A method for intelligent monitoring of cable force of a stay cable based on bending wave transmission speed

Abstract

This invention discloses an intelligent monitoring method for cable-stayed bridge force based on the propagation velocity of bending waves. The method includes: deriving the theoretical relationship between the propagation velocity of bending waves and the cable axial force, cable density, and cross-sectional area; before actual deployment, estimating the magnitude of the theoretical propagation velocity of bending waves, and setting a reasonable lower limit for the distance between the impact point of the vibration excitation device and the piezoelectric sensor, taking into account the time resolution and upper limit of the allowable error of the high-frequency signal acquisition instrument; during actual identification, using the vibration excitation device to laterally impact the cable at a set position to excite bending waves, and acquiring the wave response signal, performing time-frequency demodulation to accurately identify the actual propagation velocity of the bending wave within the reasonable distance; finally, directly analyzing and inverting the theoretical relationship to obtain the real-time cable force of the cable-stayed bridge. This invention effectively overcomes the shortcomings of traditional frequency methods that overly rely on boundary conditions, cable length, and sag effects, and has the advantages of being non-destructive, fast, having a clear identification mechanism, and being easy to operate.

Description

Technical Field

[0001] This invention belongs to the field of engineering structure health monitoring data analysis technology, specifically relating to an intelligent monitoring method for cable force based on bending wave propagation velocity. Background Technology

[0002] As the main load-bearing components of structures such as long-span bridges, stay cables in engineering structures bear enormous axial tensile forces, and the magnitude of their cable force is an important indicator for evaluating the overall bridge performance and structural safety. Developing efficient, rapid, and high-precision methods for real-time monitoring of stay cable force is a fundamental task for ensuring the safe operation of infrastructure.

[0003] Existing methods for detecting cable tension in cable-stayed structures primarily employ the frequency method, which measures the fundamental frequency and various modes of cable vibration and uses the mapping relationship between frequency and cable force to assess the cable force. However, the traditional frequency method suffers from the following key drawbacks in practical applications: 1. The analysis results rely excessively on the boundary conditions, effective cable length, and sag effect of the cables, making them difficult to accurately calibrate under actual complex boundary conditions; 2. For cable systems of varying lengths and parameters, the universal formula of the frequency method often requires cumbersome modifications. 3. When the random excitation signal in the environment is weak, the fundamental frequency identification is easily affected by the noise from bridge traffic and strong winds, which affects the identification accuracy. Summary of the Invention

[0004] To address at least one of the problems in existing technologies, such as over-reliance on boundary conditions, significant environmental noise interference, and difficulty in correcting for cable length discrepancies, this invention provides an intelligent monitoring method for cable force based on the propagation velocity of bending waves. This method simplifies the cable to a pure tensioned string dynamic model, establishes a direct analytical relationship between the theoretical propagation velocity of bending waves without dispersion and the cable axial force, and scientifically sets the distance measurement based on the time resolution of a high-frequency acquisition instrument. Wavelet transform is then used to accurately identify the wave velocity and directly invert the cable force. Its main features include: 1) Based on a tensioned string dynamic model, the cross-sectional stiffness is entirely provided by the cable force, and the bending wave velocity is independent of frequency, eliminating complex dispersion interference; 2) A scientific method for setting the impact point-sensor spacing based on the accuracy and error tolerance limit of the high-frequency signal acquisition instrument is proposed, controlling the relative measurement error from a physical mechanism perspective; 3) It is simple and convenient, achieving real-time non-destructive monitoring of cable force without the need for cumbersome boundary condition corrections or expensive full-body load tests.

[0005] To achieve the objective of this invention, the present invention provides an intelligent monitoring method for cable tension based on bending wave propagation velocity, comprising the following steps: Step 1: Based on the tensioned string dynamic model, establish the transverse vibration wave equation of the cable and derive the theoretical relationship between the bending wave transmission velocity and the cable axial force, cable density and cross-sectional area. Step 2: Obtain the design data or conventional cable force range, cable density and cross-sectional area of ​​the stay cable, and preliminarily calculate the magnitude of the theoretical transmission speed of the bending wave based on the theoretical calculation formula; Step 3: Based on the time acquisition accuracy of the high-frequency signal acquisition instrument and the order of magnitude of the theoretical transmission speed, calculate and set the lower limit of the reasonable distance between the impact point of the vibration excitation device and the piezoelectric sensor, and then deploy the vibration excitation device and the piezoelectric sensor on the cable-stayed bridge. Step 4: Use the vibration excitation device to laterally impact the cable body at a set position to excite bending waves, and synchronously collect the elastic wave response signal in the cable body through a piezoelectric sensor and a high-frequency signal acquisition instrument. Step 5: Use wavelet transform algorithm to demodulate the collected elastic wave response signal in time and frequency to accurately identify the actual propagation speed of the bending propagation wave within the reasonable spacing; Step 6: Using the theoretical relationship described in Step 1, calculate the real-time cable force of the cable based on the actual propagation speed identified in Step 5.

