A method and system for analyzing the fullness of a borehole grout

Abstract

The present application relates to the technical field of material testing analysis, in particular to a hole grouting fullness analysis method and system; the analysis method applies a wideband excitation to the hole grouting member, so that the excitation frequency band covers the natural vibration frequency of the hole grouting member cavity defect, thereby causing the cavity defect resonance. The hole grouting fullness is detected by directly detecting the resonance wave signal emitted by the cavity defect resonance. The method directly uses the cavity defect as the seismic source and directly detects the resonance signal excited from the cavity defect to the surface of the member; compared with the traditional impact echo method which uses an impact hammer as the seismic source and detects the echo signal reflected back after the impact wave is excited from the surface of the member and meets the internal cavity defect, the propagation path of the resonance signal detected by the present method is only half of the propagation path of the impact echo, the resonance signal attenuation is small, the detection depth is deeper, the interference is less, the accuracy of the obtained resonance spectrum is higher, and finally the hole grouting fullness analysis accuracy is improved.

Description

Technical Field

[0001] This invention relates to the field of materials testing and analysis technology, and in particular to a method and system for analyzing the fullness of grout filling in ducts. Background Technology

[0002] During the manufacturing process of bridge ducts, insufficient grouting fullness can easily lead to voids within the duct components. Therefore, detecting the grouting fullness of prestressed bridge ducts is a key technical challenge in the field of bridge engineering material testing and analysis. Although various testing methods have been developed in the industry, their practical applications are significantly limited due to the inherent characteristics of their different technical principles. For example, the impact-echo method has some detection capability for internal defects in large-sized metal corrugated pipes, but it is prone to missed or false detections in areas with dense reinforcement, and its accuracy decreases with the depth of the defect.

[0003] The existing impact-echo method is an echo-based detection technique. This method uses a handheld impact hammer to strike the surface of a component, generating longitudinal waves. The echo characteristics of these mechanical longitudinal waves reflected within the component are then used to identify internal voids and defects. This method has some detection capability for larger voids or segregation defects in corrugated metal pipes, but its resolution and sensitivity are limited by the diameter of the impact hammer: ordinary impact hammers can only generate longitudinal waves of a single frequency, and different hammer diameters produce longitudinal waves with different wavelengths. Furthermore, there is a lack of methods for selecting a suitable impact hammer size when the size and depth of the defect are unknown. In areas with dense reinforcement, the longitudinal waves, incident from the component surface, are reflected by internal defects, resulting in a propagation path length twice the depth of the defect. This leads to significant signal attenuation and increased susceptibility to interference, such as wavefront distortion caused by the difference in wave velocity between the reinforcement and concrete, scattering effects from dense reinforcement mesh, and coupled vibration interference from the corrugated metal pipe. These factors can easily lead to missed or false detections.

[0004] Therefore, how to optimize the detection method for grout fullness of prestressed bridge ducts is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The present invention aims to provide a method and system for analyzing the fullness of grouting in ducts, and to design a method for detecting void defects in grouting in ducts that is different from the existing impact echo method, so as to improve the accuracy of grouting fullness analysis.

[0006] To achieve the above objectives, the first aspect of the present invention provides a method for detecting the fullness of grouting in ducts, applicable to grouting components, the analytical method comprising the following steps: A broadband excitation is applied to the grouting component to induce defect resonance; the resonance signal of the defect resonance is obtained, and then the resonance signal is subjected to Fourier transform to obtain the resonance spectrum; based on the resonance spectrum, the void defects of the grouting component are analyzed to obtain the grouting fullness analysis result.

[0007] The aforementioned method for detecting the fullness of grout filling in ducts applies broadband excitation to the grouting component, ensuring the excitation frequency band covers the natural frequency of the void defects, thereby inducing resonance in the void defects. The fullness of the grout filling is detected by directly detecting the resonance wave signal emitted by the void defects. This method directly uses the void defects as the vibration source, directly detecting the resonance signal excited to the surface of the component. Compared to the traditional impact-echo method, which uses an impact hammer as the vibration source to detect the echo signal reflected back after the shock wave is excited from the component surface and encounters the internal void defects, this method detects the resonance signal through a propagation path that is only half that of the impact echo. The resonance signal attenuation is small, resulting in deeper detection depth, less interference, and higher accuracy of the obtained resonance spectrum, ultimately improving the accuracy of grout fullness analysis.

