Method, device, equipment and storage medium for quickly acquiring structural frequency of pedestrian bridge

Abstract

This invention provides a method, device, equipment, and storage medium for rapidly acquiring the structural frequency of pedestrian bridges. By visually determining the geometric and material information of a pedestrian bridge, a pedestrian bridge benchmark model is generated. A sample library of geometric and material parameters and structural frequencies is then established to rapidly acquire the structural frequency of the pedestrian bridge. This model, without relying on architectural drawings, allows for rapid and reliable acquisition of the structural frequency of pedestrian bridges, significantly impacting health monitoring and maintenance management during the operational life of pedestrian bridges.

Description

Technical Field

[0001] The present invention relates to the field of civil engineering, and in particular to a method, device, equipment and storage medium for quickly acquiring the structural frequency of a pedestrian bridge. Background Art

[0002] With the rapid development of urban road networks, pedestrian bridges are being designed more gently. The vibration comfort of structures under pedestrian loads has become a primary design criterion. To ensure vibration comfort during the operational phase, my country's "Technical Specifications for Urban Pedestrian Bridges and Pedestrian Underpasses" (CJJ69-1995) stipulates that the vertical natural frequency of structures should not be less than 3 Hz. Therefore, how to reasonably estimate the structural frequency of pedestrian bridges has become a key issue that needs to be addressed in pedestrian bridge design. Furthermore, my country currently has a large number of urban pedestrian bridges (nearly one million). As their service life increases, these bridges will inevitably face a series of problems such as performance degradation. Therefore, health monitoring and operation and maintenance management of pedestrian bridges during their operational life are urgent. As a key reference indicator for structural damage assessment, the accuracy of structural frequency is crucial for evaluating the health of pedestrian bridges. Therefore, developing accurate and efficient methods for estimating the frequency of pedestrian bridges to meet the structural design and operation and maintenance requirements of large-scale urban pedestrian bridges is undoubtedly of great significance.

[0003] Currently, there are two main approaches to calculating the structural frequency of pedestrian bridges in engineering practice. First, software modeling based on design drawings, most commonly using Midas Civil, relies on complex modeling processes. Furthermore, due to differences between design and actual construction, actual results can differ from these simulations. Second, conducting on-site dynamic measurements is another means of determining the frequency of pedestrian bridges. However, while this contact measurement method is highly accurate, it can only be measured on a single bridge, resulting in low test efficiency and high costs. In practice, obtaining large-scale test samples is difficult.

[0004] Therefore, the inability to balance the accuracy and efficiency of frequency measurement of existing pedestrian bridge structures is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] To address the above-mentioned technical issues, the present invention provides a method, device, equipment, and storage medium for rapidly acquiring the structural frequency of a pedestrian bridge. By visually determining the geometric and material information of a pedestrian bridge, a pedestrian bridge benchmark model is generated. A sample library of pedestrian bridge geometry and material parameters and structural frequencies is then established to rapidly acquire the structural frequency of the pedestrian bridge. This model, without relying on architectural drawings, allows for rapid and reliable acquisition of the structural frequency of a pedestrian bridge, significantly impacting health monitoring and maintenance management during its operation.

[0006] According to a first aspect of the present invention, a method for quickly acquiring the structural frequency of a pedestrian bridge is provided, comprising the following steps:

[0007] S1: Obtain the geometric parameters and material parameters of the footbridge;

[0008] S2: Establish a benchmark model of the pedestrian bridge under test based on geometric parameters and material parameters;

[0009] S3: Based on the Benchmark model, the structural frequency of the pedestrian bridge is calculated using the conversion relationship between kinetic energy and strain energy;

[0010] S4: Repeat steps S1-S3 to obtain multiple sets of samples and establish a sample library of geometric and material parameters-structure frequencies of pedestrian bridges;

[0011] S5: Conduct field measurements and random sampling tests on small samples to revise the sample library in step S4, and obtain a corrected sample library of geometric and material parameters-structural frequencies of footbridges;

[0012] S6: Based on the pedestrian bridge geometry and material parameters - structural frequency correction sample library, a statistical analysis method is used to achieve rapid estimation of the pedestrian bridge structural frequency.

