CN112066207B - Integrated support for large-mass low-scattering target RCS test and application thereof - Google Patents

Integrated support for large-mass low-scattering target RCS test and application thereof Download PDF

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Publication number
CN112066207B
CN112066207B CN202010959863.7A CN202010959863A CN112066207B CN 112066207 B CN112066207 B CN 112066207B CN 202010959863 A CN202010959863 A CN 202010959863A CN 112066207 B CN112066207 B CN 112066207B
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Prior art keywords
bracket
wood
transverse supporting
foam
integrated bracket
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CN202010959863.7A
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CN112066207A (en
Inventor
侯鑫
魏润萌
杨景轩
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Beijing Institute of Environmental Features
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Beijing Institute of Environmental Features
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16M—FRAMES, CASINGS OR BEDS OF ENGINES, MACHINES OR APPARATUS, NOT SPECIFIC TO ENGINES, MACHINES OR APPARATUS PROVIDED FOR ELSEWHERE; STANDS; SUPPORTS
    • F16M11/00—Stands or trestles as supports for apparatus or articles placed thereon Stands for scientific apparatus such as gravitational force meters
    • F16M11/20—Undercarriages with or without wheels
    • F16M11/24—Undercarriages with or without wheels changeable in height or length of legs, also for transport only, e.g. by means of tubes screwed into each other
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B9/00—Connections of rods or tubular parts to flat surfaces at an angle
    • F16B9/02—Detachable connections
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section

Abstract

The invention relates to an integrated bracket for RCS (radar cross section) testing of a large-mass low-scattering target and application thereof. The integrated bracket is made of wood with the following properties: the air-dried density is (100-250) kg/m3(ii) a Air-dry hardness is (400-; the water content is 8-15%; and a relative dielectric constant of not more than 1.05. The wood with specific properties (air dry density of (100-) -250) kg/m is adopted3(ii) a Air-dry hardness is (400-; the water content is 8-15%; and the relative dielectric constant is not more than 1.05), the bracket made of the wood has higher hardness and rigidity than a foam bracket, has higher dimensional stability than the foam bracket, has smaller stress deformation than the foam bracket, and is suitable for high-frequency RCS tests of Ku wave band, K wave band, Ka wave band and the like which are sensitive to fine deformation.

