Bridge cable steel wire tension estimation method

Abstract

The invention relates to the technical field of bridge cables, and provides a bridge cable steel wire tension estimation method which comprises the steps of analyzing design frequency, measuring the actual length of a cable, collecting vibration intensity data, screening effective data segments and performing low-pass filtering, converting data, extracting first-order and second-order frequency, fitting a modal curve to verify validity and correcting the design frequency. Calculating frequency relative deviation, average frequency change rate and mass loss rate, analyzing equivalent linear density, fitting a modal curve, determining effective length, analyzing equivalent effective length, analyzing equivalent frequency, and finally estimating tension by combining the equivalent linear density, the equivalent effective length and the equivalent frequency. According to the method, the influence of corrosion on the linear density is corrected, and the first-order and second-order modal parameters are combined to cooperatively offset the deviation, so that the accuracy of bridge cable tension measurement is effectively guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bridge cable, in particular to a bridge cable steel wire tension estimation method. BACKGROUND

[0002] For small-sized movable bridges in daily life, the tension state of the cable steel wire as the main force structure supporting the bridge deck directly determines the structural safety of the whole bridge. During long-term service, the cable steel wire may be corroded due to high-salt high-humidity, air humidity and other environmental factors, and may also be relaxed due to continuous external force vibration, resulting in that the actual bearing tension gradually decreases below the design expected safety value. Therefore, it is necessary to regularly analyze the tension of the cable steel wire, quantify the actual force state, and determine whether the tension is within the safe range to ensure the safety of the bridge structure.

[0003] Chinese patent publication No. CN101532894B discloses an intelligent portable cable tension measuring instrument, which comprises a hydraulic jack for generating a cable tension measuring force, a bridge arm, a pressure sensor, a displacement sensor, and a microprocessor for measuring the cable tension according to the measurement data of the pressure sensor and the displacement sensor. The microprocessor comprises a data reading unit for reading the measurement data of the pressure sensor and the displacement sensor, a measured cable diameter estimation unit for estimating the diameter of the measured cable, a measured cable bending moment estimation unit for obtaining a measured cable bending moment curve with the diameter and deformation of the cable as variables by using an experimental method, and a cable tension measuring unit for calculating the tension of the cable according to the measurement data of the pressure sensor and the displacement sensor, the length of the bridge arm, and the measured cable bending moment data. The above-mentioned invention has a wide measurement range, high measurement accuracy, portability, and high intelligence.

[0004] After the cable steel wire is corroded in a corrosive environment, its own physical parameters will change, which will directly affect the parameters in the tension measurement process and further cause deviation in the measurement results. The existing technology often ignores the change in linear density caused by corrosion, so that the change in linear density is not corrected and the linear density parameter is distorted during estimation.

[0005] Therefore, the present application provides a bridge cable steel wire tension estimation method to solve the above problems. SUMMARY

[0006] The present application provides a bridge cable steel wire tension estimation method, which corrects the change in linear density caused by corrosion to solve the problem of distorted linear density parameter during estimation in the prior art.

[0007] The specific technical solutions of the present application are as follows:

[0008] A bridge cable steel wire tension estimation method, comprising the following steps:

[0009] S1, based on the design data of the cable, the design mass, the design linear density, the design tension and the design length of the cable are obtained, and the corrosion calibration data of the cable is obtained, and the design frequency of the cable is analyzed based on the design linear density, the design length and the design tension;

[0010] The present application is directed to a small-sized suspension bridge with simple structure, the length of such suspension bridge ranges from 20m to 50m, and an elongated steel wire rope such as high-strength galvanized steel wire rope is usually used as the main force cable, when a person walks on the suspension bridge, the main force cable will vibrate obviously; in the present application, the corrosion calibration data refers to the corresponding relationship database of the cable corrosion characterization quantity and the performance change quantity, which is mainly derived from the experimental data of the cable in the design stage; the corrosion calibration coefficient in the corrosion calibration data is mainly used to quantify the proportion of the cable performance change quantity and the corrosion degree;

[0011] S2, the actual length of the cable is measured, and the interference source is investigated;

[0012] In the present application, the cable will be affected by installation errors, service deformation, corrosion damage and other factors in actual engineering, so that the actual length deviates from the design length, and therefore the length needs to be measured again to reduce the error in subsequent calculation; the interference source refers to factors that may exist in the field scene and are easy to affect the vibration of the cable, such as environment, structure and equipment;