[0008] Preferably, the step of acquiring the resonance signal of the defect resonance and then performing a Fourier transform on the resonance signal to obtain the resonance spectrum includes: A number of primary detection points are determined on the surface of the grouting component; the primary resonance signal of each primary detection point is acquired; the primary resonance signal of each primary detection point is subjected to Fourier transform to obtain the primary resonance spectrum corresponding to each primary detection point; and all the primary resonance spectra are taken as the resonance spectrum.

[0009] This preferred embodiment employs multiple detection points to collaboratively detect the resonance signal excited to the component surface by void defects. Several of these primary detection points are arranged in an array on the surface of the grouting component. Specifically, the array arrangement includes, but is not limited to: 1) a linear array, with the corrugated pipe inside the grouting component as the center, arranged at equal intervals along a straight line; 2) a grid array, with the corrugated pipe inside the grouting component as the center, arranging a grid-like group of detection points (e.g., a 5×5 array) on the surface of the grouting component, covering a larger detection area; 3) a ring array, with the corrugated pipe inside the grouting component as the center, and a ring-shaped group of detection points arranged around it. Compared to measuring a single resonance spectrum with a single detection point, this embodiment can increase the detection range, covering the propagation range of the spherical wave form of the resonance signal; thus enabling more accurate defect identification and avoiding signal blind spots of a single detection point.

[0010] Preferably, before performing Fourier transform on the resonant first-order signal of each of the first-order detection points to obtain the resonant first-order spectrum corresponding to each of the first-order detection points, the method further includes: Each of the first-order resonant signals is filtered to remove noise from each of the first-order resonant signals.

[0011] In this preferred embodiment, before performing a Fourier transform on the time-domain curve of the first-order resonance signal to convert the time-domain signal into a frequency-domain signal and obtain the resonance spectrum, the first and second resonance signals are first filtered to remove environmental noise such as surface waves of the grouting component, thereby improving the accuracy of subsequent grouting fullness analysis. As an example, in one embodiment, the above filtering method can be Gaussian filtering.

[0012] Preferably, the step of acquiring the resonance signal of the defect resonance and then performing a Fourier transform on the resonance signal to obtain the resonance spectrum includes: A first detection point and a second detection point are determined on the surface of the grouting component; a first resonance signal of the first detection point and a second resonance signal of the second detection point are obtained; Fourier transforms are performed on the first resonance signal and the second resonance signal respectively to obtain a first resonance spectrum and a second resonance spectrum, and the first resonance spectrum and the second resonance spectrum are used as the resonance spectrum.

[0013] This preferred embodiment simultaneously measures the first and second resonance spectra of two detection points. Compared to measuring a single resonance spectrum at a single detection point, this increases the detection range, covering the propagation range of the spherical wave form of the resonance signal. Analyzing the void defects in the grouting component using the first and second resonance spectra measured at the two detection points enables more accurate defect identification and avoids signal blind spots at a single detection point. Furthermore, based on the time difference between the reception of the resonance signals at the two detection points, void defect location can be achieved, providing richer analysis results on the fullness of the grouting in the duct.

[0014] Preferably, the step of analyzing the void defects of the grouting component based on the resonance spectrum to obtain the grouting fullness analysis result includes: Determine the cross-section of the grouting component; Based on the first resonance spectrum and the second resonance spectrum, the resonance frequency amplitude of each block in the cross section of the component is obtained; based on the resonance frequency amplitude of each block, a resonance frequency amplitude cloud map of the grouting component is drawn; based on the resonance frequency amplitude cloud map, the void defect is analyzed to obtain the grouting fullness analysis result.

[0015] This preferred embodiment first determines a cross-section of the grouting component and divides the cross-section into several equal blocks, forming a cross-sectional grid. Each block within the grid is then analyzed individually. Specifically, this preferred embodiment obtains the resonant frequency of each block from the first and second resonant spectra, and then fills the block with a corresponding color based on the resonant frequency amplitude corresponding to the resonant frequency of each block. This results in each block in the grid of the component's cross-section being filled with a color corresponding to its resonant frequency amplitude, forming a resonant frequency amplitude cloud map of the grouting component. This visualizes the changes in the resonant frequency amplitude of each block in the component's cross-section. Analysis based on the resonant frequency amplitude cloud map reveals that the location of high-amplitude peaks indicates the presence of voids or defects. This allows for a direct assessment of the grouting fullness within the component, enabling the location of voids and defects and improving the accuracy of grouting fullness analysis.

