KR20100122166A - Soft-ground arresting system for aircraft and simulation method for testing of such soft-ground arresting system - Google Patents

Abstract

According to the present invention, a pavement braking material of a passive aircraft which prevents the aircraft from leaving the runway safety zone by breaking the pavement itself when the aircraft installed in the runway safety zone of the airport, etc., travels upwards, and tests related thereto A method and analysis model for computer analysis.

Description

Soft-Ground Arresting System for Aircraft and Simulation Method for Testing of such Soft-Ground Arresting System}

The present invention relates to a method and an analysis model for testing a braking pavement of the aircraft and related braking pavement, and more particularly, the aircraft that is installed in the runway safety zone or landing zone of the airport to run to the top due to oversight or departure. The present invention relates to a braking pavement of an aircraft, which is then crushed by itself so that the aircraft does not leave the runway, and a method and analysis model for computer analysis of the related tests.

The runway at the airport is a very important facility for takeoff and landing of the plane. In general, landing aircraft should be safely stopped on the runway. According to statistics, over 10 plane runway accidents in Korea and abroad averaging expensive aircraft damages and valuable casualties.

In particular, most runways were built before the current runway safety zone (R.S.A) standards were established and were not in compliance with the facility standards. At the same time, ICAO and FAA have established a standard runway safety zone (R.S.A) of 300m (1,000 feet) in preparation for an overload accident, and the Korean Aviation Law also recommends 300m as a runway safety zone in case of an overrun accident.

However, if the standard safety zone is expanded, it is difficult to secure an extended space due to natural obstacles, environment, and regional development. Therefore, it is difficult to secure extended space due to the topographical, environmental, and economic impacts. The need for development is increasing.

In Korea, as the best member of the ICAO safety assessment, it is necessary to continuously develop an aviation safety system that meets international standards. In Korea, however, the aircraft's dynamic braking system is used only when the fighter lands on the airfield airfield and the deck of the aircraft carrier. The above-mentioned aircraft brake system installs steel wire on the runway, and when the arresting hook at the end of the aircraft is caught by the steel wire, it compresses the hydraulic cylinder connected to the steel wire and absorbs the forward movement of the aircraft to perform huge braking. It consists of hanging methods. However, such a rapid braking system is an aircraft emergency braking system for military use, and generally cannot be easily applied to civilian aircraft. In particular, the installation of hook assemblies in existing commercial aircraft requires a number of structural modifications.

In addition, the rapid braking device using the arrest wire (Arrest Wire), which is used for military use, can be used only on the aircraft carrier deck or air force aerodrome, and due to the rapid deceleration has a tremendous impact on the fighter pilot. Therefore, there are devices in the fighter to absorb shocks. If civil aircrafts use these arresting wire braking systems, they can have a detrimental impact on protecting passengers, crew and aircraft.

For this reason, countries around the world are actively researching rapid braking systems that can be applied to civilian aircraft. For example, in the United States, on February 28, 1984, a study was undertaken on the case of accidents caused by aircraft overcharging at JFK International Airport, and a study was started to develop a safe region of injury. Horne's research). The most probable of all types of overrunning types is the "Coverage Overlapping with Plastic Foam" and "Passive Foam Braking" through studies of the JFK Airport runway bed 4R / 22L (Cook.1988). It was concluded that the technical feasibility of the facility includes what has been properly described to ensure a high likelihood of success.

In addition, the Federal Aviation Administration (FAA) studied phenolic foam materials at New York and New Jersey airport complexes, and conducted a full-scale Boeing 727 aircraft in 1993 with Foamcrete. In addition to the establishment of oversized roads at the JFK International Airport in New York in 1996, it has been installed in 45 oversized roads at 30 airports in the United States.

In the case of the United Kingdom, the Royal Braking System was used to study braking facilities based on weak ground materials from 1960 to 1970.In 1974, Royal Aircraft Establishment (RAE) developed urea formaldehyde foam materials. A full-scale field trial was conducted at the Kai Tak Airport in Hong Kong on a Comet 38 aircraft.

