A method and system for rapid modeling of electromagnetic scattering of reinforced concrete targets

Abstract

This invention belongs to the field of electromagnetic scattering modeling technology, and discloses a rapid modeling method and system for electromagnetic scattering of reinforced concrete targets. The modeling process is based on Huygens' principle of electromagnetic fields and high-frequency electromagnetic field calculation methods, combined with a linear antenna radiation model. Through high-frequency electromagnetic scattering mechanism analysis and quantitative calculation, the scattered echoes from reinforced concrete are obtained, forming a rapid simulation capability for the electromagnetic scattering characteristics of reinforced concrete structures. The modeling technology proposed in this invention is applicable to reinforced concrete structural targets of arbitrary shapes and does not limit the embedding method of the reinforcing steel within the concrete (it can be a mesh or other arbitrary embedding shape), laying the groundwork for future research on electromagnetic scattering modeling from simple structures to general complex structures and complex buildings.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic scattering modeling technology, specifically relating to a rapid modeling method and system for electromagnetic scattering of reinforced concrete targets. Background Technology

[0002] High-value fixed building targets (such as hangars, bridges, and other important structures) are mostly composed of reinforced concrete, and their radar characteristics urgently need to be thoroughly understood and grasped. Given the current lack of research reports on this issue both domestically and internationally, conducting theoretical modeling research on the electromagnetic scattering characteristics of such targets has significant theoretical importance and practical engineering application value.

[0003] Reinforced concrete structures are typically complex in shape and have varied internal steel reinforcement structures, making radar scattering characteristic modeling extremely challenging.

[0004] Research on the prediction and application of radar target characteristics still faces two challenges. First, most of the aforementioned methods for calculating electromagnetic scattering characteristics are based on numerical calculations. Numerical calculations of target electromagnetic scattering are often limited by computational resources and cannot effectively calculate electrically large targets, or in many cases, are even incalculable. When the target's electrical size reaches thousands or even tens of thousands of wavelengths, numerical methods often require tens of gigabytes or even terabytes of memory to complete the calculations. High-frequency asymptotic methods, represented by Physical Optics (PO), Physical Theory of Diffraction (PTD), and Shooting and Bouncing Ray (SBR), demonstrate significant advantages in electromagnetic scattering analysis of (ultra)electrically large and complex targets, large-scale scattering characteristic calculations, real-time (quasi-real-time) scattering characteristic calculations, and the design and optimization of characteristic signal control. These advantages include high computational efficiency, extremely low memory consumption, low requirements for computer simulation hardware, clear explanation of physical mechanisms, and ease of optimization design and scattering mechanism analysis.

[0005] Secondly, most existing electromagnetic scattering models, algorithms, and simulation software focus on ideally conductive (PEC) targets. In practical applications, there is an urgent need to extend the modeling scope to targets with mixed metallic and dielectric structures. For example, buildings are mostly composed of reinforced concrete, and their radar characteristics require in-depth understanding and mastery. Compared to PEC targets, electromagnetic scattering of targets with complex dielectric structures involves more complex electromagnetic scattering mechanisms, and their electromagnetic scattering characteristics differ significantly from those of PEC targets, making the electromagnetic scattering modeling process much more complex. Currently, research reports on this issue are scarce both domestically and internationally. Therefore, conducting theoretical modeling research on the electromagnetic scattering characteristics of such targets has significant theoretical importance and practical engineering application value. Summary of the Invention

[0006] The problem addressed by this invention is to provide a rapid modeling method and system for the electromagnetic scattering characteristics of reinforced concrete structural targets. The modeling process is based on Huygens' principle of electromagnetic fields and high-frequency electromagnetic field calculation methods, combined with a linear antenna radiation model. Through high-frequency electromagnetic scattering mechanism analysis and quantitative calculation, the scattered echoes from reinforced concrete are obtained, forming a rapid simulation capability for the electromagnetic scattering characteristics of reinforced concrete structures. The modeling technology proposed in this invention is applicable to reinforced concrete structural targets of arbitrary shapes and does not limit the embedding method of the reinforcing steel within the concrete (it can be a mesh or other arbitrary embedding shape), laying the groundwork for future upgrades and modifications to electromagnetic scattering modeling from simple structures or general complex structures to complex buildings.