[0013] Furthermore, in step S1, obtaining geometric parameters and material parameters of the pedestrian bridge specifically includes:

[0014] The geometric parameters of the pedestrian bridge are obtained based on the GPS satellite positioning system and 3D laser scanning technology; the material parameters of the pedestrian bridge are obtained based on computer vision deep learning technology.

[0015] Furthermore, the geometric parameters include: span, cross-sectional dimensions, beam height, bridge deck width, and beam bottom width; and the material parameters include: concrete or steel.

[0016] Furthermore, in step S2, establishing the benchmark model of the pedestrian bridge under test includes: designing a cross section based on appearance geometric parameters, and obtaining the moment of inertia of the bridge cross section based on the cross section.

[0017] Furthermore, the cross-sectional bending stiffness of a footbridge is only related to its appearance geometric parameters.

[0018] Furthermore, in step S3, the structural frequency of the pedestrian bridge is calculated based on the Benchmark model using the conversion relationship between kinetic energy and strain energy. The specific calculation formula is as follows:

[0019]

[0020] Where: E is the elastic modulus, in units of Pa ;I is the moment of inertia of the cross section, in units of ; is the deflection, in units of m ; To find the second derivative of the deflection, the unit is ; Calculated value for the structural frequency.

[0021] Furthermore, in step S5, the on-site measurement and sampling test of a small sample are carried out to correct the sample library in step S4 to obtain a corrected sample library of geometric and material parameters-structural frequency of the pedestrian bridge. The specific correction formula is as follows:

[0022]

[0023] Where, is the frequency correction coefficient, which is obtained by fitting the deviation between the measured sample and the predicted value; is the calculated value of the structural frequency; is the corrected structural frequency.

[0024] According to a second aspect of the present invention, a device for quickly acquiring the structural frequency of a pedestrian bridge is provided, comprising the following modules:

[0025] Parameter acquisition module, used to obtain geometric parameters and material parameters of the pedestrian bridge;

[0026] Benchmark model building module, used to build the benchmark model of the pedestrian bridge under test based on geometric parameters and material parameters;

[0027] The structural frequency calculation module is used to calculate the structural frequency of the pedestrian bridge based on the Benchmark model and the conversion relationship between kinetic energy and strain energy;

[0028] A sample library establishment module is used to repeat the operations from the parameter acquisition module to the structural frequency calculation module to obtain multiple sets of samples and establish a pedestrian bridge geometry and material parameter-structural frequency sample library;

[0029] The sample library correction module is used to carry out on-site measurement and sampling inspection of small samples, correct the sample library, and obtain the corrected sample library of geometric and material parameters-structure frequency of pedestrian bridges;

[0030] The structural frequency estimation module is used to quickly estimate the structural frequency of pedestrian bridges through statistical analysis methods based on the pedestrian bridge geometry and material parameters-structural frequency correction sample library.

[0031] According to a third aspect of the present invention, the present invention provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the method for rapidly acquiring the structural frequency of a pedestrian bridge are implemented.

[0032] According to a fourth aspect of the present invention, the present invention provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for quickly acquiring the structural frequency of a pedestrian bridge.

[0033] The technical solution provided by the present invention has the following beneficial effects:

[0034] 1. It was demonstrated that under the existing pedestrian bridge structural design paradigm (designed according to current specifications), the cross-sectional bending stiffness of a pedestrian bridge is only related to its external dimensions, and its internal details (such as ribs) have little effect on its bending stiffness. Therefore, a standardized bridge design can be performed by simply determining the external dimensions and materials, resulting in an equivalent model (benchmark model) with bending stiffness close to that of an actual bridge.

[0035] 2. Through non-contact measurement methods (GPS satellite positioning system and 3D laser scanning technology) and mature computer vision technology, the geometric parameters and material information of the pedestrian bridge can be quickly obtained, and the stiffness of the pedestrian bridge can be quickly estimated without the need for structural design drawings and on-site surveys. This greatly saves time, manpower and material costs, and paves the way for the large-scale application of this technology.