However, full-scale research has not been conducted in Korea until now, and it is urgent to propose an efficient aircraft braking system suitable for Korea.

The present invention has been developed by the above needs.

Specifically, an object of the present invention is to propose an invention that can protect passengers and prevent expensive aircraft damage due to overdose accidents.

In the present invention, to provide an aircraft emergency braking facility through a domestic technology that is superior to the conventional technology and to secure the necessary technical force is a fundamental object.

In particular, it is an object of the present invention to secure competitiveness through the development of economical packaging materials, to design a rapid braking packaging facility, construction, development of maintenance standards and to exhibit improved performance than existing braking facilities.

Specifically, an object of the present invention is to provide a sudden braking packaging material in which the aircraft stops itself due to breakage of the pavement due to the aircraft load leaving the runway at the end of the runway and due to overcharging.

In addition, an object of the present invention is to provide a broken braking packaging material that can protect passengers due to overdose accidents and prevent damage to expensive aircraft.

In addition, the present invention is to provide a way to secure the technological power, secure the competitiveness through the development of economical packaging materials and export and commercialize overseas by developing the aircraft braking system with domestic technology.

According to the present invention, there is provided a sudden braking packing material in which an aircraft stops itself by breaking the pavement due to an electrodeposition on the end of the runway and an aircraft load that is over-exposed.

In addition, the present invention provides a computer simulation method that can easily confirm the behavior and effects of the rapid braking packaging material on the basis of the results from the actual simulation test using the rapid braking packaging material.

According to the present invention, it is possible to overcome the limitations of the conventional aircraft sudden braking packaging material, and to effectively prevent passenger damage and expensive aircraft damage due to overdose accidents. In addition, according to the present invention, it is possible to exhibit improved performance than the rapid braking facility design, construction, maintenance standards development and existing braking facility.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The present invention has been described with reference to the embodiments shown in the drawings, which are described as one embodiment by which the technical spirit of the present invention and its core configuration and operation are not limited.

First of all, when looking at the characteristics required by the braking pavement material of the aircraft, basically, the braking pavement material should be made of a material that can break the wheel to ensure that the material is broken by the load of the aircraft off the runway. It is also desirable to have a low density and a low compressive strength to be suitable for transport. It must also be resistant to vapor and chemical reactions. In addition, it should be a material that does not attract birds, pests and wildlife, and should be fireproof and waterproof.

First of all, lightweight foamed concrete can be considered as a rapid braking packaging material. FIG. 1 is a schematic perspective view of a braking packaging material manufactured using lightweight foam concrete. The rapid braking packaging material using lightweight foam concrete is concrete which is light weighted by artificially dispersing a large amount of bubbles in cement slurry by foaming agent without using lightweight aggregate, which can be manufactured in the form of foam bed as shown in FIG. have. Specifically, the lightweight foam concrete can be made of cement, foaming agent, water, and waterproof coating, which has the advantage of easy operation due to its low weight as a braking packaging material.

Another rapid braking packaging material is to produce a waterproof panel (panel) so as not to change the characteristics of the aggregates by the gas phase action, it is produced in the form of a thick bed or lightweight aggregate in the form of foam bed. 2 shows a schematic perspective view of such a braking packaging material. Specifically, in FIG. 2, the waterproof panel is made of cement, foaming agent, water and waterproof coating, and the filling material filled therein is made of lightweight aggregate (ceramic aggregate). The shortcomings of the braking characteristics of aggregates changed according to climatic conditions are complemented by waterproof panels, and the manufacturing and installation costs are low. On the other hand, particle size rearrangement, such as compaction of aggregates, may occur.