[0007] To achieve the above objectives, the present invention adopts the following solution:

[0008] In a first aspect, the present invention provides a method for rapid modeling of electromagnetic scattering of reinforced concrete targets, comprising the following steps:

[0009] Step 1. Construct a geometric model of the reinforced concrete structure and select Huygens surfaces to enclose the geometric model of the reinforced concrete structure;

[0010] Step 2. Decompose the tangential field of the target surface of the reinforced concrete structure geometric model into three scattering mechanism fields, and perform electromagnetic modeling on the three scattering mechanism fields respectively;

[0011] Step 3. Obtain the scattering contribution of the three scattering mechanism fields respectively;

[0012] Step 4. Vector superposition of the scattering contributions of the three scattering mechanisms to obtain the total scattering field of the reinforced concrete structure.

[0013] Furthermore, in step 1, a Huygens surface is selected to surround the reinforced concrete geometric model, and the scattering of the reinforced concrete is represented by a tangential electromagnetic field on the closed surface using Huygens' principle.

[0014] Furthermore, in step 2, the tangential field of the target surface is decomposed into: ① the primary scattering field of the outer surface of the concrete, ② the electromagnetic wave that is first scattered by the steel reinforcement and then passes through the field, and ③ the electromagnetic wave that is first scattered by the inner surface of the concrete and then passes through the field.

[0015] Furthermore, the calculation method for the scattering contribution of the electromagnetic wave first being scattered by the steel bar and then passing through the field in step 3 is as follows:

[0016] (1) Perform ray tracing on the radiation field of the electromagnetic wave that is first scattered by the steel bar and then passes through the field to determine the excited area of ​​the steel bar in the reinforced concrete geometric model and calculate the penetration field of the irradiated area.

[0017] (2) The scattering field of the steel bars in the reinforced concrete geometric model is equivalent to the radiation field of the steel bar line source. The radiation field of a certain excited region of the steel bars in the concrete is calculated based on the excited region of the steel bars in the reinforced concrete geometric model.

[0018] Furthermore, the determination of the excited region of the reinforcing bars in the reinforced concrete geometric model specifically involves: using a finite number of triangular prism beams to simulate the electromagnetic waves penetrating the concrete, treating the reinforcing bars as thin cylinders and no longer performing surface discretization, and calculating the excited region on the reinforcing bars through the geometric intersection determination method of the prisms and thin cylinders.

[0019] Furthermore, the scattering of complex steel reinforcement structures is decomposed into the superposition of radiation from each small segment of steel reinforcement. The steel reinforcement radiation field is constrained to scattering within the bistatic angle range near the back direction. The back scattering contribution of the steel reinforcement radiation field through the concrete is given using physical optics methods.

[0020] Furthermore, in step 3, the scattering contributions of the primary scattering field of the outer surface of the concrete and the scattering field of the electromagnetic wave first scattered by the inner surface of the concrete and then transmitted are calculated using geometric optics and physical optics methods.

[0021] On the other hand, the present invention provides a rapid modeling system for electromagnetic scattering of reinforced concrete targets, comprising:

[0022] Module 1 is used to construct the geometric model of the reinforced concrete structure and selects Huygens surfaces to enclose the reinforced concrete geometric model.

[0023] Module 2 is used to decompose the tangential field of the target surface of the reinforced concrete structure geometric model into three scattering mechanism fields, and to perform electromagnetic modeling on the three scattering mechanism fields respectively.

[0024] Module 3 is used to obtain the scattering contributions of the three scattering mechanism fields respectively;

[0025] Module 4 is used to vector superimpose the scattering contributions of the three scattering mechanism fields to obtain the total scattering field of the reinforced concrete structure.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] I. Rapid prediction of electromagnetic scattering characteristics of large reinforced concrete structures (electrical dimensions can be greater than 10,000 times the wavelength) can be achieved on ordinary computers;

[0028] Second, the concrete can have any complex shape, and the internal steel bars can be embedded in any non-periodic manner.