[0036] 3. The mapping relationship between the geometric (material) parameters of the pedestrian bridge and its structural frequency was established, and based on this, a fast and accurate estimation of the structural frequency of a given pedestrian bridge was achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0038] Figure 1 It is a schematic diagram of a rectangle without stiffening ribs;

[0039] Figure 2 It is a schematic diagram of rectangular ribbed;

[0040] Figure 3 It is a schematic diagram of a trapezoid without stiffening ribs;

[0041] Figure 4 It is a schematic diagram of trapezoidal ribs;

[0042] Figure 5 This is an overall flow chart of a method for quickly acquiring the structural frequency of a pedestrian bridge according to the present invention;

[0043] Figure 6This is a real picture of the pedestrian bridge of the present invention;

[0044] Figure 7 This is a simplified diagram of bridge calculations according to the present invention;

[0045] Figure 8 is a schematic cross-sectional view of the bridge of the present invention;

[0046] Figure 9 Schematic diagram of the cross section of the bridge structure of the present invention;

[0047] Figure 10 This is the time domain diagram of the measured pedestrian bridge of the present invention;

[0048] Figure 11 This is the frequency domain diagram of the pedestrian bridge measured in the present invention;

[0049] Figure 12 This is a general structural diagram of a device for quickly acquiring the structural frequency of a pedestrian bridge according to the present invention;

[0050] Figure 13 The figure is a schematic structural diagram of an electronic device of the present invention. DETAILED DESCRIPTION

[0051] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0052] First, the theoretical basis and technical support for the feasibility of the present invention are explained:

[0053] Preliminary research has shown that pedestrian bridges are mostly steel box-type beams. For this type of beam structure, the main factors affecting the frequency are the bridge span and cross-sectional dimensions. Other factors, such as steel plate thickness and the presence or absence of ribs, have a very limited impact on the frequency. The following calculations, for rectangular and trapezoidal cross-sections, show different steel plate thicknesses and the presence or absence of ribs, and the resulting frequencies. The results demonstrate that the influence of these thicknesses and the presence or absence of ribs on the frequency is very limited.

[0054] Considering two common bridge cross-section types, rectangular and trapezoidal, a total of 12 working conditions are calculated (see below for specific working condition settings). The frequency calculation is performed using the natural frequency calculation formula of a single-span bridge (Equations 1.1 and 1.2):

[0055] (1.1)

[0056] (1.2)

[0057] Category 1: Rectangular cross-section (proposed bridge length 40m, bridge deck width 4m, box girder height 50cm)

[0058] In combination with existing pedestrian bridge design specifications, for the given geometric dimensions, three steel plate thicknesses are considered: 12mm, 14mm, and 16mm. For each plate thickness, two working conditions are considered, one with stiffening ribs and one without stiffening ribs, for a total of six working conditions. The cross-section of the bridge without stiffening ribs is shown in the figure below. Figure 1 As shown in the figure, the cross section of the bridge with stiffening ribs is as follows Figure 2 As shown. Conventional Q235 steel is used, with an elastic modulus of E=200GPa and a density of 7.85g / cm 3 .

[0059] The calculation results are shown in Table 1.

[0060] Table 1 Calculation results of rectangular cross-section

[0061]

[0062] Category 2: Trapezoidal cross-section (proposed bridge length 40m, bridge deck width 4m, height 42cm, hypotenuse 115cm, base 218cm)

[0063] In combination with the existing pedestrian bridge design specifications, for the given geometric dimensions, three steel plate thicknesses are set: 12mm, 14mm, and 16mm. Each thickness is considered with and without ribs, for a total of 6 working conditions. The cross-section of the bridge without stiffening ribs is shown in the figure below. Figure 3 As shown in the figure, the cross section of the bridge with stiffening ribs is as follows Figure 4 As shown. Conventional Q235 steel is used, with an elastic modulus of E=200GPa and a density of 7.85g / cm 3 .

[0064] The calculation results are shown in Table 2.

[0065] Table 2 Calculation results of trapezoidal cross section

[0066]

[0067] Based on the above calculation results, it can be seen that when the bridge's external dimensions are constant, the steel plate thickness and the presence of ribs have little impact on the structural frequency. In other words, given the fixed external dimensions, the internal structure has a very limited and negligible effect on the structural frequency. This also proves that under the current pedestrian bridge structural design paradigm, the cross-sectional bending stiffness of a pedestrian bridge is only related to its external dimensions, and its internal details (such as ribs) have little impact on its bending stiffness. Therefore, when estimating the structural frequency, it is not necessary to focus on the bridge's internal structure; only the geometric dimensions (such as span and beam height) and initial design parameters (such as materials) are required.