[0013] S3, a plurality of acceleration sensors are arranged along the axial direction of the cable, time and acceleration data of the cable are collected as vibration intensity data of the cable;

[0014] In the present application, at least 5-8 acceleration sensors need to be arranged along the axial direction of the cable, and are uniformly arranged away from the boundary effect zone of the cable, and the collection direction of the acceleration sensor is perpendicular to the axial direction of the cable;

[0015] S4, screening effective data segments in the vibration intensity data, low-pass filtering the effective data segments, and converting the processed vibration intensity data into frequency and amplitude data based on the frequency domain analysis method;

[0016] In the present application, screening the effective data segments refers to removing the initial impact interference and the end attenuation segment, and retaining the effective vibration segment with stable amplitude in the middle; the low-pass filtering processing refers to removing wind noise, equipment electronic noise and other high-frequency interference, and retaining useful low-frequency vibration of the cable; the frequency domain analysis method refers to fast Fourier transform, which is used to convert the acceleration data in the time domain into frequency amplitude data in the frequency domain;

[0017] S5, detecting the peak value in the frequency and amplitude data, and analyzing the first-order frequency and the second-order frequency of the cable based on the modal characteristics;

[0018] In the present application, the peak value can be detected by using the common tools in the prior art, such as MATLAB, LabVIEW, HEADAcoustics Artemis, etc. After inputting the frequency data and amplitude data, such tools can automatically identify the peak value, i.e. the position where the amplitude is higher than the surrounding points; the first-order frequency refers to the frequency corresponding to the peak value with the lowest frequency and the largest amplitude; the second-order frequency is near 2 times of the first-order frequency, and the peak value meeting the requirements in the frequency domain data can be found to determine the second-order frequency;

[0019] S6. Based on the first-order frequency and the second-order frequency, the vibration intensity data is band-pass filtered, the average amplitude of the filtered data is counted, the data pair of the cable axial position and the average amplitude is obtained, and the first-order modal curve and the second-order modal curve are fitted, and the effectiveness of the first-order and second-order frequencies is verified based on the inherent characteristics of the modal curve;

[0020] In the present application, the band-pass filtering refers to retaining the vibration signals of the first-order frequency and the second-order frequency, and filtering out the interference of other frequencies; the statistical average amplitude is used to obtain the stable amplitude value of each axial position, so as to form the data pair of the axial position and the average amplitude; when fitting, the common tools in the prior art, such as MATLAB and LabVIEW, are selected, the axial position is taken as the horizontal coordinate data, the average amplitude is taken as the vertical coordinate data, after being imported into the fitting tool, the first-order modal selects a half-sine wave model, the second-order modal selects a sine wave model, and automatic fitting is performed, so as to output the first-order modal curve and the second-order modal curve; the first-order modal curve is a half-sine wave, the amplitudes at both ends are approximately 0, and the amplitude in the middle is the largest; if the fitting curve is high in the middle and low at both ends, and there is only one wave peak, it indicates that the first-order frequency is correct; the second-order modal curve is a sine wave, the amplitudes at both ends are approximately 0, and there is one wave trough in the middle, and the wave peak is between both ends and the middle; if the fitting curve has one wave trough and two wave peaks, it conforms to a sine wave, which indicates that the second-order frequency is correct;

[0021] S7. The design frequency is corrected according to the actual length, the relative deviation of the first-order and second-order frequencies and the corrected design frequency is analyzed according to the corrosion calibration data of the cable, the mass loss rate of the cable is obtained, and the equivalent linear density of the cable is analyzed based on the mass loss rate and the design mass;

[0022] In the application, the design frequency is calculated based on the design length, and there is a certain error between the design length and the actual length, so the calculation result needs to be corrected;The relative deviation refers to the difference between the first-order and second-order frequency of the cable and the corrected design frequency, and the proportion of the corrected design frequency, which is used to quantify the deviation degree of the actual frequency and the theoretical frequency, and the principle is that cable corrosion will cause mass loss, and mass loss will directly cause vibration frequency change, specifically, the relative deviation of single-stage frequency is calculated first, and then the average frequency change rate is calculated;The mass loss rate refers to the proportion of the mass loss of the cable due to corrosion, wear and other factors to the design mass, the higher the mass loss rate, the more serious the corrosion, and the more obvious the decline of the cable carrying capacity;The equivalent linear density refers to the actual average mass per unit length of the cable considering the mass loss rate, which replaces the design linear density for subsequent tension calculation, and eliminates the influence of linear density deviation caused by corrosion on tension estimation;