[0016] Preferably, obtaining the resonant frequency amplitude of each block within the cross-section of the component based on the first resonant spectrum and the second resonant spectrum includes: For any of the blocks: Obtain a first distance between the block and the first detection point, and obtain a second distance between the block and the second detection point; obtain a first resonant frequency based on the first distance and a preset component wave velocity, and obtain a second resonant frequency based on the second distance and the component wave velocity; obtain a first frequency amplitude based on the first resonant frequency and the first resonant spectrum, and obtain a second frequency amplitude based on the second resonant frequency and the second resonant spectrum; obtain the resonant frequency amplitude of the block based on the first frequency amplitude and the second frequency amplitude.

[0017] It should be noted that if the first distance is L1, the second distance is L2, and the wave velocity of the grouting component is C, then the first frequency F1 of the block is C / L1, and the second frequency F2 is C / L2. After obtaining the first and second frequencies of the block, the first frequency amplitude A1 corresponding to the first frequency and the second frequency amplitude A2 corresponding to the second frequency can be obtained from the known first and second spectra. The frequency amplitudes of the block are then superimposed to obtain the resonant frequency amplitude A of the block, as shown in the following formula: A = (A1 + A2) / 2; Preferably, applying broadband excitation to the grouting member to induce defect resonance in the grouting member includes: A vibration bullet is ejected onto the surface of the grouting member to generate a broadband vibration wave on the surface of the grouting member, thereby applying broadband vibration to the grouting member.

[0018] This preferred embodiment employs a catapult-launched excitation projectile to apply broadband excitation. The excitation wave generated by the projectile on the surface of the grouting component contains a wide frequency range, which can cover the natural frequency of the void defect. Therefore, when the excitation projectile is launched onto the surface of the grouting component, this broadband excitation can induce resonance in the void defect inside the grouting component. When the resonance wave generated by the void defect resonance is transmitted to the surface of the component, its amplitude will be much larger than the echo of the incident excitation wave, thus enabling the detector to distinguish between the incident wave echo and the defect resonance wave.

[0019] Based on the above principle, the propagation path of the resonance signal detected by this method is only half that of the impulse echo, and the frequency calculation formula is significantly different from that of the traditional impulse echo method. The frequency calculation formula of this invention is shown below: f1=C p / d; Where f1 is the resonant signal frequency; C p d represents the wave velocity of the component; d represents the depth of the void defect, i.e., the distance from the void defect to the detection point.

[0020] The formula for calculating the frequency using the traditional impulse echo method is shown below: f2=C p / 2d; Where f1 is the echo signal frequency; C p d represents the wave velocity of the component; d represents the depth of the void defect, i.e., the distance from the void defect to the detection point.

[0021] Therefore, the resonance signal attenuation of the present invention is small, resulting in a deeper detection depth, less interference, and higher accuracy of the obtained resonance spectrum, ultimately improving the accuracy of grout fullness analysis.

[0022] A second aspect of the present invention provides a grouting fullness analysis system for duct grouting components. The system includes a catapult, a first accelerometer, a digital-to-analog converter module, and a host computer, wherein: The ejector gun is disposed on the surface of the grouting component and is used to apply broadband excitation to the grouting component to induce defect resonance in the grouting component. The first acceleration sensor is set at the first detection point of the grouting component and is used to acquire the resonance signal of the defect resonance; The digital-to-analog conversion module is used to perform Fourier transform on the resonance signal to obtain the resonance spectrum; The host computer is used to analyze the void defects of the grouting component based on the resonance spectrum, and obtain the grouting fullness analysis results.

[0023] The aforementioned grouting fullness analysis system applies broadband excitation to the grouting component, covering the natural frequency of the void defect, thereby inducing resonance in the void defect. Grouting fullness is determined by directly detecting the resonance wave signal emitted by the void defect. This method directly uses the void defect as the vibration source, directly detecting the resonance signal excited to the component surface. Compared to the traditional impact echo method, which uses an impact hammer as the vibration source to detect the echo signal reflected back after the shock wave is excited from the component surface and encounters the internal void defect, this method detects the resonance signal through a propagation path that is only half that of the impact echo. The resonance signal attenuation is small, resulting in deeper detection depth, less interference, and higher accuracy of the obtained resonance spectrum, ultimately improving the accuracy of grouting fullness analysis.