[0068] Existing, mature 3D surveying and mapping technologies enable large-scale, non-contact measurements with accuracy that meets engineering requirements at low cost. They can effectively calculate the span and geometry of pedestrian bridges. With this information, the natural frequency of a pedestrian bridge can be effectively estimated based on equations (1.1) and (1.2). After modification, a method for rapidly estimating the frequency of pedestrian bridges has been established.

[0069] Based on the aforementioned theoretical foundations and technical support, an embodiment of the present invention provides a method for rapidly acquiring the structural frequency of a pedestrian bridge. This method uses visual methods to determine the bridge's geometry and material information, generating a pedestrian bridge benchmark model. This model then establishes a sample library of pedestrian bridge geometry and material parameters and structural frequencies, enabling rapid acquisition of the bridge's structural frequency. This model, without relying on architectural drawings, allows for rapid and reliable acquisition of the bridge's structural frequency, significantly impacting health monitoring and maintenance management during its operational life.

[0070] Currently, urban pedestrian bridges primarily span main urban streets (30m-60m), and their primary structural form is a single-span or two-span beam bridge. This example uses a single-span pedestrian bridge as an example, but the relevant methods and conclusions can also be extended to analyze two-span or multi-span pedestrian bridges.

[0071] The primary starting point or principle of this embodiment is that, under the existing pedestrian bridge structural design paradigm, the cross-sectional bending stiffness of a pedestrian bridge is only related to its external dimensions, while its internal structural details (such as ribs) have little impact on its bending stiffness. This principle is demonstrated below through a specific embodiment.

[0072] In this embodiment, the three-dimensional coordinates of the ground object are acquired by using a satellite positioning measurement system (GPS) and three-dimensional imaging technology to obtain the geometric and material information of the bridge. On this basis, a pedestrian bridge benchmark model is established; the first-order vertical frequency of the pedestrian bridge is determined based on a simplified theoretical method, and on this basis, a mapping sample library of the geometric (material) parameters-structural frequency of the pedestrian bridge is established; small sample field measurements are carried out to test the sample library, and on this basis, necessary corrections are made to the sample library to obtain a corrected pedestrian bridge geometric (material) parameter-structural frequency sample library. Based on this sample library, statistical analysis is carried out under large samples to determine the mapping relationship between the structural frequency of the pedestrian bridge and the geometric (material) parameters, and a method for quickly estimating the frequency of the pedestrian bridge is established. The specific process of this embodiment is as follows. Figure 5 As shown, the method specifically includes the following steps:

[0073] S1: Obtain the geometric parameters and material parameters of the footbridge;

[0074] Specifically, the key geometric parameters (span, cross-sectional dimensions) of the pedestrian bridge are determined based on the GPS satellite positioning system and three-dimensional laser scanning technology (mainly through three-dimensional laser scanners and airborne laser scanners); the main material of the bridge (concrete or steel) is determined based on the currently mature computer vision deep learning technology.

[0075] Aerial photographs or satellite photos are obtained through any type of measurement sensor (such as aerial cameras, airborne lidar, etc.), and model / digital conversion is performed with the help of image scanners. The obtained digital data is corrected, transformed, classified and identified in the image processing system. The image processing system consists of hardware (computers, displays, digitizers, etc.) and software (with data input, output, correction, identification and other functions).

[0076] Take a pedestrian overpass in Wuhan as an example, the actual bridge scene is as follows Figure 6 As shown. This pedestrian bridge has external guardrails and a roof, no trusses, and a three-span simply supported beam structure. First, based on the GPS satellite positioning system and 3D laser scanning technology, the effective span of the bridge was obtained to be 8.4+27.4+12.1m, the beam height was 1.12m, the bridge deck width was 4.00m, and the beam bottom width was 2.18m. Based on the above parameter information, the bridge calculation diagram ( Figure 7 ) and beam cross-section diagram ( Figure 8 ). Based on computer vision methods, it is determined that the bridge is a steel structure bridge.

[0077] S2: Establish a benchmark model of the pedestrian bridge under test based on geometric parameters and material parameters;

[0078] Specifically, based on the above-mentioned geometric parameters and material parameters, the Benchmark model design of the bridge was carried out (mainly cross-section design based on appearance geometric parameters).