[0023] S8, the first-order and second-order modal shape curves are fitted according to the sine function respectively, the intersection points of the fitted first-order curve, second-order curve and axial coordinate axis are determined to determine the first-order effective length and second-order effective length, and the first-order and second-order effective lengths and frequencies are combined to analyze the equivalent effective length of the first-order and second-order modes;

[0024] In the application, the first-order and second-order modal shape curves are approximate modal curves, which are fitted according to the sine function, so that the approximate modal curve can be corrected to a standard sine function, thereby establishing a standard model that can be solved mathematically;According to the string vibration theory, the intersection points of the fitting curve and the axial coordinate axis are essentially the node positions of cable vibration, and the effective length is the node spacing actually participating in the vibration of the cable;The equivalent effective length is the optimal comprehensive value obtained by combining the first-order and second-order effective lengths and frequencies, and the purpose is to balance the deviation of different modes;

[0025] S9, based on the first-order frequency and the second-order frequency, the equivalent frequency of the cable is analyzed;

[0026] In the application, the equivalent frequency is designed by the weight of the fourth power and the third power term, which preferentially adopts the second-order frequency with higher modal stability, while retaining the basic vibration information of the first-order frequency, and uses the stability of the second-order to offset the interference of the first-order;

[0027] S10, based on the equivalent linear density, equivalent effective length and equivalent frequency of the cable, the estimated tension of the cable is analyzed.

[0028] In the application, the estimated tension is based on the string vibration theory, and the actual parameters are corrected to replace the ideal design parameters, so as to eliminate the interference of multi-source error on the tension.

[0029] In a preferred technical solution, in step S1, the design frequency of the cable is analyzed based on the following formula:

[0030]

[0031] In the formula, n represents the modal order; L represents the design length of the cable; T represents the design tension of the cable; ρ represents the design linear density of the cable.

[0032] In a preferred technical solution, in the step S5, the modal characteristic is the frequency order relationship of the string vibration theory, which is represented by the following formula:

[0033]

[0034] In the formula, ω1 represents the first-order frequency.

[0035] In a preferred technical solution, in the step S7, the design frequency is corrected based on the following formula:

[0036]

[0037] In the formula, ωn represents the corrected n-th order design frequency; L represents the actual length of the cable.

[0038] In a preferred technical solution, in the step S7, the mass loss rate of the cable is analyzed based on the following formula:

[0039]

[0040] In the formula, ωn represents the relative deviation of the n-th order frequency and the corrected design frequency; the n-th order frequency change rate of the cable is ;

[0041]

[0042] In the formula, ρ represents the mass loss rate of the cable; α represents the corrosion calibration coefficient obtained from the corrosion calibration data of the cable; ω represents the average frequency change rate of the cable.

[0043] In the present application, the corrosion calibration coefficient is a proportional coefficient determined by experiment in the design stage of the cable, used to describe the quantitative relationship between the frequency change rate of the cable and the mass loss rate; further, for the cable lacking corrosion calibration data, the data can be obtained by accelerated corrosion experiment, specifically, a steel wire sample of the same material and specification as the cable can be selected, salt spray test, electrochemical corrosion, etc. are carried out, so that the sample produces different degrees of corrosion, the mass loss rate of each corrosion stage is measured, and the first-order and second-order frequencies of each corrosion stage are obtained. The relative deviation of the frequency from the uncorroded state is calculated, and then the mass loss rate and the relative deviation of the frequency are fitted to obtain the proportional relationship between the two, i.e. the corrosion calibration coefficient.

[0044] In the present application, the average frequency change rate refers to the arithmetic mean of the first-order frequency relative deviation and the second-order frequency relative deviation of the cable, which is used to integrate the change information of the two-order frequencies, reduce the error interference of the single-order frequency, and make the frequency change rate more reflect the mass loss of the cable as a whole.

[0045] In a preferred technical solution, in the step S7, the equivalent linear density of the cable is analyzed based on the following formula:

[0046]

[0047] In the formula, represents the equivalent linear density of the cable.

[0048] In a preferred technical solution, in the step S8, the basic form of the sine function is:

[0049]

[0050] In the formula, represents the fitting modal displacement of the n-th modal; represents the amplitude coefficient of the n-th modal; x represents the axial horizontal coordinate of the cable; represents the offset parameter of the n-th modal; represents the effective length of the n-th modal.