[0006] Furthermore, the piezoelectric sensor is connected to a high-frequency signal acquisition instrument to acquire elastic wave signals in the cable-stayed bridge.

[0007] Furthermore, the equation for the transverse vibration wave of the tensioned string established in step 1 is as follows:

[0008] in, It is the lateral displacement of the cable. For the axial force of the stay cable, For the density of the cable material, Let the cross-sectional area of ​​the cable be... Let x be the x-coordinate of the position under discussion along the cable axis. For time; Furthermore, the theoretical relationship between the bending wave propagation velocity and the cable axial force, cable density, and cross-sectional area is as follows:

[0009] In the formula, c The theoretical propagation speed of the bending wave is uniquely determined by the current cable axial force, cable material density, and cross-sectional area, and remains constant across the entire frequency band, independent of the bending wave frequency.

[0010] Furthermore, the preliminary calculation of the magnitude of the theoretical transmission speed of bending waves in step 2 specifically involves substituting the empirical magnitude of the design cable force or conventional cable force of the stay cable as known tension into the theoretical formula, and combining this with the material density and cross-sectional area to calculate an estimated reference value for the theoretical transmission speed of bending waves. c 0.

[0011] Furthermore, step 3, setting a reasonable distance between the impact point of the vibration excitation device and the piezoelectric sensor, specifically includes the following steps: Step 31: Obtain the sampling frequency of the high-frequency signal acquisition instrument. f s Determine the temporal resolution of its single sampling. ; Step 32: Set the upper limit of the allowable relative measurement error according to the engineering monitoring accuracy requirements. ; Step 33: Based on the estimated reference value c 0. Time resolution Upper limit of relative measurement error Through the formula:

[0012] The theoretical lower limit of the reasonable spacing was calculated. ; Step 34: Set the appropriate distance between the impact point and the piezoelectric sensor during actual deployment. L satisfy This is to control the relative error in time acquisition caused by excessively small spacing.

[0013] Furthermore, step 5, which uses wavelet transform algorithm to accurately identify the actual propagation speed, includes the following steps: performing continuous wavelet transform on the received elastic wave response signal to obtain a time-frequency energy spectrum, and extracting the arrival time corresponding to the maximum energy value of the bending wave packet from the spectrum. Combined with the impact triggering time of the vibration excitation device The actual propagation time of the flexural wave in the cable was calculated. Finally, based on the known reasonable spacing... L The actual propagation speed is calculated. .

[0014] Furthermore, the reasonable spacing is also expressed as the axial distance between two piezoelectric sensors arranged at a fixed interval along the cable axis; the actual propagation speed is obtained by calculating the ratio of the time difference between the arrival of the bending wave packet at the two piezoelectric sensors to the axial distance.

[0015] Furthermore, the piezoelectric sensor is installed on the cable by surface bonding or embedded method. When a single sensor is damaged, it can be directly replaced with a sensor of the same model. After replacement, the entire cable force recognition system does not need to be recalibrated.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention is based on the relationship derived from the tensioned string dynamics model, which makes the propagation speed of bending waves uniquely determined by the cable axial force, cable density, and cross-sectional area. Since the wave propagates inside the cable, its speed is not affected by the complex anchorage boundary conditions at both ends, cable length, and sag, and directly reflects the local stress state of the cable.

[0017] 2. This invention is the first to combine the time resolution of a high-frequency signal acquisition instrument with the expected wave velocity, scientifically deriving the theoretical lower limit of the physical distance between the impact point and the sensor. Through precise hardware deployment, it effectively avoids the problem of excessive relative error in system acquisition caused by excessively small time differences.