[0029] Third, it can clearly calculate electromagnetic scattering responses with different mechanisms. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is a flowchart of an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram illustrating the propagation process of electromagnetic waves in a reinforced concrete structure according to an embodiment of the present invention.

[0033] Figure 3 This is a schematic diagram illustrating the transformation between the global coordinate system and the local coordinate system according to an embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of the relative positions of the beam-corresponding surface element and the reinforcing bar in the local coordinate system of an embodiment of the present invention. Figure 1 ;

[0035] Figure 5 This is a schematic diagram of the relative positions of the beam-corresponding surface element and the reinforcing bar in the local coordinate system of an embodiment of the present invention. Figure 2 ;

[0036] Figure 6 This is a schematic diagram of the intersection of the beam and the reinforcing bar in an embodiment of the present invention;

[0037] Figure 7 This is a schematic diagram of a cubic reinforced concrete structure according to an embodiment of the present invention;

[0038] Figure 8 This is a schematic diagram comparing the scattering fields of different mechanisms in a cubic reinforced concrete structure according to an embodiment of the present invention;

[0039] Figure 9 This is a schematic diagram comparing the total scattering field when different numbers of steel bars are placed inside a cubic concrete structure according to an embodiment of the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0041] It should be noted that, in the description of the embodiments of the present invention, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0042] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, without limiting the number of objects; for example, a first object can be one or more. Furthermore, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects have an "or" relationship.

[0043] <Example 1>

[0044] like Figure 1 As shown in the figure, this embodiment provides a method for rapid modeling of electromagnetic scattering of reinforced concrete targets, including the following steps:

[0045] Step 1. Construct a geometric model of the reinforced concrete structure and select Huygens surfaces to enclose the geometric model of the reinforced concrete structure;

[0046] Step 2. Decompose the tangential field of the target surface of the reinforced concrete structure geometric model into three scattering mechanism fields, and perform electromagnetic modeling on the three scattering mechanism fields respectively;

[0047] Step 3. Obtain the scattering contribution of the three scattering mechanism fields respectively;

[0048] Step 4. Vector superposition of the scattering contributions of the three scattering mechanisms to obtain the total scattering field of the reinforced concrete structure.

[0049] In step 1 of this embodiment, the outer surface of the reinforced concrete is taken as a Huygens surface.

[0050] like Figure 2As shown, the tangential field of the target surface is decomposed into: ① the primary scattering field of the outer surface of the concrete, ② the field where the penetrating electromagnetic wave is first scattered by the steel reinforcement and then penetrates, and ③ the field where the penetrating electromagnetic wave is first scattered by the inner surface of the concrete and then penetrates. Electromagnetic modeling of the fields of these three scattering mechanisms is performed using different high-frequency calculation methods.

[0051] The calculation method for the scattering contribution of the electromagnetic wave in step 3, which is first scattered by the steel bar and then passes through the field, is as follows:

[0052] (1) Perform ray tracing on the radiation field of the electromagnetic wave that is first scattered by the steel bar and then passes through the field to determine the excited area of ​​the steel bar in the reinforced concrete geometric model and calculate the penetration field of the irradiated area.

[0053] (2) The scattering field of the steel bars in the reinforced concrete geometric model is equivalent to the radiation field of the steel bar line source. The radiation field of a certain excited region of the steel bars in the concrete is calculated based on the excited region of the steel bars in the reinforced concrete geometric model.

[0054] Among these, ray tracing of the radiation field of the electromagnetic wave that is first scattered by the steel reinforcement and then passes through the field includes:

[0055] See Figure 3 We select the center of the bottom surface of the reinforcing bar as the origin of the local coordinate system (xyz coordinates), and the axis of the reinforcing bar as the z-axis. We establish the local coordinate system by placing the direction vector of the transmitted beam in the xoz plane. Then, we define the corresponding triangular facets of the beam, vertices A, B, and C, and their propagation directions. Transform to a local coordinate system and perform the following judgment steps in the local coordinate system:

[0056] ① Determine if the x-coordinates of all three vertices of a face element are greater than 0. See also Figure 4 If the x-coordinates of the three vertices of the triangular element on the concrete surface corresponding to the beam are all greater than 0, it means that the reinforcing bar is in front of the direction of transmission wave propagation and may be illuminated by the beam, and the next step can be continued; otherwise, the reinforcing bar is behind the direction of transmission wave propagation and cannot be illuminated by the beam.