[0051] In the present application, the transverse vibration of the cable follows the string vibration theory, and the analytical solution of the partial differential equation is a sine function form. Because the cable has problems such as non-ideal boundary and length deviation, the effective length is used to replace the design length, the offset parameter is used to correct the boundary offset, and the amplitude coefficient is used to adapt the vibration intensity.

[0052] In a preferred technical solution, in the step S8, the equivalent effective length of the cable is analyzed based on the following formula:

[0053]

[0054] In the formula, Indicates the equivalent effective length; Indicates the effective length of the p-th mode; The effective length of the q-th mode is represented by p and q, where p is 1 and q is 2. This represents the frequency of the p-th mode; This represents the frequency of the q-th mode.

[0055] In this invention, the effective length of a single-order mode has a mode-specific error, and direct use can easily lead to serious distortion in tension estimation. It is necessary to compensate for the deviation by integrating multi-order data.

[0056] In a preferred embodiment, in step S9, the equivalent frequency of the cable is analyzed based on the following formula:

[0057]

[0058] In the formula, This indicates the equivalent frequency of the cable.

[0059] In this invention, the second-order frequency of the ideal string vibration is twice that of the first-order frequency. However, in actual cables, deviations may occur due to corrosion, boundary relaxation, and other reasons. Furthermore, the error sources for the first-order and second-order frequencies are different, so it is necessary to calculate the equivalent frequency to correct the deviation and offset the single-order deviation.

[0060] In a preferred embodiment, in step 10, the estimated tension of the cable is analyzed based on the following formula:

[0061]

[0062] In the formula, This indicates the estimated tension of the cable.

[0063] In this invention, when estimating tension based on string vibration theory, the equivalent linear density is used to eliminate mass loss caused by corrosion, the equivalent effective length is used to eliminate the deviation between the actual vibration length and the design length, the equivalent frequency is used to eliminate measurement errors of single-order frequencies, and the combined effect eliminates the superposition effect of multi-source errors.

[0064] Compared with the prior art, the present invention has the following beneficial effects:

[0065] 1. This invention is based on string vibration theory. It collects the vibration signal of the cable through an accelerometer, filters the effective data segments, eliminates interference by low-pass filtering, fits the first-order and second-order modal curves, and calculates the average frequency change rate by combining the corrosion calibration data of the cable. It then derives the mass loss rate of the cable to obtain the equivalent linear density. This invention solves the problem of existing technologies ignoring the influence of corrosion on linear density, which leads to an overestimation of the tension back-calculation value.

[0066] 2. The application utilizes the complementary principle of different order modal characteristics, balances the inherent defects of the first order modal being easily disturbed by wind noise and the second order modal being excessively sensitive to local defects through parameter coordination fusion, forms a multi-dimensional data cross verification mechanism, and solves the problem of low tension estimation accuracy of single order modal. BRIEF DESCRIPTION OF DRAWINGS

[0067] Fig. 1 is the overall flowchart of the application.

[0068] Fig. 2 is a schematic diagram of the first order frequency of the cable with different tensions changing with corrosion days.

[0069] Fig. 3 is a schematic diagram of the second order frequency of the cable with different tensions changing with corrosion days. DETAILED DESCRIPTION

[0070] The embodiments of the application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the application, but cannot be used to limit the scope of the application.

[0071] Example 1: As shown in the table, this embodiment takes a rural convenient suspension bridge as an example, with a main span of 20 m for pedestrian and electric vehicle traffic; the target cable is a 1x7 galvanized steel strand cable, which has been in service for 7 years and has yellow-brown rust on the surface. Figs. 1-3

[0072] In this embodiment, the design length of the cable is 21 m, the design linear density is 1.18 kg / m, the design tension is 4.0x10 5 N, and the corrosion calibration coefficient is 0.93.

[0073] The calculation of the design frequency can obtain the first order design frequency of about 13.86 Hz and the second order design frequency of about 27.72 Hz.

[0074] A laser range finder is used to measure the cable, and the actual length of the cable is measured to be 21.2 m by continuously measuring 3 times and taking the average value in a windless period.

[0075] After troubleshooting the on-site interference source, the test is carried out in the morning without wind and pedestrians.