[0018] 3. This invention combines the high-resolution time-frequency characteristics of wavelet transform, which can accurately locate the characteristic time of the transient bending wave packet excited by the impact from the messy low-frequency background noise of the engineering site. The inversion algorithm is a direct analytical calculation, which is extremely efficient and is very suitable for long-term real-time dynamic online monitoring. Attached Figure Description

[0019] Figure 1 A diagram illustrating the dynamic theoretical model of a tensioned string subjected to lateral impact, established for an embodiment of the present invention; Figure 2 This is a schematic diagram showing the arrangement of measuring points and load impact points on the cable-stayed model in an embodiment of the present invention; Figure 3 This is a diagram showing the actual propagation time of the elastic wave after continuous wavelet transform in an embodiment of the present invention. Figure 4 This is a flowchart of an intelligent monitoring method for cable force based on bending wave propagation velocity proposed in an embodiment of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] An embodiment of the present invention provides an intelligent monitoring method for cable force of a cable-stayed bridge based on the transmission velocity of bending waves. The specific steps mainly include deriving the theoretical relationship between bending wave velocity and cable force based on the tensioned string dynamic model, scientifically setting a reasonable spacing between measuring points in combination with the acquisition accuracy and wave velocity magnitude, lateral impact excitation and synchronous high-frequency acquisition of elastic wave signals, and using wavelet transform to accurately identify the actual wave velocity and analyze and invert the real-time cable force. The principle of this invention is as follows: Through theoretical analysis and error control mechanism research, it was found that when the time resolution of the high-frequency signal acquisition instrument is too small in physical distance measurement, it will have a significant relative error impact on the accuracy of transient wave velocity measurement. By utilizing the quantitative correspondence between the wave velocity magnitude estimated based on design data and the time resolution, the physical distance between the impact point of the vibration excitation device and the piezoelectric sensor is scientifically and rationally set. This eliminates the impact of excessive relative error in time acquisition from the mechanism stage during the hardware deployment phase, and achieves accurate acquisition of the propagation time of bending waves. Based on the derivation of the tensioned string dynamic model without considering bending stiffness, and utilizing the physical characteristic that the theoretical transmission speed of bending waves is uniquely determined only by the cable axial force, material density, and cross-sectional area and has no dispersion, the measured wave velocity is extracted with high precision through wavelet transform and directly analyzed and inverted using the formula. Finally, the dynamic evolution process of the cable force of the cable is monitored non-destructively, in real time, and with high precision.

[0022] Specifically, such as Figure 4 As shown in the figure, a method for intelligent monitoring of cable tension based on bending wave propagation velocity according to an embodiment of the present invention includes the following specific steps: Step 1: Based on the dynamic model of a tensioned string that does not consider bending stiffness, Figure 1 As shown, the stay cable is equivalent to a tensioned string with both ends restricted. Based on the force equilibrium condition of the stay cable's infinitesimal element, the partial differential equation of the wave under the action of small-amplitude lateral vibration of the stay cable is established, namely the wave equation of the lateral vibration of the stay cable. The theoretical relationship between the propagation speed of the non-dispersion bending wave and the cable axial force, cable density and cross-sectional area is derived. Figure 1 middle The position applied to the vibration excitation device Lateral impact, the impact over time change; This represents the self-weight load experienced by the infinitesimal element of the cable-stayed bridge.

[0023] The equation for the transverse vibration wave of the cable-stayed bridge is:

[0024] in, The density of the cable-stayed bridge material. The cross-sectional area of ​​the cable is... It is the lateral displacement of the stay cable. For time, For the axial force of the stay cable, The x-coordinate represents the position under discussion along the cable axis; By incorporating a simple harmonic wave solution into the equation for the transverse vibration of the cable-stayed bridge, the theoretical propagation velocity of a one-dimensional bending wave in the cable-stayed bridge is derived. With cable axial force The direct analytical quantitative relationship between them, and the theoretical relationship between the bending wave propagation velocity and the cable axial force, cable density, and cross-sectional area are as follows:

[0025] As can be seen from this formula, under a purely tensioned string boundary, the propagation speed of the bending elastic wave in the cable exhibits non-dispersion characteristics, that is, the magnitude of the speed is completely independent of the wave frequency and is uniquely determined by the cable axial force, material density and cross-sectional area.

[0026] Step 2: Obtain the design data of the completed bridge or a reasonable empirical range of the cable force of conventional cable stays for the bridge to be monitored, and set the current expected cable force value as [value missing]. Simultaneously, the material density of the cable of this specification was collected. and cross-sectional area Substituting the above parameters into the formula derived in step 1, a reference value of the magnitude of the bending wave propagation velocity inside the cable is estimated through calculation. .