Next, the braking packaging material that can be considered is lightweight foam concrete. This is to make a lightweight aggregate concrete foam bed by mixing styrofoam bead or urethane foam, and then to form bubbles (voids) by melting the styro foam grains by the high temperature heated during steam curing. Use the method of production. 3 shows a schematic perspective view of such a braking brake packaging material. Specifically shown in Figure 3, consisting of cement, styrofoam beads, lightweight aggregate, water and waterproof coating, and includes EPS (Expanded Poly-Stylen) beads or foamed synthetic resin chips. It has an improved structural characteristic, has excellent compressive force in the uniaxial direction, and does not generate a clear shear zone. When a suitable amount of Styrofoam beads are mixed, the tensile strength is increased, and the installation cost is moderate.

Another braking packaging material is a porous ceramic panel (panel). It is manufactured by forming foam at high temperature by adding foaming agent to ceramic and then waterproof coating to form foam bed. 4 is a schematic perspective view of such a braking packaging material. Specifically, it is made of earth and sand, foaming agent, water and waterproof coating, and has the advantage of being brittle and flammable, low specific gravity, and capable of producing desired strength as a ceramic, and does not contain cement and is environmentally friendly.

Looking at the artificial light weight aggregate and the method of manufacturing such artificial light weight aggregates can be used in the braking braking packaging material in connection with the present invention, first, by mixing the quartzite products, fly ash, dolomite mine by-products, limestone powder, feldspar powder and water glass The mixture is shaped into spheres. An aqueous slurry of inorganic powder was applied to the surface of the spherical shaped body to form a film, followed by drying. The spherical shaped body was calcined, maintained at elevated temperature for 0 to 30 minutes, cooled to about 600 ° C., and then naturally cooled. do.

 There is also a method of producing light ash aggregates by the autothermal firing method, which can reduce the manufacturing cost and lower the cost of manufacturing than other types of firing processes such as DL type kilns by treating a large amount of ash with the development of autothermal firing technology using a shaft furnace that can mass-produce. In addition, it can contribute to the recycling of wastes by preventing environmental pollution and replacing natural aggregates. The results of the plasticity test using the shaft type furnace to manufacture the structural lightweight aggregate using coal ash are as follows.

Bentonite 10% was added to prepare a 5-18 mm diameter pellet having a drop strength of 2.5 or more. Light-weight aggregate production using Shaft-type kiln, firing conditions, when the raw ash is used as raw materials, the combustion air flow rate 14N ㎥ / hr, 12K ℃ discharge rate 50Kg / while maintaining the heating zone and the firing zone at 800 ℃ and 600 ℃ h, a light aggregate of 70 or more in collapse strength and 1.4 in dry weight was produced. Pellets were prepared by mixing bentonite 10% with coking ash from Boryeong thermal power plant as a caking agent, and it was possible to manufacture lightweight aggregate by autothermal firing using unburned carbon as a heat source through an integrated process such as firing.

On the other hand, expanded glass fine particles can be produced using recycled glass, and the pretreated and pulverized glass is finely ground, mixed and molded, and then the raw material particles are manufactured by firing in a kiln at a temperature of 750 ° C to 900 ° C. Done. Products manufactured through this process are ecologically trouble-free products derived from pure natural minerals, and are produced through environmentally friendly processes.

In particular, it contains no harmful substances, much lighter than water, nonflammability, cold / hot insulation, excellent hardness and durability, strong acid and steel corrosion resistance, strong resistance to organic solvents, pure minerals, excellent compression resistance, and resource recycling. Have Small air holes are formed through the foaming process. In addition, it is much lighter than water, and has the characteristics of having a thermal barrier performance of high compressive strength and high efficiency. FIG. 5 discloses a size-specific photograph of such expanded glass particles.

On the other hand, foamed glass is glass in which a uniform cell was formed in glass, and can provide a heat insulation and sound absorption characteristic according to the form of a cell.

Therefore, it is a heat insulator which gives porosity characteristics to the advantages of the glass itself, and has no feature of excellent heat insulation effect at cryogenic temperatures.

In addition, since it does not burn at high temperatures as well as cryogenic temperatures, it can be used in the field of building insulation because there is no risk of toxic gases in case of fire when used as a building insulation.