[0024] Preferably, the grouting fullness analysis system further includes a second acceleration sensor, wherein: The first accelerometer is used to acquire the first resonance signal of the defect resonance; The second acceleration sensor is disposed at the second detection point of the grouting component and is used to acquire the second resonance signal of the defect resonance; The digital-to-analog conversion module is used to perform Fourier transforms on the first resonance signal and the second resonance signal respectively to obtain the first resonance spectrum and the second resonance spectrum, and to use the first resonance spectrum and the second resonance spectrum as the resonance spectrum.

[0025] This preferred embodiment simultaneously measures the first and second resonance spectra of two detection points. Compared to measuring a single resonance spectrum at a single detection point, this increases the detection range, covering the propagation range of the spherical wave form of the resonance signal. Analyzing the void defects in the grouting component using the first and second resonance spectra measured at the two detection points enables more accurate defect identification and avoids signal blind spots at a single detection point. Furthermore, based on the time difference between the reception of the resonance signals at the two detection points, void defect location can be achieved, providing richer analysis results on the fullness of the grouting in the duct.

[0026] Preferably, in the host computer, the step of analyzing the void defects of the grouting component based on the resonance spectrum to obtain the grouting fullness analysis result includes: Determine the cross-section of the grouting component; Based on the first resonance spectrum and the second resonance spectrum, the resonance frequency amplitude of each block in the cross section of the component is obtained; based on the resonance frequency amplitude of each block, a resonance frequency amplitude cloud map of the grouting component is drawn; based on the resonance frequency amplitude cloud map, the void defect is analyzed to obtain the grouting fullness analysis result.

[0027] This preferred embodiment first determines a cross-section of the grouting component and divides the cross-section into several equal blocks, forming a cross-sectional grid. Each block within the grid is then analyzed individually. Specifically, this preferred embodiment obtains the resonant frequency of each block from the first and second resonant spectra, and then fills the block with a corresponding color based on the resonant frequency amplitude corresponding to the resonant frequency of each block. This results in each block in the grid of the component's cross-section being filled with a color corresponding to its resonant frequency amplitude, forming a resonant frequency amplitude cloud map of the grouting component. This visualizes the changes in the resonant frequency amplitude of each block in the component's cross-section. Analysis based on the resonant frequency amplitude cloud map reveals that the location of high-amplitude peaks indicates the presence of voids or defects. This allows for a direct assessment of the grouting fullness within the component, enabling the location of voids and defects and improving the accuracy of grouting fullness analysis.

[0028] Preferably, in the host computer, obtaining the resonant frequency amplitude of each block within the cross-section of the component based on the first resonant spectrum and the second resonant spectrum includes: For any block: Obtain a first distance between the block and the first detection point, and obtain a second distance between the block and the second detection point; obtain a first resonant frequency based on the first distance and a preset component wave velocity, and obtain a second resonant frequency based on the second distance and the component wave velocity; obtain a first frequency amplitude based on the first resonant frequency and the first resonant spectrum, and obtain a second frequency amplitude based on the second resonant frequency and the second resonant spectrum; obtain the resonant frequency amplitude of the block based on the first frequency amplitude and the second frequency amplitude.

[0029] It should be noted that if the first distance is L1, the second distance is L2, and the wave velocity of the grouting component is C, then the first frequency F1 of the block is C / L1, and the second frequency F2 is C / L2. After obtaining the first and second frequencies of the block, the first frequency amplitude A1 corresponding to the first frequency and the second frequency amplitude A2 corresponding to the second frequency can be obtained from the known first and second spectra. The frequency amplitudes of the block are then superimposed to obtain the resonant frequency amplitude A of the block, as shown in the following formula: A = (A1 + A2) / 2; Preferably, the ejection gun includes a barrel, a barrel section, a support portion, and a limiting portion; the support portion is connected to the barrel to stably press against the surface of the grouting component; the barrel is connected to the barrel section; the limiting portion confines the excitation projectile inside the barrel section; wherein: When the ejector gun releases the limiting part from restricting the excitation bullet, the excitation bullet leaves the gun barrel and is ejected along the gun barrel to the surface of the grouting component, so as to generate a broadband excitation wave on the surface of the grouting component, thereby applying broadband excitation to the grouting component.