[0027] Step 3: Combining the time acquisition accuracy of the high-frequency signal acquisition instrument with the reference value of the theoretical transmission speed, calculate and set the lower limit of the reasonable distance between the impact point of the vibration excitation device and the piezoelectric sensor. Based on this, deploy the vibration excitation device and piezoelectric sensor on the cable-stayed bridge. Figure 2 As shown. Among them, The position applied to the vibration excitation device Lateral impact, the impact over time change; This refers to the appropriate spacing between the vibration excitation device and the piezoelectric sensor, or between adjacent piezoelectric sensors.

[0028] Given the inherent fixed time resolution error in high-frequency signal acquisition instruments, if the physical ranging setting is too small and the propagation time difference is extremely short, the time resolution error of a single pulse in the high-frequency signal acquisition instrument will introduce a significant relative error into the wave velocity identification result. Therefore, this invention scientifically designs the spacing between measurement points: firstly, the sampling frequency of the high-frequency signal acquisition instrument is obtained. The temporal resolution of a single sampling was obtained. Next, based on the engineering accuracy specifications, input the upper limit of the permissible relative measurement error. (In one embodiment, setting) The order of magnitude of the flexural wave propagation velocity obtained in step 2 is used as a reference value. Time resolution Upper limit of relative measurement error Substituting into the formula, the theoretical lower limit of the reasonable spacing is obtained. :

[0029] During actual on-site installation, adjust and ensure the axial distance between the transverse impact point of the vibration excitation device and the measuring point of the piezoelectric sensor (or the axial distance between two adjacent piezoelectric sensors installed at a fixed interval). Figure 2 The reasonable spacing shown Strictly meet The technical conditions are designed to control the relative time acquisition error caused by excessively small spacing, thereby completely eliminating the risk of the system's relative acquisition error exceeding the limit at the hardware level.

[0030] In one embodiment, when the reasonable spacing is the axial distance between two piezoelectric sensors arranged at a fixed interval along the cable axis, the actual propagation speed is obtained by calculating the ratio of the time difference between the arrival of the bending wave packet at the two piezoelectric sensors to the axial distance.

[0031] Step 4: The vibration excitation device is used to laterally impact the cable body at a set position to excite bending waves, and the elastic wave response signal in the cable body is synchronously collected by a piezoelectric sensor and a high-frequency signal acquisition instrument.

[0032] The piezoelectric sensor is attached to the designated measuring point of the cable-stayed bridge using high-strength adhesive (or embedded during manufacturing). The signal output terminal of the piezoelectric sensor is connected to a high-frequency signal acquisition instrument via a shielded cable. After the system is turned on, a vibration excitation device (such as a hammer) is used at the appropriate interval set in step 3. At a point perpendicular to the cable axis, a transient transverse impact load is applied to the cable body, exciting a one-dimensional bending elastic wave that propagates long axially within the cable body. The high-frequency signal acquisition instrument uses a sampling frequency... The system synchronously and at high speed captures the fluctuation response at the piezoelectric sensor and records the complete electrical signal time history curve.

[0033] In one embodiment, when a single piezoelectric sensor malfunctions, it can be directly replaced with a sensor of the same model, and the entire cable force recognition system does not need to be recalibrated after the replacement.

[0034] In one embodiment, the impact direction is perpendicular to the long axis of the cable, and the instantaneous impact energy of the vibration excitation device must ensure that the amplitude of the excited bending wave signal, after propagating through a reasonable distance, is still more than 10dB higher than the background ambient noise.

[0035] Step 5: Demodulate the collected elastic wave response signal in time and frequency to accurately identify the actual propagation speed of the bending wave within a reasonable distance.

[0036] The acquired raw wave history signal exhibits significant baseline fluctuations due to interference from low-frequency clutter such as bridge surface vibration and wind load. In one embodiment, the continuous wavelet transform (CWT) algorithm is used to perform high-resolution time-frequency domain demodulation on this time history signal, generating an energy spectrum in the time-frequency domain, such as... Figure 3 As shown, the bending wave packet signal excited by transverse impact exhibits a distinct energy concentration band in the time-frequency energy spectrum. The time corresponding to the maximum value of the wavelet coefficient modulus is extracted as the wave packet arrival time. Combined with the impact triggering time of the vibration excitation device The actual propagation time of the flexural wave in the cable was calculated. Finally, based on the known reasonable spacing... The actual propagation speed is calculated. .