Description

Integrated support for large-mass low-scattering target RCS test and application thereof
Technical Field
The invention relates to the technical field of RCS testing, in particular to an integrated bracket for large-mass low-scattering target RCS testing and application thereof.
Background
The western developed countries represented by the united states and the asian neighbors represented by japan place high importance on the research and development of stealth technology, competition in the stealth field is increasingly intense, and new ideas of new technologies emerge endlessly. With the continuous development of stealth technology, the RCS (Radar cross-section) value of a target is lower and lower, the detection difficulty of the target is higher and higher, and the limitation of the bandwidth of a sensor brings great difficulty to anti-stealth. In order to clearly understand the electromagnetic scattering characteristics of different targets in various postures and in different electromagnetic environments, corresponding target electromagnetic scattering characteristic data are mastered, and then target scattering center distribution is obtained through analysis, so that the method has great significance for targeted anti-stealth design.
Because we do not have the real target of the foreign army, the real test data of the target of the foreign army can not be directly obtained, the test can be carried out only by using a scaling target model or a conceptual model made of information such as related stealth appearance and stealth means obtained according to a special channel to obtain related data, and the data closely related to detection and identification is the radar scattering sectional area.
RCS mainly includes indoor field test and external field test according to the size of the target, the indoor field is generally adopted when the size of the target is within 9m, and the external field test is adopted when the size of the target exceeds 9 m. During testing, in order to avoid the influence of ground clutter on the test, the target must be erected to a certain height through the support, the target RCS under different azimuth angles and pitch angles is obtained by simulating different postures of the target through the movement of the rotary table or the two-dimensional rotary top, so that the support is indispensable for RCS testing, and the stability, low scattering, reliability and safety of the support are very important for the accuracy of the RCS.
At present, a polystyrene foam bracket is mainly adopted in indoor field tests, and the polystyrene foam is widely applied to RCS tests due to low cost and easy production and acquisition. The foam section is processed into a low-scattering shape through mechanical processing or a thermal resistance wire, and a large size is obtained through bonding of different foam sections, so that a truncated cone-shaped foam support with a certain height and bearing capacity is finally formed. The foaming process fills the foam with air, the air content, blowing agent and foamed particle size determining the density, maximum foamable size and dielectric constant of the polyethylene foam. The mixed air reduces the density of the polystyrene foam, reduces the dielectric constant and the reflectivity of the foam material, but the foaming process needs to be formed by a mold, so that the large-scale foam foaming needs the mold with at least the same size, and the foam belongs to flammable materials, so that the production is dangerous, and the production cost of the mold is extremely high. Because the foam section bar cannot be made to be too large, the support for testing the large load-bearing target is basically spliced by the foam, however, the splicing is added with the adhesive, so that the scattering inside the foam is complex and difficult to control, and the testing background level is raised.
In summary, the conventional foam scaffold made of polystyrene has the following problems:
(1) due to the limitation of the foam production process and the consideration of safety, a flame retardant is doped in the production process to improve the flame retardance of the foam, the flame retardant is difficult to disperse uniformly in the foam, so that the foam is not consistent any more and generates the problem of anisotropy, the dispersed particles can scatter electromagnetic waves, and the nonuniformity in the foam can also cause the appearance of noise waves, thereby being not beneficial to low RCS test;
(2) in the foam forming process, countless bubbles are formed due to continuous generation and expansion of the bubbles, so that the volume and the surface area of a foam system are increased, the thickness of bubble walls is thinned, the foam system is unstable, and stable large-mass load bearing is difficult to realize by depending on the bonding force among foaming particles;
(3) the foam is formed by foaming foam particles, has certain flexibility, and can be extruded to deform or even crack when a large-load-bearing test is carried out. Background cancellation depends on the consistency of the conditions of a darkroom and a target in testing, and the change of the bracket causes the inconsistency of two states, so that the background cancellation effect is greatly reduced, even clutter is introduced to make the background stronger, and even dangerous accidents occur;
(4) due to insufficient foam rigidity, the processability of foam is poor, complex low-scattering shapes are difficult to process, the processing surface precision and the surface quality are difficult to control, a rough surface is easy to form, and the surface diffuse scattering of electromagnetic waves by the foam support is aggravated;
(5) the RCS test needs to be carried out by erecting a target at the central height of a dark room dead zone, single foam cannot meet the requirement and needs to be solved in a foam splicing mode, but due to the addition of the binder, material property mutation occurs at the foam bonding position, so that electromagnetic waves are reflected and scattered, the background level is raised, and the RCS test is not favorable for low RCS test.
Disclosure of Invention
The invention aims to provide an integrated bracket for RCS (radar cross section) testing of a large-mass low-scattering target, which solves the problems that the cancellation effect of a target background is poor and the influence of the bracket mixed in test data is large due to the segmentation and deformation of the bracket during the conventional large-mass target testing, so that the data error is large. The influence of the support body on the test is weakened to the maximum extent, and the coupling between the support and the tested target is reduced, so that the test data can reflect the real result to the maximum extent.
In order to achieve the purpose, the invention provides the following technical scheme:
an integrated bracket for RCS testing of large mass low scattering targets, the integrated bracket being made of wood having the following properties:
the air-dried density is (100-250) kg/m3；
Air-dry hardness is (400-;
the water content is 8-15%; and
the relative dielectric constant is not more than 1.05.
Preferably, the integrated bracket is formed by splicing the wood.
Preferably, the splicing method is mortise and tenon joint.
Preferably, the integrated bracket comprises a plurality of transverse supporting pieces and a plurality of longitudinal supporting pieces, and the transverse supporting pieces and the longitudinal supporting pieces are spliced into an integrated structure in a mortise-tenon connection manner;
the transverse supporting piece comprises a 1 st transverse supporting platform, a plurality of transverse supporting platforms and a plurality of transverse supporting platforms, wherein the diameters of the transverse supporting platforms are sequentially increased from top to bottom, and N is larger than or equal to 2.
Preferably, the number of the longitudinal supporters is 3 or more.
Preferably, the number of longitudinal supports is even.
Preferably, the included angle between the generatrix of the integrated bracket and the vertical line is 10-20 degrees.
Preferably, the number of the transverse supporting members is 3, and the value of N is 3.
Preferably, the wood is made of balsa wood.
The integrated bracket provided by the invention is applied to RCS tests of Ku wave bands, K wave bands or Ka wave bands of indoor and outdoor fields.