[0030] This preferred embodiment employs a catapult-launched excitation projectile to apply broadband excitation. The excitation wave generated by the projectile on the surface of the grouting component contains a wide frequency range, which can cover the natural frequency of the void defect. Therefore, when the excitation projectile is launched onto the surface of the grouting component, this broadband excitation can induce resonance in the void defect inside the grouting component. When the resonance wave generated by the void defect resonance is transmitted to the surface of the component, its amplitude will be much larger than the echo of the incident excitation wave, thus enabling the detector to distinguish between the incident wave echo and the defect resonance wave.

[0031] Preferably, the excitation bullet includes a conical projectile, the projectile has a cone angle of a preset taper, the projectile length of a preset length, and the conical projectile is made of a material with a predetermined elastic modulus.

[0032] In this embodiment, by changing the taper angle and length of the projectile, the frequency range of the broadband excitation wave generated by the excitation projectile on the surface of the grouting component can be altered. Furthermore, by using materials with different elastic moduli to manufacture the conical projectile, the stress-strain condition when the conical projectile is ejected onto the surface of the grouting component can be changed, thereby altering the frequency range of the broadband excitation wave generated by the excitation projectile on the surface of the grouting component.

[0033] In one possible embodiment, the material includes, but is not limited to, at least one of titanium alloy, aluminum alloy, or engineering plastic. Attached Figure Description

[0034] Figure 1 This is a schematic flowchart of a method for analyzing the fullness of grouting in a duct, provided in an embodiment of the present invention. Figure 2 This is a schematic diagram illustrating the principle of a grouting fullness analysis method for ducts provided in an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the principle of a traditional impact echo method provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the detection point setting for a grouting fullness analysis method for ducts provided in an embodiment of the present invention; Figure 5 This is a schematic diagram illustrating the principle of a grouting fullness analysis method for ducts provided in an embodiment of the present invention; Figure 6 This is a spectrum diagram of a grouting fullness analysis method provided in an embodiment of the present invention; Figure 7 This is a resonance frequency amplitude cloud map of a grouting fullness analysis method provided in an embodiment of the present invention; Figure 8 This is a resonance frequency amplitude cloud map of another method for analyzing the fullness of grouting in ducts provided in this embodiment of the invention; Figure 9 This is a schematic diagram of the structure of a grouting fullness analysis system provided in an embodiment of the present invention; Figure 10 This is a three-dimensional structural diagram of a catapult gun provided in an embodiment of the present invention; Figure 11 This is a side sectional view of a catapult gun provided in an embodiment of the present invention; Figure 12 This is a top sectional view of a catapult gun provided in an embodiment of the present invention; Figure 13 a is a side view of a second gun barrel provided in an embodiment of the present invention; Figure 13 b is a front view of a second gun barrel provided in an embodiment of the present invention; Figure 14 a is a bottom view of a gun pin provided in an embodiment of the present invention; Figure 14 b is a side view of a gun pin provided in an embodiment of the present invention; The components include: 1. Ejector gun; 11. Vibration bullet; 12. First barrel; 121. Ball bushing; 122. Sliding component; 123. First spring; 13. Second barrel; 131. Ejector pin; 132. Transition component; 133. Gun pin; 134. Second spring; 135. First nut; 136. Pin; 137. Hand operating component; 138. Guide pin; 14. Barrel; 141. Support plate; 142. Support screw; 143. Second nut; 15. Cylinder cover; 21. First accelerometer; 22. Second accelerometer; 23. Impact hammer; 24. Impact echo sensor; 3. Analog-to-digital converter module; 4. Host computer; 5. Grouting component; 51. Cavity defect; 52. Corrugated pipe. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following detailed descriptions are exemplary and intended to provide further detailed explanation of the invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings, are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings are used to distinguish different objects, not to describe a particular order.

[0036] It should be understood that although the steps in the flowcharts of the accompanying figures are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the accompanying figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0037] During the manufacturing process of bridge ducts, insufficient grouting fullness can easily lead to voids within the duct components. Therefore, detecting the grouting fullness of prestressed bridge ducts is a key technical challenge in the field of bridge engineering material testing and analysis. Although various testing methods have been developed in the industry, their practical applications are significantly limited due to the inherent characteristics of their different technical principles. For example, the impact-echo method has some detection capability for internal defects in large-sized metal corrugated pipes, but it is prone to missed or false detections in areas with dense reinforcement, and its accuracy decreases with the depth of the defect.