[0076] Five PCB352C65 type acceleration sensors are selected, avoiding the 2m boundary effect zone at both ends, and the arrangement positions are 2m, 6m, 11m, 16m and 19m. The collection direction is perpendicular to the cable axis, and the time-acceleration data is synchronously collected through a data collector for 10 seconds.

[0077] The first 1 second impact section and the last 2 second decay section are removed, and the remaining 7 second stable data is obtained.

[0078] ​Low-pass filter is used to filter out high-frequency noise by Butterworth filter;

[0079] After FFT transformation, the amplitude peak value is detected, and the first-order frequency 14.0 Hz and the second-order frequency 28.1 Hz are extracted;

[0080] Based on the first-order and second-order frequencies, a band-pass filter is set, the average amplitude of each sensor position is counted, and the first-order modal curve (the amplitude at the midpoint 11 m is maximum 0.12 mm) and the second-order modal curve (the amplitude at 6 m and 16 m is maximum 0.09 mm) are fitted to confirm the effectiveness of the frequency.

[0081] The design frequency is corrected by substituting the data, and the corrected first-order design frequency is about 13.72 Hz, the corrected second-order design frequency is about 27.44 Hz, the relative deviation of the first-order frequency is about 0.0202, the relative deviation of the second-order frequency is about 0.0238, the average frequency change rate is about 0.022, and the mass loss rate is about 2.05%; by substituting the mass loss rate, the equivalent linear density is about 1.156 kg / m;

[0082] The first-order and second-order modal curves are fitted according to the sine function, the intersection points of the first-order curve and the coordinate axis are 1.9 m and 22.6 m, the effective length of the first-order is 20.7 m; the intersection points of the second-order curve and the coordinate axis are 1.7 m and 22.6 m, the effective length of the second-order is 20.9 m; by solving the equations, the equivalent effective length is about 20.8 m;

[0083] By substituting the first-order frequency and the second-order frequency, the equivalent frequency is calculated to be about 13.98 Hz;

[0084] Finally, the equivalent linear density, the equivalent effective length and the equivalent frequency are substituted to calculate the estimated tension, which is about 3.92×10 5 N, the deviation from the design tension is about 2%.

[0085] In this embodiment, the laser range finder is used to measure the cable, and the actual length of the cable is measured to be 21.2 m by continuously measuring 3 times without wind and taking the average value;

[0086] In this embodiment, the laser range finder is used to measure the cable, and the actual length of the cable is measured to be 21.2 m by continuously measuring 3 times without wind and taking the average value;

[0087] After FFT transformation, the amplitude peak value is detected, and the first-order frequency 14.41 Hz and the second-order frequency 29.02 Hz are extracted;

[0088] Based on first-order, second-order frequency setting band-pass filter, the average amplitude of each sensor position is counted, the first-order modal curve (the midpoint 11m amplitude maximum 0.15mm) and the second-order modal curve (6m, 16m position amplitude maximum 0.12mm) are fitted, and the effectiveness of the frequency is confirmed.

[0089] The data is substituted to correct the design frequency, the corrected first-order design frequency is about 13.72Hz, the corrected second-order design frequency is about 27.44Hz, the relative deviation of the first-order frequency is about 0.05, the relative deviation of the second-order frequency is about 0.0576, then the average frequency change rate is about 0.0538, the mass loss rate is about 5.0% calculated, the equivalent linear density is about 1.121kg / m calculated by substituting the mass loss rate;

[0090] The first-order and second-order modal curves are fitted according to the sine function, the intersection points of the first-order curve and the coordinate axis are 1.9m and 22.5m, the first-order effective length is 20.6m; the intersection points of the second-order curve and the coordinate axis are 1.8m and 22.5m, the second-order effective length is 20.7m; the equivalent effective length is about 20.65m calculated by combination;

[0091] The first-order frequency and the second-order frequency are substituted, the equivalent frequency is about 14.38Hz calculated;

[0092] Finally, the equivalent linear density, the equivalent effective length and the equivalent frequency are substituted to calculate, the estimated tension is about 3.80*10 5 N, the deviation compared with the design tension is about 5%.

[0093] The embodiments of the application are given for example and description, although the embodiments of the application have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary, and cannot be understood as the limitation of the application, the ordinary skilled in the art can change, modify, replace and modify the above-mentioned embodiments within the scope of the application.