[0057] ② Determine whether the y-coordinates of the three vertices of the face element are not all greater than 0 or less than 0. See also Figure 5 In the local coordinate system, the straight line containing the reinforcing bar axis is the z-axis of the coordinate system. When the y-coordinates of the three vertices of the surface element are not all greater than 0 or less than 0 (e.g. Figure 3-5 In the middle ΔABC), the beam intersects the z-axis, which may illuminate the reinforcing bar, allowing for further decision-making; conversely, when the y-coordinates of all three vertices of the surface element are less than 0 or greater than 0 (e.g., ... Figure 3-5 In the middle (ΔA′B′C′ and ΔA″B″C″), the beam does not intersect with the z-axis and cannot illuminate the reinforcing bars.

[0058] ③ Calculate the two intersection points of the beam and the z-axis.

[0059] Calculate the y-coordinates of two points E and F on the sides of triangle ABC, where the y-coordinate is 0. Assign the x, y, and z coordinates of the three vertices A, B, and C of the triangle to points N1, N2, and N3, respectively, in ascending order of their y-coordinates. If N2 < 0, then...

[0060]

[0061] Calculate the direction vector of the transmitted wave in the local coordinate system

[0062]

[0063] Calculate the three-dimensional coordinates of the projections of points E and F along the wave vector direction onto the z-axis, specifically points G and H. (See also...) Figure 6 The z-coordinates of points G(x,y,z) and H(x,y,z) are as follows:

[0064] ④ Determine the excited area on the surface of the reinforcing bar. Let the length of the reinforcing bar be H, and let m1 = min(G z ,H), m1=max(G z If m2 < 0 || m1 > H, then the reinforcing bar cannot be excited by this beam; if m1 < 0, then in the local coordinate system, the interval in which the reinforcing bar is excited by this beam is a cylinder with point O′(x,y,z) = (0,0,m2 / 2) as the center and height h = m2; if m1 > H, then O′(x,y,z) = (0,0,m2 / 2+h / 2) and height h = H - m1; if m1 ≥ 0 && m2 ≤ H, then O′(x,y,z) = (0,0,m1 / 2+m2 / 2) and h = m2 - m1.

[0065] The calculation of the radiation field of steel reinforcement that can penetrate concrete includes:

[0066] According to the induction theorem, when a steel bar is irradiated by a ray beam, an induced current is generated on its surface, which is the equivalent source of the scattered field. The scattered field of the steel bar structure can be equivalent to the radiation field of the "steel bar wire source". The "steel bar wire source" model is based on the "wire antenna" model and adds backpropagation constraints to correspond to the back echo received by radar. According to the incremental length diffraction coefficient (ILDC) theory, "the scattered field generated by any shape of edge can be obtained by integrating its irradiated part". That is, each small segment is modeled using the so-called "incremental length" method. Integrating the current on the induced surface yields the radiation field of the finite-length "steel bar wire source".

[0067] The smaller the target electrical size, the smaller its near-field range. When calculating the contribution of the steel reinforcement's radiated field penetrating the concrete surface, the concrete surface is finely subdivided. In this case, each tiny surface element of the concrete surface is located in the far-field region of the steel reinforcement's radiated field. That is, for any point on a single surface element, the steel reinforcement's radiated field is a uniform plane wave, and the magnitude and phase of the field can be determined by the spatial relative position of the surface element center and the excited region. The radiated field of a certain excited region of the steel reinforcement within the concrete is:

[0068]

[0069] In the formula, These represent the radiation field components for horizontal and vertical polarization, respectively; E0 is the incident electric field amplitude; θ s and These are the elevation and azimuth angles in the receiving direction, respectively; k0 and k c Let M and N be the wave vector constants in free space and concrete, respectively; r is the distance from the origin to the field point; M and N have the following forms:

[0070]

[0071] The contribution of the radiant field from the reinforcing steel bars to the concrete surface was calculated using physical optics methods. Furthermore, geometrical optics and physical optics methods were used to calculate the scattering and penetration-reflection-exit scattering contributions from the concrete surface.