[0038] Reference Figure 2The existing impact-echo method is an echo-based detection technique. This method involves manually striking the surface of a component with an impact hammer 23 to generate longitudinal waves. An impact-echo sensor 24 detects the echo characteristics of the mechanical longitudinal waves reflected inside the component to identify internal void defects 51. This method has a certain detection capability for larger voids or segregation defects in metal bellows 52, but its resolution and sensitivity are limited by the diameter of the impact hammer 23: ordinary impact hammers 23 can only generate longitudinal waves of a single frequency, and different hammer diameters produce longitudinal waves with different wavelengths. There is a lack of methods for selecting a suitable impact hammer 23 size when the size and depth of the defect are unknown. Furthermore, in areas with dense reinforcement, the longitudinal waves incident from the component surface encounter internal defects and are reflected, resulting in a propagation path length twice the depth of the defect. This leads to significant wave signal attenuation and increased susceptibility to interference, such as wavefront distortion caused by the difference in wave velocity between the reinforcement and concrete, scattering effects caused by dense reinforcement mesh, and coupled vibration interference from the metal bellows 52, making it prone to missed or false detections.

[0039] In addition, other existing measurement methods all have limitations in application scenarios to varying degrees. For example, ultrasonic testing is easily affected by factors such as reinforcing bars, has limited accuracy in detecting small defects, and fails in prestressed bridges with dense reinforcing bars. X-ray testing is harmful to the human body, and the equipment is expensive, the testing cost is high, and the testing speed is slow, making it unsuitable for large-scale on-site testing. Ground penetrating radar has limited detection depth, is not effective in detecting deep defects, and is easily affected by surrounding metal objects and environmental factors.

[0040] Therefore, how to optimize the detection method for grout fullness of prestressed bridge ducts is a technical problem that urgently needs to be solved in this field.

[0041] To solve the above technical problems, refer to Figure 1 This invention provides a method for detecting the fullness of grouting in ducts, applicable to grouting components 5. The analysis method includes the following steps: S10. Apply broadband excitation to the grouting component 5 to induce defect resonance in the grouting component 5. S20. Obtain the resonance signal of the defect resonance, and then perform Fourier transform on the resonance signal to obtain the resonance spectrum; S30. Based on the resonance spectrum analysis, the void defect 51 of the grouting component 5 is analyzed to obtain the grouting fullness analysis result.

[0042] The above-mentioned method for detecting the fullness of grouting in ducts applies broadband excitation to the grouting component 5, so that the excitation frequency band covers the natural frequency of the void defect 51 in the grouting component 5, thereby inducing resonance of the void defect 51. The fullness of grouting in ducts is determined by directly detecting the resonance wave signal emitted by the void defect 51.

[0043] Preferably, the step of acquiring the resonance signal of the defect resonance and then performing a Fourier transform on the resonance signal to obtain the resonance spectrum includes: Several primary detection points are determined on the surface of the grouting component 5; the resonance primary signal of each primary detection point is acquired; Fourier transform is performed on the resonance primary signal of each primary detection point to obtain the resonance primary spectrum corresponding to each primary detection point; and all the resonance primary spectra are taken as the resonance spectrum.

[0044] This preferred embodiment employs multiple detection points to collaboratively detect the resonance signal excited to the surface of the component by void defects. Several of these primary detection points are arranged in an array on the surface of the grouting component 5. Specifically, the array arrangement includes, but is not limited to: 1) a linear array, with the corrugated pipe 52 within the grouting component 5 as the center, arranged at equal intervals along a straight line; 2) a grid array, with a grid-like group of detection points (e.g., a 5×5 array) arranged on the surface of the grouting component 5, centered on the corrugated pipe 52, covering a larger detection area; and 3) a ring array, with a group of detection points arranged in a ring around the corrugated pipe 52 within the grouting component 5. Compared to measuring a single resonance spectrum with a single detection point, this embodiment increases the detection range, covering the propagation range of the spherical wave form of the resonance signal; thus enabling more accurate defect identification and avoiding signal blind spots from a single detection point.

[0045] Preferably, before performing Fourier transform on the resonant first-order signal of each of the first-order detection points to obtain the resonant first-order spectrum corresponding to each of the first-order detection points, the method further includes: Each of the first-order resonant signals is filtered to remove noise from each of the first-order resonant signals.