As a characteristic of foamed glass, water resistance is mentioned first. Water and water vapor are the main causes of failure of insulation. Foamed glass is impervious to water and water vapor. In addition, the foamed glass has non-corrosiveness and acid resistance. That is, it is safe from water and acid, and thus can maintain its function and shape in the long term without causing corrosion. Foam glass also has high compressive strength. Therefore, the shape and thickness are maintained even at high pressure and weight, and a stable thermal insulation effect is guaranteed. Foamed glass also has excellent fire stability. That is, because it is nonflammable, there is no toxic gas generation in case of fire. In addition, the foam glass is antibacterial and safe from mold, viruses, mice and pests. In addition, foam glass is environmentally friendly. It is eco-friendly because waste glass is recycled without generating CFC, Fiber, HFCF. In addition, the foam glass can be recycled semi-permanently, can be cut with a regular saw, and can be constructed with an adhesive, making it easy to install, and its excellent durability allows it to be used semi-permanently (more than 20 years) without any additional maintenance and low maintenance costs Do.

On the other hand, the borosilicate foam glass has the following characteristics. First, a block made of borosilicate foam glass (borosilicate foam glass block) is a material obtained by foaming a glass containing B₂O₃ in the raw material glass, and the glass containing B₂O₃ has strong chemical bonds in the glass, so its beaker glass, It can be used as an acid resistant container such as dish glass. Since raw material glass is made of glass having good acid resistance, foamed glass has excellent acid resistance. The use of borosilicate foam glass blocks in the lining system has the following advantages:

First, the borosilicate foam glass block is impermeable and does not penetrate sulfur dioxide and does not react with sulfur dioxide so there is no corrosion of the block.

Second, since the thermal conductivity of the glass block is much lower than other materials because it is filled with an adhesive of elastic material between the blocks, it can be used where the temperature change is severe.

Third, the lining system using borosilicate foam glass block increases the exhaust velocity of the exhaust gas by acting as a heat insulating material to maintain the combustion exhaust gas temperature in the stack structure. However, in case of using coating material or FRP (Fiber Reinforced Plastic) Liner, additional insulation should be added to the outside of the communication to vent the ventilator output, and the diameter of the communication can be reduced.

Fourth, in case of breakdown of air-heater, coating material or FRP communication is completely damaged by high temperature, while foamed glass liner is not damaged. Of course, an emergency quenching system can be installed in the coating liner or FRP communication, but this additional cost is not necessary for the borosilicate foam glass lining system. Table 1 below summarizes exemplary characteristics of the borosilicate foam glass block.

Next, in the present invention, lightweight foamed concrete will be described.

Lightweight concrete is concrete manufactured for the purpose of improving the shortcomings of concrete and at the same time giving excellent composite performance.The Korean Institute of Building Construction has a standard unit weight of 2.0 t / ㎥ in the standard construction standard 5.15.1. The following concrete is defined as lightweight concrete. The concrete specification stipulates that the design reference strength falls within the range of 240 kgf / cm 2 and the existing unit volume weight of 1.4 to 2.0 t / m 3.

The research on lightweight concrete has already been performed in developed countries since the late 19th century and has achieved a considerable level of performance. Various types of lightweight concrete have been manufactured and used. Lightweight concrete is largely divided into structural and non-structural applications, but is widely used in Korea. However, in Korea, lightweight concrete for structural use is due to the direct effect of reduction of its own weight due to lack of structural lightweight aggregate, immaturity of lightweight concrete mix design, and lack of recognition of lightweight concrete. Rather than being used as a non-concrete concrete for indirect effects such as insulation, soundproofing and waterproofing, and deck plate flooring materials.

Lightweight foamed concrete may refer to such lightweight concrete in a broad sense, but now it refers to lightweight concrete in which air bubbles generated by using a surfactant are mixed with cement and other additives.