[0079] The above has proved that under the existing pedestrian bridge structural design paradigm, the cross-sectional bending stiffness of a pedestrian bridge is only related to its external dimensions, and its internal detailed structure (such as ribs, etc.) has little effect on its bending stiffness. Therefore, the cross-sectional design of this bridge can be carried out under the existing pedestrian bridge structural design paradigm. Figure 9 A cross-sectional design drawing of the bridge is provided. Based on this cross-section, the moment of inertia of the bridge section can be calculated as I = 0.0384m4. Based on the material properties of the steel, the material parameters of the bridge can be determined: the elastic modulus is E = 200GPa and the density is 7.85g / cm3.

[0080] S3: Based on the Benchmark model, the structural frequency of the pedestrian bridge is calculated using the conversion relationship between kinetic energy and strain energy;

[0081] Specifically, the structural frequency of the pedestrian bridge is calculated based on the classical energy method. According to the law of conservation of energy, during the vibration of the pedestrian bridge, the frequency of the structure is solved by using the conversion relationship between kinetic energy and strain energy. The frequency of a single-span pedestrian bridge is solved as shown in formula (1.3), while for a multi-span pedestrian bridge, it is only necessary to specify the corresponding displacement function and substitute it into formula (1.3) to solve its frequency. Figure 7 The calculation diagram shown is combined with the moment of inertia I = 0.0384m obtained in step S2 4 Substituting the material parameters into formula (1.3), the calculated frequency of the pedestrian bridge is 5.892 Hz.

[0082] (1.3)

[0083] Where: E is the elastic modulus, in units of Pa ; I is the moment of inertia of the cross section, in units of ; is the deflection, in units of m ; To find the second derivative of the deflection, the unit is ; Calculated value for the structural frequency.

[0084] S4: Repeat steps S1-S3 to obtain multiple sets of samples and establish a sample library of geometric and material parameters-structure frequencies of pedestrian bridges;

[0085] Repeating steps S1-S3, similar methods can be used to obtain the structural geometric (material) parameters and structural frequencies for different pedestrian bridges. GPS satellite positioning systems and 3D laser scanning technology clearly facilitate this work. Without the need for on-site inspections, computers can quickly obtain a large sample of pedestrian bridge data. Based on this, a sample library of pedestrian bridge geometric (material) parameter-structural frequency mappings was established.

[0086] S5: Conduct field measurements and random sampling tests on small samples to revise the sample library in step S4, and obtain a corrected sample library of geometric and material parameters-structural frequencies of footbridges;

[0087] Still Figure 6 Taking the pedestrian bridge shown in the figure as an example, we carried out field measurements. The time history curve of the pedestrian bridge is as follows Figure 10 As shown, the frequency domain diagram of the bridge is obtained after Fourier transform. Figure 11 As shown, the first-order frequency is 5.243 Hz, which is the measured frequency of the footbridge.

[0088] From the above, we can see that the first-order frequency of the bridge obtained by actual measurement is 5.243Hz, which is close to the predicted (calculated) result of 5.892Hz in step S3 (the error is 12.37%). In order to further improve the prediction accuracy, the frequency correction coefficient is introduced. , is a coefficient related to the bridge type (length, width, and ancillary components). Formula (1.3) is modified to obtain Formula (1.4). The bridge frequency correction coefficient is related to the bridge type, span, and ancillary components. It can be determined by fitting the deviation between the measured sample and the predicted value. This results in a corrected sample library of pedestrian bridge geometric (material) parameters and structural frequency corrections.

[0089] (1.4)

[0090] Where, is the frequency correction coefficient, which is obtained by fitting the deviation between the measured sample and the predicted value; is the calculated value of the structural frequency; is the corrected structural frequency.

[0091] S6: Based on the pedestrian bridge geometry and material parameters - structural frequency correction sample library, a statistical analysis method is used to achieve rapid estimation of the pedestrian bridge structural frequency.

[0092] Based on the revised pedestrian bridge geometric (material) parameter-structural frequency correction sample library, a rapid estimation method for pedestrian bridge structural frequency is established through statistical analysis methods (taking into account the influence of different material types, number of spans, and beam types).