[0046] In this preferred embodiment, before performing a Fourier transform on the time-domain curve of the first-order resonance signal to convert the time-domain signal into a frequency-domain signal and obtain the resonance spectrum, the first and second resonance signals are first filtered to remove environmental noise such as surface waves of the grouting component, thereby improving the accuracy of subsequent grouting fullness analysis. As an example, in one embodiment, the above filtering method can be Gaussian filtering.

[0047] Reference Figure 2 Preferably, applying broadband excitation to the grouting member 5 to induce defect resonance in the grouting member 5 includes: S11. Ejecting a vibration bullet 11 onto the surface of the grouting member 5 to generate a broadband vibration wave on the surface of the grouting member 5, thereby applying broadband vibration to the grouting member 5.

[0048] In this preferred embodiment, a broadband excitation is applied by launching an excitation bullet 11 from a catapult 1. The excitation wave generated by the excitation bullet 11 on the surface of the grouting component 5 contains a wide frequency range, which can cover the natural frequency of the void defect 51. Therefore, when the excitation bullet 11 is launched onto the surface of the grouting component 5, the broadband excitation can induce resonance in the void defect 51 inside the grouting component 5. When the resonance wave generated by the void defect 51 is transmitted to the surface of the component, its amplitude will be much larger than the echo of the incident excitation wave, thereby enabling the detector to distinguish between the incident wave echo and the defect resonance wave.

[0049] Please refer to Figure 2 and Figure 3 , Figure 2 This is a schematic diagram illustrating the principle of the above-mentioned method for analyzing the fullness of grouting in the ducts; Figure 3 This is a schematic diagram illustrating the principle of a conventional impact echo method provided in an embodiment of the present invention. In this embodiment, the void defect 51 is directly used as the vibration source to directly detect the resonance signal excited by the void defect 51 to the surface of the component. The farthest distance the resonance signal propagates is the defect depth d. The conventional impact echo method uses an impact hammer 23 as the vibration source and utilizes an impact echo sensor 24 to detect the echo signal reflected back after the shock wave is excited from the surface of the component and encounters the internal void defect 51. The farthest distance the shock wave propagates is twice the defect depth 2d.

[0050] Based on the above principle, the propagation path of the resonance signal detected by this method is only half that of the impulse echo, and the frequency calculation formula is significantly different from that of the traditional impulse echo method. The frequency calculation formula of this invention is shown below: f1=C p / d; Where f1 is the resonant signal frequency; C p d represents the wave velocity of the component; d represents the depth of the void defect 51, i.e., the distance from the void defect 51 to the detection point.

[0051] The formula for calculating the frequency using the traditional impulse echo method is shown below: f2=C p / 2d; Where f1 is the echo signal frequency; C p d represents the wave velocity of the component; d represents the depth of the void defect 51, i.e., the distance from the void defect 51 to the detection point.

[0052] Therefore, compared with the traditional impact echo method, the propagation path of the resonance signal detected by this method is only half that of the impact echo method. The resonance signal attenuation is small, so the detection depth is deeper, less interference is encountered, and the accuracy of the obtained resonance spectrum is higher, ultimately improving the accuracy of the grout fullness analysis.

[0053] Reference Figure 2 Preferably, the step of obtaining the resonance signal of the defect resonance and then performing a Fourier transform on the resonance signal to obtain the resonance spectrum includes: S21. Determine the first and second detection points on the surface of the grouting component 5. S22. Obtain the first resonance signal of the first detection point through the first acceleration sensor 21; and obtain the second resonance signal of the second detection point through the second acceleration sensor 22; specifically, the first resonance signal and the second resonance signal are time-domain signals collected by the acceleration sensor.

[0054] S23. Perform Fourier transform on the first resonance signal and the second resonance signal respectively to obtain the first resonance spectrum and the second resonance spectrum, and use the first resonance spectrum and the second resonance spectrum as the resonance spectrum.

[0055] This preferred embodiment simultaneously measures the first and second resonance spectra of two detection points. Compared to measuring a single resonance spectrum at a single detection point, this increases the detection range, covering the propagation range of the spherical wave form of the resonance signal. Analyzing the void defect 51 of the grouting component 5 using the first and second resonance spectra measured at the two detection points enables more accurate defect identification and avoids signal blind spots at a single detection point. Furthermore, based on the time difference between the reception of the resonance signals at the two detection points, the void defect 51 can be located, providing richer analysis results on the grouting fullness of the duct.