[0037] Step 6: Using the theoretical relationship from Step 1, calculate the real-time cable force of the cable based on the actual propagation speed identified in Step 5.

[0038] The actual propagation speed identified with high precision in step 5 Substitute these equations into the theoretical relationship from step 1. Since the model does not contain complex implicit dispersion terms, no complex optimization iterative algorithm is needed. The axial force of the stay cable can be directly calculated by inverse inversion using the univariate quadratic analytical formula. :

[0039] The method provided in the foregoing embodiments of this invention, before actual deployment, estimates the magnitude of the theoretical propagation speed of bending waves based on design data or conventional cable force prediction. Combined with the time resolution and upper limit of the allowable error of the high-frequency signal acquisition instrument, a reasonable lower limit for the distance between the impact point of the vibration excitation device and the piezoelectric sensor is scientifically set. This avoids the problem of excessive relative error in time acquisition caused by excessively small distances. During actual identification, the vibration excitation device laterally impacts the cable at a set position to excite bending waves. The piezoelectric sensor collects the wave response signal, and time-frequency demodulation is performed using a wavelet transform algorithm to accurately identify the actual propagation speed of the bending wave within the reasonable distance. Finally, the real-time cable force of the stay cable is obtained by direct analytical inversion using the theoretical relationship. This method overcomes the shortcomings of traditional frequency methods that over-rely on boundary conditions, cable length, and sag effects. It has the advantages of being non-destructive, fast, having a clear identification mechanism, and being easy to operate. It can be widely applied to the intelligent identification and health monitoring of the cable force of stay cables throughout their entire life cycle in civil engineering.

[0040] In one embodiment, a smart monitoring system for cable tension based on bending wave propagation velocity is provided. The system includes a vibration excitation device, a piezoelectric sensor, a high-frequency signal acquisition instrument, and a data processing module. The piezoelectric sensor is fixedly installed at the measuring point of the cable, and its signal output terminal is connected to the signal input terminal of the high-frequency signal acquisition instrument. A reasonable distance is maintained between the vibration excitation device and the piezoelectric sensor. The vibration excitation device is used to laterally impact the cable to excite bending waves. The high-frequency signal acquisition instrument is used to transmit the acquired elastic wave response signal to the data processing module, which then performs steps 5 and 6 of the method described in the aforementioned embodiment.

[0041] In one embodiment, the data processing module integrates a continuous streaming computing unit, which triggers the vibration excitation device to automatically impact within a preset time period (e.g., once every 5 seconds). The software performs rolling streaming processing on the incoming data stream, automatically outputs it online, and plots the trend curve of the cable force of the stay cable over time in real time on a large screen display terminal, thus fully realizing non-destructive, high-precision, and intelligent health monitoring of the cable force of the bridge stay cable throughout its entire life cycle.

[0042] In one embodiment, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program that, when executed by a processor, implements steps 5 and 6 of the method described in the foregoing embodiments.

[0043] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for intelligent monitoring of cable force in a stay cable based on bending wave propagation velocity, characterized in that, Includes the following steps: Step 1: Based on the tensioned string dynamic model, establish the transverse vibration wave equation of the cable and derive the theoretical relationship between the bending wave transmission velocity and the cable axial force, cable density and cross-sectional area. Step 2: Obtain the design data of the cable stay or the range of conventional cable force, cable density and cross-sectional area, and preliminarily calculate the magnitude of the theoretical transmission speed of bending waves based on the theoretical calculation formula; Step 3: Combining the time acquisition accuracy of the high-frequency signal acquisition instrument with the order of magnitude of the theoretical transmission speed, calculate and set the lower limit of the reasonable distance between the impact point of the vibration excitation device and the piezoelectric sensor, and then deploy the vibration excitation device and the piezoelectric sensor on the cable-stayed bridge accordingly. Step 4: Use the vibration excitation device to laterally impact the cable body at a set position to excite bending waves, and synchronously collect the elastic wave response signal in the cable body through a piezoelectric sensor and a high-frequency signal acquisition instrument. Step 5: Use wavelet transform algorithm to demodulate the collected elastic wave response signal in time and frequency, and identify the actual propagation speed of the bending wave within a reasonable distance. Step 6: Using the theoretical relationship described in Step 1, calculate the real-time cable force of the cable based on the actual propagation speed identified in Step 5.