[0093] According to the above steps, in practice, it is only necessary to use the GPS satellite positioning system and 3D laser scanning technology to obtain the initial geometric parameters of the bridge, such as span, beam height, and support form. Based on the deep learning method, the bridge material (steel bridge or concrete bridge) can be determined to determine the structural frequency of the pedestrian bridge under test, thus achieving a one-to-one mapping between the geometric (material) parameters of the pedestrian bridge and the structural frequency.

[0094] A device for quickly acquiring the structural frequency of a pedestrian bridge provided by the present invention is described below. The device for quickly acquiring the structural frequency of a pedestrian bridge described below and the method for quickly acquiring the structural frequency of a pedestrian bridge described above can be referred to each other.

[0095] like Figure 12 As shown, a device for quickly acquiring the structural frequency of a pedestrian bridge includes the following modules:

[0096] Parameter acquisition module 01, used to obtain geometric parameters and material parameters of the pedestrian bridge;

[0097] Benchmark model building module 02 is used to build a benchmark model of the pedestrian bridge under test based on geometric parameters and material parameters;

[0098] Structural frequency calculation module 03 is used to calculate the structural frequency of the pedestrian bridge based on the Benchmark model and the conversion relationship between kinetic energy and strain energy;

[0099] The sample library establishment module 04 is used to repeat the operations from the parameter acquisition module to the structural frequency calculation module to obtain multiple sets of samples and establish a pedestrian bridge geometry and material parameter-structural frequency sample library;

[0100] Sample library correction module 05 is used to carry out on-site measurement and sampling inspection of small samples, correct the sample library, and obtain the corrected sample library of geometric and material parameters-structure frequency of pedestrian bridges;

[0101] The structural frequency estimation module 06 is used to realize the rapid estimation of the structural frequency of the pedestrian bridge through statistical analysis methods based on the pedestrian bridge geometry and material parameters-structural frequency correction sample library.

[0102] like Figure 13 As shown, an example of a physical structure diagram of an electronic device is shown, which may include: a processor 610, a communication interface 620, a memory 630 and a communication bus 640, wherein the processor 610, the communication interface 620, and the memory 630 communicate with each other through the communication bus 640. The processor 610 can call the logic instructions in the memory 630 to execute the steps of the above-mentioned method for quickly obtaining the structural frequency of a pedestrian bridge, which specifically include: obtaining the geometric parameters and material parameters of the pedestrian bridge; establishing a benchmark model of the pedestrian bridge under test based on the geometric parameters and material parameters; calculating the structural frequency of the pedestrian bridge based on the benchmark model using the conversion relationship between kinetic energy and strain energy; repeating the above steps to obtain multiple groups of samples and establish a pedestrian bridge geometric and material parameter-structural frequency sample library; conducting on-site measurements and sampling inspections of small samples, correcting the sample library, and obtaining a pedestrian bridge geometric and material parameter-structural frequency corrected sample library; based on the pedestrian bridge geometric and material parameter-structural frequency corrected sample library, achieving rapid estimation of the pedestrian bridge structural frequency through statistical analysis methods.

[0103] Furthermore, the logic instructions in the aforementioned memory 630 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product, stored in a storage medium, includes instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage media include various media capable of storing program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0104] On the other hand, an embodiment of the present invention further provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-mentioned method for quickly acquiring the structural frequency of a pedestrian bridge, specifically including: obtaining the geometric parameters and material parameters of the pedestrian bridge; establishing a benchmark model of the pedestrian bridge under test based on the geometric parameters and material parameters; calculating the structural frequency of the pedestrian bridge based on the benchmark model using the conversion relationship between kinetic energy and strain energy; repeating the above steps to obtain multiple groups of samples and establish a sample library of geometric and material parameters-structural frequencies of pedestrian bridges; conducting on-site measurements and sampling tests of small samples, correcting the sample library, and obtaining a corrected sample library of geometric and material parameters-structural frequencies of pedestrian bridges; based on the corrected sample library of geometric and material parameters-structural frequencies of pedestrian bridges, achieving rapid estimation of the structural frequency of pedestrian bridges through statistical analysis methods.

[0105] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or system. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or system comprising the element.

[0106] The serial numbers of the embodiments of the present invention are for descriptive purposes only and do not represent superiority or inferiority of the embodiments. In a unit claim that lists several means, several of these means may be embodied by the same item of hardware. The use of the terms first, second, and third, etc., does not denote any order and should be construed as identifiers.