Lightweight concrete is generally lightweight lightweight concrete that uses porous lightweight aggregates according to the method of lightweighting concrete, lightweight foamed concrete that reduces the weight by mixing bubbles generated in cement paste, and so that voids are formed between the aggregates as much as possible. It is classified as non-aggregate concrete that does not use fine aggregate. 6 is a schematic view showing the configuration state of each type of lightweight foam concrete. In Figure 6 from left to right is Muzan aggregate concrete, lightweight aggregate concrete, lightweight foam concrete is shown.

Table 2 below summarizes the types of lightweight concrete.

Specifically, looking at each concrete in detail, the aggregate-free concrete is concrete made of coarse aggregate and cement, water of 10-20 mm without the fine aggregate. In general, concrete is composed of two kinds of coarse aggregate and mortar. Muzan aggregate concrete forms concrete only with coarse aggregate coated with cement paste by excluding sand, which serves as a filler.

Therefore, a large amount of large voids are formed inside the ashless aggregate concrete. Since the voids greatly affect the physical properties of the ashless aggregate concrete, the compressive strength of the ashless aggregate concrete is lower than that of ordinary concrete, such as 50 to 150 kgf / ㎠. In addition, the unit volume weight is usually about 1.5 to 2.0 t / ㎥, and when using lightweight aggregates, specific gravity can be up to 0.64 t / ㎥, which saves the amount of unit cement in the formulation, and thermal properties, shrinkage rate, and workability are common in concrete. It is superior and its use is relatively diverse.

Lightweight foamed concrete is lightweight concrete that is light weighted by dispersing numerous independent bubbles in concrete with foaming agent without using lightweight aggregate, and has light weight, heat insulation, fire resistance and durability. According to the foaming method, they are classified as follows. Table 3 summarizes the types of foamed concrete.

end. Pre-Foaming Type

As a method of foaming the surfactant and the like with compressed air in advance and mixing the cement slurry, it is easy to control the amount of bubbles and easy to foam on-site.

I. After-Foaming Type

Metal powder premixed with cement is also called ALC (Autoclaved Light-weight Concrete) as a method of obtaining foaming by a gas generated through a chemical reaction.

All. Mixed-Foaming Type

Method of adding a surfactant to the cement slurry to foam in the mixing process.

la. Lightweight aggregate concrete

It is a concrete made from natural and artificial lightweight aggregates, and its history is known to have been used before the Roman Empire. The used lightweight aggregates are volcanic pumice of Greece and Italy. Remains.

In the present invention, the material test in the laboratory and the actual packaging waterproof test is performed through the following process.

end. Material test (lab operation)

-Characterization of lightweight aggregate: specific gravity, particle size, unit weight, wear test of aggregate.

-Strength Analysis of Brake Paving Materials: Compressive Strength Test (2.0 ~ 10.0kgf / cm ² ), Flexural Strength Test.

-Water content change of the braking packaging materials: dry density, wet density, unit weight test, and permeability test.

-Various tests necessary for hydration heat test.

I. Packing material waterproof test

Because of the large number of bubbles inside the concrete of the foam bed can not guarantee the cracking performance when the rain penetrates, the durability must be reduced, so waterproof is essential. Specifically, waterproofing sheet, waterproofing film, and penetration should be made.

In addition, the present invention provides a computer analysis method and a computer analysis model for the emergency braking packaging of the aircraft.

In the computer analysis method and computer analysis model according to the present invention, the characteristics of the aircraft which can be input variables are as follows.

-Aircraft Main Gear Type Aircraft Main Gear Type

-Clearance between the ground and the aircraft engine

-Working pressure of aircraft gear

-Tire width and height of the aircraft

-Gross Weight: Maximum Takeoff Weight, Maximum Landing Weight

Center of Gravity (%): mean aerodynamic pres- sure

-Fraction of total rev thrust

-Aircraft drop off speed at runway end: 30 knots-70 knots

-Friction coefficient of nose gear and main gear of free rolling (μ)

-Brake factor (μ)

On the other hand, in the computer analysis method and computer analysis model according to the present invention, the properties of the foam material which can be an input variable are as follows.