2. The intelligent monitoring method for cable force of a stay cable based on bending wave propagation velocity according to claim 1, characterized in that, In step 1, the equation for the transverse vibration wave of the stay cable is: in, The density of the cable-stayed bridge material. The cross-sectional area of ​​the cable is... It is the lateral displacement of the stay cable. For time, For the axial force of the stay cable, The x-coordinate of the discussed position along the cable axis; or The theoretical relationship between the flexural wave propagation velocity and the cable axial force, cable density, and cross-sectional area is as follows: In the formula, This represents the theoretical propagation speed of a flexed wave under a tensioned string dynamic model.

3. The intelligent monitoring method for cable tension based on bending wave propagation velocity according to claim 1, characterized in that, In step 2, the preliminary estimation of the order of magnitude of the theoretical propagation speed of the bent wave is as follows: By substituting the empirical magnitude of the design cable force or conventional cable force of a stay cable into the theoretical formula as a known tension, and combining it with the material density and cross-sectional area, a reference value of the magnitude of the theoretical transmission velocity of bending waves can be calculated.

4. The intelligent monitoring method for cable force of a stay cable based on bending wave propagation velocity according to claim 1, characterized in that, Step 3, setting the appropriate distance between the impact point of the vibration excitation device and the piezoelectric sensor, specifically includes the following steps: Obtain the sampling frequency of the high-frequency signal acquisition instrument and determine the time resolution of a single sampling. The upper limit of the permissible relative measurement error is set according to the accuracy requirements of engineering monitoring; Based on the magnitude reference value, time resolution, and upper limit of relative measurement error, the theoretical lower limit of a reasonable spacing is calculated. Set a reasonable distance between the impact point and the piezoelectric sensor during actual deployment. satisfy This is to control the relative error in time acquisition caused by excessively small spacing. This represents the theoretical lower limit of a reasonable spacing.

5. The intelligent monitoring method for cable force of a stay cable based on bending wave propagation velocity according to claim 1, characterized in that, Step 5 involves using the wavelet transform algorithm to accurately identify the actual propagation speed, including the following steps: The received elastic wave response signal is subjected to continuous wavelet transform to obtain a time-frequency energy spectrum. The arrival time corresponding to the maximum energy value of the bending wave packet is extracted from the time-frequency energy spectrum. Combined with the impact triggering time of the vibration excitation device, the actual propagation time of the bending wave in the cable is calculated. Based on the actual propagation time, the actual propagation speed is obtained by conversion according to the known reasonable spacing.

6. The intelligent monitoring method for cable force of a stay cable based on bending wave propagation velocity according to claim 1, characterized in that: Reasonable spacing is also reflected in the axial distance between adjacent piezoelectric sensors arranged at fixed intervals along the cable axis; the actual propagation speed is obtained by calculating the ratio of the time difference between the arrival of the bending wave packet at the two piezoelectric sensors to the axial distance.

7. A method for intelligent monitoring of cable tension based on bending wave propagation velocity according to any one of claims 1-6, characterized in that, When the vibration excitation device is used to transversely impact the cable in step 4, the impact direction is perpendicular to the long axis of the cable. The instantaneous impact energy of the vibration excitation device must ensure that the amplitude of the excited bending wave signal is still higher than the preset background noise after propagating through a reasonable distance.

8. A system for intelligent monitoring of cable tension based on bending wave propagation velocity, characterized in that, It includes a vibration excitation device, a piezoelectric sensor, a high-frequency signal acquisition instrument, and a data processing module; The piezoelectric sensor is fixedly installed at the measuring point of the cable-stayed bridge, and the signal output terminal of the piezoelectric sensor is connected to the signal input terminal of the high-frequency signal acquisition instrument. The vibration excitation device and the piezoelectric sensor maintain a reasonable distance, and the vibration excitation device is used to laterally impact the cable to excite bending waves. The high-frequency signal acquisition instrument is used to transmit the acquired elastic wave response signal to the data processing module, and the data processing module executes steps 5 and 6 of the method according to any one of claims 1-7.

9. The system according to claim 8, characterized in that: The data processing module integrates a continuous streaming computing unit. The vibration excitation device automatically excites the cable body with lateral impact according to a preset time period. The data processing module performs rolling real-time calculations on the data stream input from the high-frequency signal acquisition instrument, outputs online and plots the trend curve of the cable force dynamic evolution over time in real time.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements steps 5 and 6 of the method according to any one of claims 1-7.

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