[0107] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for quickly acquiring the structural frequency of a pedestrian bridge, characterized in that: The following steps are involved: S1: Obtain the geometric parameters and material parameters of the footbridge; S2: Establish a benchmark model of the pedestrian bridge under test based on geometric parameters and material parameters; S3: Based on the Benchmark model, the structural frequency of the pedestrian bridge is calculated using the conversion relationship between kinetic energy and strain energy; S4: Repeat steps S1-S3 to obtain multiple sets of samples and establish a sample library of geometric and material parameters-structure frequencies of pedestrian bridges; S5: Conduct field measurements and random sampling tests on small samples to revise the sample library in step S4, and obtain a corrected sample library of geometric and material parameters-structural frequencies of footbridges; S6: Based on the pedestrian bridge geometry and material parameters - structural frequency correction sample library, a statistical analysis method is used to achieve rapid estimation of the pedestrian bridge structural frequency.

2. The method for quickly acquiring the structural frequency of a pedestrian bridge according to claim 1, characterized in that: In step S1, the geometric parameters and material parameters of the pedestrian bridge are obtained, specifically including: Obtain the geometric parameters of the pedestrian bridge based on the GPS satellite positioning system and 3D laser scanning technology; Obtain the material parameters of the pedestrian bridge based on computer vision deep learning technology.

3. The method for quickly acquiring the structural frequency of a pedestrian bridge according to claim 1, characterized in that: The geometric parameters include: span, cross-sectional dimensions, beam height, bridge deck width and beam bottom width; the material parameters include: concrete or steel.

4. The method for quickly acquiring the structural frequency of a pedestrian bridge according to claim 1, characterized in that: In step S2, establishing a benchmark model of the pedestrian bridge under test includes: designing a cross section based on appearance geometric parameters, and obtaining the moment of inertia of the bridge cross section based on the cross section.

5. The method for quickly acquiring the structural frequency of a pedestrian bridge according to claim 4, characterized in that: The cross-sectional bending stiffness of a pedestrian bridge is only related to its appearance geometric parameters.

6. The method for quickly acquiring the structural frequency of a pedestrian bridge according to claim 1, characterized in that: In step S3, the structural frequency of the footbridge is calculated based on the Benchmark model using the conversion relationship between kinetic energy and strain energy. The specific calculation formula is as follows: Where: E is the elastic modulus, in units of Pa ; I is the moment of inertia of the cross section, in units of ; is the deflection, in units of m ; To find the second derivative of the deflection, the unit is ; Calculate the value for the structural frequency.

7. The method for quickly acquiring the structural frequency of a pedestrian bridge according to claim 1, characterized in that: In step S5, the on-site measurement and sampling test of small samples are carried out to correct the sample library in step S4 to obtain a corrected sample library of geometric and material parameters-structural frequency of the pedestrian bridge. The specific correction formula is as follows: Where, is the frequency correction coefficient, which is obtained by fitting the deviation between the measured sample and the predicted value; is the calculated value of the structural frequency; is the corrected structural frequency.

8. A device for quickly acquiring the structural frequency of a pedestrian bridge, characterized in that: Includes the following modules: Parameter acquisition module, used to obtain geometric parameters and material parameters of the pedestrian bridge; Benchmark model building module, used to build the benchmark model of the pedestrian bridge under test based on geometric parameters and material parameters; The structural frequency calculation module is used to calculate the structural frequency of the pedestrian bridge based on the Benchmark model and the conversion relationship between kinetic energy and strain energy; A sample library establishment module is used to repeat the operations from the parameter acquisition module to the structural frequency calculation module to obtain multiple sets of samples and establish a pedestrian bridge geometry and material parameter-structural frequency sample library; The sample library correction module is used to carry out on-site measurement and sampling inspection of small samples, correct the sample library, and obtain the corrected sample library of geometric and material parameters-structure frequency of pedestrian bridges; The structural frequency estimation module is used to quickly estimate the structural frequency of pedestrian bridges through statistical analysis methods based on the pedestrian bridge geometry and material parameters-structural frequency correction sample library.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method for quickly acquiring the structural frequency of a pedestrian bridge according to any one of claims 1 to 7 are implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for quickly acquiring the structural frequency of a pedestrian bridge according to any one of claims 1 to 7 are implemented.

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