the aircraft decreases. Spoilers can be divided into ground spoilers and flight spoilers according to their functions. The spoiler can only be used on the ground. When the aircraft lands, the ground spoiler can be fully released to remove the wing lift and improve the braking efficiency. The spoiler can be used in the air or on the ground. When used on the ground, it acts like a spoiler.

Jan 12,2023

What is the deceleration umbrella made of? Can withstand such a large pulling force

The ideal material for the main cable of the deceleration umbrella is super carbon fiber. According to the data, the strength of super-grade carbon fiber can reach 100 times that of ordinary steel, but the density is only 1/6 of that of steel. But even if this material can be put into practical use, its price is very expensive, not conducive to promotion. In addition, at present, the material used as the main cable of the deceleration umbrella is mainly high-strength and high-modulus polyethylene fiber. The tensile strength of this material is more than 10 times that of high-quality steel. The cable with a diameter of 1cm can bear 50 tons of pulling force, that is, 64 tons of pulling force per square centimeter. Furthermore, the lower end of the main cable of the deceleration umbrella is the most stressed and the upper end is the smallest. Therefore, the diameter of the lower end (the end connected to the aircraft) is generally 2cm, the diameter of the upper end (the end of the guide umbrella) is generally 1cm, and the average diameter is 1.5cm (the radius is 0.75cm). When making cables, the diameter of the cables is uniform and excessive from large to small. The cross-sectional area of the fixed end of the main cable is about 3.14 square centimeters, and the tensile force that can be borne is: 3.14*64 tons = 200 tons, so it can definitely meet the requirements of decelerating the aircraft. Finally, when it comes to the speed of the aircraft so fast, suddenly open the umbrella, will it be harmful to the fuselage, this is for sure! Therefore, under what circumstances (or only what conditions are available) can the umbrella be opened, which is strictly required. For example, the speed of the aircraft (this is the main factor, when the speed is high, opening the umbrella may cause the engine to stop suddenly, which is very dangerous. In addition, the sudden deceleration of the aircraft can also cause damage to the fuselage structure), so it is generally stipulated that the parachute can only be opened when the speed of the aircraft reaches below a certain value.

Jan 12,2023

The use and training method of resistance umbrella

A drag parachute, also called a parachute, is an umbrella-like tool used to reduce the speed of an aircraft when it lands. It is usually composed of a main umbrella, a guiding umbrella and an umbrella bag, etc., and is installed in an umbrella cabin at the tail of the aircraft. During the landing and running of the aircraft, the pilot operates to open the umbrella hatch. The guiding umbrella is first opened, the umbrella bag is pulled out, and the main umbrella is opened. After the umbrella coat is pulled out and opened, the air resistance can be increased, and the aircraft is dragged backward to slow down and shorten the running distance.

Jan 12,2023

Why open the parachute when the plane is landing

When landing, the landing distance can be reduced. It can also be said that the length of the runway required to land is longer to reduce the inertia of the aircraft. If it is forced to land on the island, it is necessary to open the parachute. There is also a 300-meter-long aircraft carrier that is not enough for the aircraft to land. The aircraft carrier is to pull the cable and land. The aircraft carrier also has a springboard for the aircraft to take off, which also reduces the required length.

Jan 12,2023

Resistance umbrella failure performance

The drag parachute system is an important part of the aircraft system and an important guarantee for the safe flight of the aircraft. The common faults of the resistance umbrella system are as follows: 1. The aircraft takes off and runs, automatically opens the umbrella during normal flight, and cannot throw off the resistance umbrella. The sudden increase in aircraft resistance causes the aircraft to lose control. The failure to automatically open the parachute during the take-off run and be forced to terminate the take-off occurs from time to time. 2. The plane will automatically throw the umbrella after putting the umbrella during landing and running. The pilot can only make the plane slow down gradually by/point brake 0. Due to the high speed of the aircraft landing and taxiing process, there is little room for the pilot to deal with it. If it is not found in time, it is difficult for the pilot to decelerate the aircraft to a safe speed through the brakes. It is easy to cause the tires to burst due to excessive braking or rush out of the runway, causing accident symptoms.

Jan 12,2023

Structure and working principle of resistance umbrella system

When installing the resistance umbrella, the umbrella hanging ring hits the umbrella lock hook, and the upper and lower lock hooks are closed under the action of the impact force (the upper and lower lock hooks are required to have a clearance of no more than 5mm). The piston pushes the slider into the umbrella lock under the action of the spring force to make the umbrella lock in the "false lock" state. At the same time, the piston moves to drive the rocker arm 1 to rotate clockwise. The rocker arm pulls the coordination cable 2, the bump on the unlocking rocker arm 7 is just abutted by the interlocking rocker arm 4 to ensure that the resistance umbrella lock will not rush through the false lock position due to inertia. After closing the door, the door lock 5 drives the interlocking rocker arm 4 through the connecting rod to disengage the unlocking rocker arm, and the stop rocker arm 6 rotates clockwise under the action of the friction force of the lock hook and the spring force to abut the lock hook of the door lock, so that the door can be locked reliably. When the airplane is landing and sliding, after the pilot presses the switch of "release umbrella", the cold air pushes the piston to make the slider fully extend into the lock hook of the umbrella. During the movement, the slider drives the rocker arm 1 to continue to rotate clockwise. The rocker arm pulls the coordination cable 2, the cable pulls the unlocking rocker arm 7, and the unlocking rocker arm 7 drives the stop rocker arm 6 to rotate counterclockwise to unlock the cabin door lock to ensure the umbrella successfully, at the same time, the slider continues to extend into the umbrella lock to make the upper and lower lock hooks of the umbrella lock closer (the gap between the upper and lower lock hooks is required to be no more than 1mm) to ensure that the umbrella lock is in the "true lock" state.