Advantageous effects
The technical scheme of the invention has the following advantages:
(1) the wood with specific properties (air dry density of (100-) -250) kg/m is adopted3(ii) a Air-dry hardness is (400-; the water content is 8-15%; and relative dielectric constant not greater than 1.05), the bracket made of the wood has higher hardness and rigidity than the foam bracket and higher dimensional stability than the foam bracket,the stress deformation is much smaller than that of a foam bracket, and the device is suitable for high-frequency RCS tests of Ku wave bands, K wave bands, Ka wave bands and the like which are sensitive to fine deformation.
(2) The integrated support provided by the invention adopts an integral design, adopts splicing of the sectional materials to realize a non-bonding design, and avoids the influence of a bonding agent on the test.
(3) The included angle between the bus and the vertical line of the integrated bracket provided by the invention is designed to be 10-20 degrees, and the design ensures that the bracket has better stability.
Drawings
FIG. 1 is a schematic perspective view of an integrated bracket for RCS testing of a large-mass low-scattering target according to an embodiment of the present invention;
FIG. 2 is a schematic view of an integrated bracket for RCS testing of a large-mass low-scattering target according to an embodiment of the present invention;
FIG. 3 is a schematic view of an integrated bracket for RCS testing of a large-mass low-scattering target according to an embodiment of the present invention;
FIG. 4 is an ISAR imaging view of a prior art foam stent;
fig. 5 is an ISAR imaging diagram of an integrated bracket provided by an embodiment of the present invention.
In the figure: 11: 1, a transverse supporting platform; 12: 2 nd transverse supporting platform; 13: a 3 rd transverse supporting platform; 21: a longitudinal support.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
The present invention provides in a first aspect an integrated bracket for RCS testing of large mass low scattering targets, the integrated bracket being made of wood having the following properties:
the air-dried density is (100-250) kg/m3；
Air-dry hardness is (400-;
the water content is 8-15%; and
the relative dielectric constant is not more than 1.05.
Compared with a foam bracket, the bracket made of the wood has higher hardness and rigidity, higher dimensional stability than the foam bracket, and smaller stress deformation than the foam bracket, and is suitable for high-frequency RCS tests sensitive to fine deformation in Ku wave band, K wave band, Ka wave band and the like.
When selecting the wood, the air-dried density, air-dried hardness, water content, or relative dielectric constant of the wood can be made to satisfy the above requirements by drying treatment or air-drying treatment.
The invention optimizes the support structure besides the manufacturing material. In some preferred embodiments, the integrated scaffold is formed by splicing the wood, and more preferably, the splicing method is a mortise and tenon joint (the prior art and the invention are not described in detail herein). The splicing of the sectional materials is adopted to realize the non-bonding design, so that the influence of the binder on the test is avoided.
In some preferred embodiments, the integrated bracket comprises a plurality of transverse supporting members and a plurality of longitudinal supporting members, and the transverse supporting members and the longitudinal supporting members are spliced into an integrated structure through a mortise-tenon connection manner;
the transverse supporting piece comprises a 1 st transverse supporting platform, a plurality of transverse supporting platforms and a plurality of transverse supporting platforms, wherein the diameters of the transverse supporting platforms are sequentially increased from top to bottom, and N is larger than or equal to 2.
In some preferred embodiments, the number of the longitudinal supports is 3 or more, and more preferably, the number of the longitudinal supports is an even number.
In some preferred embodiments, the generatrix of the integrated support is at an angle of 10 ° to 20 ° to the vertical. Such a design provides the stent with better stability.
In some preferred embodiments, the number of the lateral supports is 3, i.e. N has a value of 3.
In some preferred embodiments, the wood is balsa wood. The balsa is low-temperature-resistant lightweight wood, still has good mechanical properties and sufficient strength and hardness in a low-temperature environment, and can be used in indoor places and outdoor places.
The integrated bracket provided by the invention in the first aspect can be applied to RCS test of Ku wave band, K wave band or Ka wave band of indoor and outdoor fields.
The following are examples of the present invention.
The low-temperature-resistant light balsa wood is used as a raw material for processing the bracket, and the material still has good mechanical property, sufficient strength and hardness in a low-temperature environment, and can be used in indoor fields and outdoor fields.
Drying the wood, and requiring the air-dried density to be not more than 200kg/m after the treatment3Air-dry hardness is not less than 600JH Jansen hardness.
The dehumidifying and drying method is adopted to carry out air drying treatment on the wood, so that the relative dielectric constant of the wood is reduced, the relative dielectric constant of the wood is not more than 1.05, the cracking and deformation of the wood caused by uneven wet expansion and dry shrinkage of the wood are avoided, and the stability of the wood is improved.
The moisture content of the wood is controlled to be 8-15%, so that the strength and the corrosion resistance of the wood are improved, the weight of the wood is reduced by about 30-50%, and the wood is convenient to carry and transport.
As shown in fig. 1 to 3, the bracket includes 3 transverse supporting members and 6 longitudinal supporting members 21, and the transverse supporting members and the longitudinal supporting members 21 are spliced into an integral structure through a mortise-tenon connection manner;
the transverse supporting piece comprises a 1 st transverse supporting platform 11, a 2 nd transverse supporting platform 12 and a 3 rd transverse supporting platform 13, wherein the diameters of the transverse supporting platforms are sequentially increased from top to bottom. It should be noted that the three lateral support platforms are circular in shape.
6 vertical support piece 21 evenly distributed passes through mortise and tenon joint mode concatenation structure as an organic whole with the edge of above-mentioned three horizontal supporting platform, plays the effect of fixed above-mentioned three horizontal supporting platform.
The included angle between the bus of the integrated bracket and the vertical line is 15 degrees, and the design enables the bracket to have better stability.
Compared with a foam bracket, the wood bracket has higher hardness and rigidity, higher dimensional stability and smaller stress deformation than the foam bracket, and is suitable for RCS tests of Ku, K, Ka and the like of outdoor and indoor fields sensitive to fine deformation.
The large-mass low-scattering target RCS test integrated support adopts an integral design, a splicing-free design is realized by adopting the splicing of sectional materials, and the influence of a binder on the test is avoided.
ISAR imaging is carried out on the wood bracket provided by the embodiment and the existing foam bracket, and the overall electromagnetic scattering property of the bracket is comprehensively evaluated.
As is apparent from the comparison between fig. 4 and fig. 5, the imaging contour of the foam bracket ISAR imaging central target area is obvious, and a large amount of scattering exists, which indicates that the surface reflection of the foam and the air contributes to most of the scattering, and the ISAR imaging confusion inside the foam indicates that the clutter scattering is high; the imaging contour of the target area of the ISAR imaging center of the wooden support almost disappears, the interior is clean, the scattering of the wooden support is lower than that of the foam support by more than 30dB, and the design of the low-scattering support is realized.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (5)