[0072] The total scattering field of the reinforced concrete structure is obtained by superimposing the scattering contribution of the steel reinforcement, the scattering field of the concrete surface, and the penetration-reflection-penetration field vectors.

[0073] like Figure 7 As shown, the geometric model of the reinforced concrete structure constructed in this embodiment has an outer side length of 8 meters and contains 84 steel bars, each 6 meters long and 0.03 meters in radius.

[0074] like Figure 8 As shown, under the conditions of 5 GHz input frequency, VV polarization, and θ = 90°, the reinforced concrete structure constructed in this embodiment has the strongest backscattered total field when the azimuth angle is 0°, ±90°, and ±180°; and the backscattered total field is relatively weak when the azimuth angle is ±45° and ±135°.

[0075] like Figure 9As shown, with the increase of the number of built-in steel bars, the scattering contribution of the induced current radiated by the steel bars and then transmitted through the concrete surface becomes larger and larger, and the total field gradually increases accordingly. However, at azimuth angles of 0°, ±90°, and ±180°, the propagation direction of the incident electromagnetic wave is perpendicular to the outer surface of the cubic concrete. The primary scattering field of the outer surface is very strong and dominates the total field. Therefore, the increase of the number of steel bars has no significant effect on the change of the total scattering field at these attitudes, which is consistent with theoretical knowledge.

[0076] This embodiment, taking into account the geometric characteristics of reinforced concrete structures (concrete piers, bridges, buildings), innovatively proposes a tracing method suitable for penetrating ray fields within reinforced concrete structures, drawing on traditional ray tracing approaches. This method is used to determine the irradiated (or excited) area of ​​the reinforcing steel within the concrete and to calculate the penetrating field of the irradiated area. A finite number of triangular prism beams are used to simulate the penetrating electromagnetic waves within the concrete. The reinforcing steel is treated as a thin cylinder and surface discretization is no longer performed. The excited area on the reinforcing steel is calculated using a geometric intersection method between the prisms and the thin cylinders. This avoids the cumbersome triangular element intersection calculations in traditional ray tracing methods. The time complexity of ray tracing within concrete is reduced from M*N to M+m (where M is the number of rough subdivisions on the outer surface of the concrete, and m is the number of embedded reinforcing steel bars within the concrete), significantly reducing ray tracing time and making the tracing of the radiating ray field of the reinforcing steel within concrete efficient and feasible.

[0077] The scattering of complex steel reinforcement structures is appropriately decomposed into the superposition of radiation from each small segment of steel reinforcement, and no further meshing is performed. Based on the principle of capturing the main scattering contribution of steel reinforcement, the radiation field of steel reinforcement is constrained to the scattering within the bistatic angle range near the back direction. Finally, the back scattering contribution of the steel reinforcement radiation field through the concrete is given by physical optics method, realizing the calculation of electromagnetic scattering characteristics of electrically small curved surface targets inside the medium.

[0078] The PO method and the GO-GO-PO algorithm are used to calculate the primary scattering field and the penetration-reflection-transmission field of complex media. Geometric optics is used to determine the ray path on the surface and inside the target medium, and physical optics methods are used to calculate the primary scattering field on the surface and the contribution of the transmitted wave, which is reflected and refracted after passing through the inner surface of the medium, to the scattering field.

[0079] <Example 2>

[0080] This second embodiment provides a rapid modeling system for electromagnetic scattering of reinforced concrete targets, including:

[0081] Module 1 is used to construct the geometric model of the reinforced concrete structure and selects Huygens surfaces to enclose the reinforced concrete geometric model.

[0082] Module 2 is used to decompose the tangential field of the target surface of the reinforced concrete structure geometric model into three scattering mechanism fields, and to perform electromagnetic modeling on the three scattering mechanism fields respectively.