Claims

1. A method for estimating the tension of steel wires in bridge cables, characterized in that, Includes the following steps: S1. Based on the cable design data, obtain the cable design quality, design linear density, design tension and design length, as well as the cable corrosion calibration data, and analyze the cable design frequency based on the design linear density, design length and design tension. S2. Measure the actual length of the cable and identify the source of interference; S3. Arrange several acceleration sensors along the cable axis to collect the time and acceleration data of the cable, which will be used as the vibration intensity data of the cable. S4. Filter the effective data segments in the vibration intensity data, process the effective data segments with low-pass filtering, and convert the processed vibration intensity data into frequency and amplitude data based on the frequency domain analysis method. S5. Detect peak values ​​in frequency and amplitude data, and analyze the first and second order frequencies of the cable based on modal characteristics; S6. Based on the first-order and second-order frequencies, bandpass filtering is applied to the vibration intensity data. The average amplitude of the filtered data is statistically analyzed to obtain the data pair between the cable axial position and the average amplitude. The data is then fitted into first-order and second-order modal curves. The effectiveness of the first-order and second-order frequencies is verified based on the inherent characteristics of the modal curves. S7. Correct the design frequency according to the actual length. Based on the corrosion calibration data of the cable, analyze the relative deviation between the first-order and second-order frequencies and the corrected design frequency to obtain the mass loss rate of the cable. Based on the mass loss rate and the design mass, analyze the equivalent linear density of the cable. S8. Fit the shape curves of the first and second modes with sine functions respectively. Based on the intersection points of the fitted first and second curves with the axial coordinate axes, determine the first and second effective lengths. Combine the first and second effective lengths with the frequency to analyze the equivalent effective lengths of the first and second modes. S9. Analyze the equivalent frequency of the cable based on the first-order and second-order frequencies. S10. Based on the cable's equivalent linear density, equivalent effective length, and equivalent frequency, analyze the estimated tension of the cable.

2. The method for estimating the tension of bridge cable wires according to claim 1, characterized in that, In step S1, the design frequency of the cable is analyzed based on the following formula: In the formula, This represents the nth design frequency; n represents the modal order. Indicates the design length of the cable; Indicates the design tension of the cable; This indicates the design linear density of the cable.

3. The method for estimating the tension of bridge cable wires according to claim 1, characterized in that, In step S5, the modal characteristics are related to the frequency order in string vibration theory, expressed by the following formula: In the formula, It represents the first-order frequency.

4. The method for estimating the tension of bridge cable wires according to claim 1, characterized in that, In step S7, the design frequency is corrected based on the following formula: In the formula, This represents the nth-order design frequency after correction; This indicates the actual length of the cable.

5. The method for estimating the tension of bridge cable wires according to claim 1, characterized in that, In step S7, the cable mass loss rate is analyzed based on the following formula: In the formula, This represents the relative deviation between the nth-order frequency and the corrected design frequency; the rate of change of the nth-order frequency of the cable is... ; In the formula, This indicates the cable's mass loss rate; This represents the corrosion calibration coefficient obtained from the corrosion calibration data of the cable; This represents the average frequency change rate of the cable.

6. The method for estimating the tension of bridge cable wires according to claim 1, characterized in that, In step S7, the equivalent linear density of the cable is analyzed based on the following formula: In the formula, This represents the equivalent linear density of the cable.

7. The method for estimating the tension of bridge cable wires according to claim 1, characterized in that, In step S8, the basic form of the sine function is: In the formula, This represents the fitted modal displacement of the nth order mode; represents the amplitude coefficient of the nth mode; x represents the axial horizontal coordinate of the cable; The offset parameter represents the nth mode; This represents the effective length of the nth mode.

8. The method for estimating the tension of bridge cable wires according to claim 1, characterized in that, In step S8, the equivalent effective length of the cable is analyzed based on the following formula: In the formula, Indicates the equivalent effective length; Indicates the effective length of the p-th mode; The effective length of the q-th mode is represented by p and q, where p is 1 and q is 2. This represents the frequency of the p-th mode; This represents the frequency of the q-th mode.

9. The method for estimating the tension of bridge cable wires according to claim 1, characterized in that, In step S9, the equivalent frequency of the cable is analyzed based on the following formula: In the formula, This indicates the equivalent frequency of the cable.

10. The method for estimating the tension of bridge cable wires according to claim 1, characterized in that, In step 10, the estimated tension of the cable is analyzed based on the following formula: In the formula, This indicates the estimated tension of the cable.

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