1. An integrated bracket for RCS testing of a large-mass low-scattering target, characterized in that the integrated bracket is made of wood having the following properties:
the air-dried density is (100-250) kg/m3；
Air-dry hardness is (400-;
the water content is 8-15%; and
a relative dielectric constant of not more than 1.05;
the integrated bracket is formed by splicing the wood;
the splicing method is tenon-and-mortise connection;
the included angle between the bus of the integrated bracket and the vertical line is 10-20 degrees;
the wood is made of balsa wood;
the integrated bracket is in a round table shape and comprises a plurality of transverse supporting pieces and a plurality of longitudinal supporting pieces, and the transverse supporting pieces and the longitudinal supporting pieces are spliced into an integral structure in a mortise-tenon joint mode;
the transverse supporting piece comprises a No. 1 transverse supporting platform … … and an Nth transverse supporting platform, the diameters of the No. 1 transverse supporting platform and the Nth transverse supporting platform are sequentially increased from top to bottom, and N is larger than or equal to 2.
2. The integrated bracket of claim 1,
the number of the longitudinal supporting pieces is more than 3.
3. The integrated bracket of claim 2,
the number of longitudinal supports is even.
4. The integrated bracket of claim 1,
the number of the transverse supporting pieces is 3, and the value of N is 3.
5. Use of the integrated scaffold of any of claims 1 to 4 in the RCS test of outdoor magnetic fields in Ku band, K band or Ka band.
CN202010959863.7A 2020-09-14 2020-09-14 Integrated support for large-mass low-scattering target RCS test and application thereof Active CN112066207B (en)

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US6246355B1 (en) * 1999-12-22 2001-06-12 Hot/Shot Radar Inspections, Llc Radar cross-section measurement system for analysis of wooden structures
CN200944136Y (en) * 2006-06-02 2007-09-05 中国科学院电子学研究所 Active external scaler of broadband synthetic aperture radar
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CN106556819B (en) * 2016-10-27 2019-07-19 上海无线电设备研究所 Low Scattering Targets bracket of terahertz wave band and preparation method thereof
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