[0083] Module 3 is used to obtain the scattering contributions of the three scattering mechanism fields respectively;

[0084] Module 4 is used to vector superimpose the scattering contributions of the three scattering mechanism fields to obtain the total scattering field of the reinforced concrete structure.

[0085] The specific working processes of the units and modules in the above system can be referred to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the division of the above functional units and modules is only used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the system can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application.

[0086] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0087] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this invention can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0088] In the embodiments provided by this invention, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the system embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or modules may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0089] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0090] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0091] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of the above embodiments of the power system transient stability adaptive evaluation method considering PMU data loss. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0092] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for fast modeling of electromagnetic scattering from a reinforced concrete target, characterized in that, The method comprises the following steps: Step 1. Construct a reinforced concrete structure geometric model, and select a Huygens surface to surround the reinforced concrete geometric model; Step 2. Decompose the target surface tangential field of the reinforced concrete structure geometric model into three kinds of scattering mechanism fields, and perform electromagnetic modeling on the three kinds of scattering mechanism fields respectively; the target surface tangential field is decomposed into: ① a first scattering field of the concrete outer surface, ② a field that the penetrating electromagnetic wave is scattered by the steel bars first and then penetrates out, and ③ a field that the penetrating electromagnetic wave is scattered by the inner surface of the concrete first and then penetrates out; Step 3. Obtain the scattering contributions of the three kinds of scattering mechanism fields respectively; the scattering contribution calculation method of the field that the penetrating electromagnetic wave is scattered by the steel bars first and then penetrates out is as follows: (1) Perform ray tracing on the radiation field of the field that the penetrating electromagnetic wave is scattered by the steel bars first and then penetrates out, judge the excited region of the steel bars in the reinforced concrete geometric model, and calculate the penetration field of the irradiated region; (2) Equivalent the scattering field of the steel bars in the reinforced concrete geometric model into the radiation field of the steel bar line source, and calculate the radiation field of a certain excited region of the steel bars in the concrete based on the excited region of the steel bars in the reinforced concrete geometric model; The judgment of the excited region of the steel bars in the reinforced concrete geometric model is specifically: simulate the penetrating electromagnetic wave in the concrete with a limited number of triangular prism beams, regard the steel bars as thin cylinders and do not perform surface discretization again, and calculate the excited region on the steel bars by a geometric intersection judgment method of the prisms and the thin cylinders; Step 4. Vector superimpose the scattering contributions of the three kinds of scattering mechanism fields to obtain the total scattering field of the reinforced concrete structure.

2. The method of claim 1, wherein, In step 1, the Huygens surface is selected to surround the reinforced concrete geometric model, and the scattering of the reinforced concrete is represented by the tangential electromagnetic field on the closed surface according to the Huygens principle.

3. The method of claim 1, wherein, The scattering of the complex steel structure is decomposed into the superposition of the radiation of each small section of the steel, the radiation field of the steel is constrained to the scattering in the backward nearby double-station angle range, and the backward scattering contribution of the steel radiation field penetrating out of the concrete is given by the physical optics method.

4. The method of claim 1, wherein, In step 2, the scattering contributions of the concrete outer surface first scattering field and the field that the penetrating electromagnetic wave is scattered by the inner surface of the concrete first and then penetrates out are calculated by the geometric optics and physical optics methods.

5. A system for fast modeling of electromagnetic scattering from a reinforced concrete object, characterized in that, It comprises: Module one is used for constructing a reinforced concrete structure geometric model, and selecting a Huygens surface to surround the reinforced concrete geometric model; Module two is used for decomposing the target surface tangential field of the reinforced concrete structure geometric model into three kinds of scattering mechanism fields, and performing electromagnetic modeling on the three kinds of scattering mechanism fields respectively; Module three is used for obtaining the scattering contributions of the three kinds of scattering mechanism fields respectively; Module four is used for vector superimposing the scattering contributions of the three kinds of scattering mechanism fields to obtain the total scattering field of the reinforced concrete structure; The reinforced concrete target electromagnetic scattering fast modeling system is used for executing the steps in the reinforced concrete target electromagnetic scattering fast modeling method in any one of claims 1-4. ​

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