-Type of foam material Type of foam material

The density of the foam material, unit weight.

-Compressive strength, modulus of elasticity of foam material

Bed height

Rebound of form

The physical quantities obtainable through the computer analysis method and computer analysis model according to the present invention are as follows.

-Stopping Distance

Vertical Wheel Loads

-Drag Wheel Loads

Gear Height

-Rutting Depth: The depth dug by the wheel

In the computer analysis method and computer analysis model according to the present invention, the following matters may be considered.

-Relationship between braking distance and foam bed density

-Section height of the brake bed and the stopping distance from the end of the runway

-Stopping distance as a design function of the braking bed

7 and 8 are schematic diagrams for explaining the interface model of the wheel and the brake packaging material.

On the other hand, in the present invention, the simulation driving test is carried out, specific details related to the test are as follows.

end. Matters related to the location and location of the test

-Lung aerodrome use: Lung aerodrome is used in consultation with related organizations.

-Select a location where the construction vehicle is easily accessible.

-Consider future testbed recycling and availability.

-A short distance from the laboratory is preferred.

-Consider where electrical and other supply facilities can be drawn in.

-Measures for disposal of broken packaging materials after completion of the test.

I. Matters concerning the size and shape of the test bed

-Test width width: 10m

-Extension of Test Package: 50m

 All. Matters related to the measurement method

20 ~ 40 Knot (35 ~ 70km / hr)

-Measuring by changing the tire pressure of the airplane

-Measurement of packaging material behavior by strength and packing thickness

Specific matters related to the analysis of the simulation driving test results in the present invention are as follows.

end. Validation of Analysis Model

-Comparative analysis of simulation results and driving test results

-Resimulation after modifying variables

-Analysis of exit speed and packaging behavior

I. Material Characteristics by Strength by Thickness

-Analysis of Packing Material Behavior by Packing Thickness

-Analysis of Pavement Behavior by Strength of Pavement

All. Aircraft Braking Effect

-Braking distance analysis when using airplane reverse propulsion and brake

la. Aircraft wheel

-Analysis of Packaging Material Behavior According to Airplane Load

hemp. Rescue Fire Fighting Equipment Test

-Analysis of Pavement Behavior when Entering Rescue Vehicle

According to the present invention as described above, it is possible to set various standards, that is, design standards, construction standards, maintenance standards. In addition, according to the present invention, it is possible to obtain the results of the rapid braking packaging material developed by the domestic technology, it is possible to protect valuable lives from over-accident of the aircraft and to prevent damage to the aircraft.

In addition, as a member of the ICAO, Korea will be able to enhance its international status.

In particular, when applied to the end of the runway of the airport it is possible to prevent the arrival of the aircraft and the over injection path. Of course, the present invention can be utilized in a sudden braking pavement such as a general vehicle driving road in addition to the airport runway, it can also be used in a permeable packaging material and noise prevention panel technology.

1 is a schematic perspective view of a braking packaging material manufactured using lightweight foam concrete.

Figure 2 is a schematic perspective view of the braking packaging material produced in the form of a foam bed by putting a thick aggregate therein to produce a waterproof panel (panel).

Figure 3 is a schematic perspective view of the braking packaging material made of lightweight foam concrete.

4 is a schematic perspective view of a braking packaging material made of a porous ceramic panel (panel).

Figure 5 is a photograph showing the expanded glass particles by size.

Figure 6 is a schematic diagram showing the configuration state by type of lightweight foam concrete.

7 and 8 are schematic diagrams for explaining the interface model of the wheel and the brake packaging material.

Claims (1)

It consists of any one or combination of aggregateless concrete, lightweight aggregate concrete, lightweight foam concrete, lightweight aggregate and waterproof panel, lightweight foam concrete, porous ceramic panel, foam glass, and is installed in the safety zone or landing pad at the end of runway. A braking packaging material for an aircraft, characterized by causing the aircraft to stop by itself due to breakage of the pavement due to an overburden on the runway.

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