[0056] Reference Figure 4 Furthermore, for the grouting component 5, the void defect 51 is usually located near the internal bellows 52. Therefore, in order to enable the detection range of the first acceleration sensor 21 and the second acceleration sensor 22 to cover the entire cross-section of the bellows 52 and to achieve blind-angle detection of the possible void defect 51, this embodiment arranges the first acceleration sensor 21 and the second acceleration sensor 22 symmetrically on both sides of the bellows 52 perpendicular to the axis of the bellows 52; the impact point of the excitation bullet 11 ejected into the grouting component 5 is located in the middle of the line connecting the two acceleration sensors, directly opposite the axis of the bellows 52.

[0057] Reference Figure 5 Preferably, the step of analyzing the void defects 51 of the grouting component 5 based on the resonance spectrum to obtain the grouting fullness analysis result includes: S31. Based on the first resonance spectrum and the second resonance spectrum, obtain the resonance frequency amplitude of each block p in the grouting component 5; S32. Based on the resonance frequency amplitude of each block, draw a resonance frequency amplitude cloud map of the grouting component 5. S33. Based on the resonance frequency amplitude cloud map, analyze the void defect 51 to obtain the grouting fullness analysis result of the duct.

[0058] This preferred embodiment first determines a cross-section of the grouting component 5 and divides the cross-section into several blocks p, forming a cross-sectional grid. Each block p in the grid is then analyzed individually. Specifically, this preferred embodiment obtains the resonance frequency of each block p from the first resonance spectrum and the second resonance spectrum. Based on the resonance frequency amplitude corresponding to the resonance frequency of each block p, a corresponding color is filled into the block p. Ultimately, each block p in the grid of the component's cross-section is filled with a color corresponding to its resonance frequency amplitude, forming a resonance frequency amplitude cloud map of the grouting component 5. This visualizes the changes in the resonance frequency amplitude of each block p in the component's cross-section. Analysis based on the resonance frequency amplitude cloud map reveals that the location of high-amplitude peaks indicates the presence of void defects 51. This allows for a direct assessment of the grouting fullness within the component, enabling the location of void defects 51 and improving the accuracy of grouting fullness analysis.

[0059] Furthermore, referring to Figure 4 and Figure 5 In a preferred embodiment, the first accelerometer 21 and the second accelerometer 22 are symmetrically arranged on both sides of the bellows 52, perpendicular to the axis of the bellows 52. The distance D1 between the first accelerometer 21 and the axis of the bellows 52, and the distance D2 between the second accelerometer 22 and the axis of the bellows 52, are both 50 mm. The impact point of the excitation bullet 11 ejected into the grouting member 5 is located in the middle of the line connecting the two accelerometers, with a distance D1 from the first accelerometer 21 and a distance D2 from the second accelerometer 22 both 50 mm, directly facing the axis of the bellows 52. In this embodiment, setting D1=D2=50 mm allows for accurate determination of the spatial coordinates of each block p within the grouting member 5, facilitating subsequent defect detection and location. In another possible embodiment, D1≠D2 is set for filtering and complex detection.

[0060] Reference Figure 5 and Figure 6 Preferably, obtaining the resonant frequency amplitude of each block within the grouting component 5 based on the first resonant spectrum and the second resonant spectrum includes: For any of the blocks p: S311. Obtain the first distance between the block p and the first detection point, and obtain the second distance between the block p and the second detection point; S312. Obtain the first resonant frequency based on the first distance and the preset component wave velocity, and obtain the second resonant frequency based on the second distance and the component wave velocity; S313. Obtain a first frequency amplitude based on the first resonant frequency and the first resonant spectrum, and obtain a second frequency amplitude based on the second resonant frequency and the second resonant spectrum; S314. Obtain the resonant frequency amplitude of block p based on the first frequency amplitude and the second frequency amplitude.

[0061] It should be noted that if the first distance is L1, the second distance is L2, and the wave velocity of the grouting component 5 is C, then the first resonant frequency F1 of this block is C / L1, and the second resonant frequency F2 is C / L2. After obtaining the first resonant frequency F1 and the second resonant frequency F2 of this block, the first frequency amplitude A1 corresponding to the first resonant frequency F1 and the second frequency amplitude A2 corresponding to the second resonant frequency F2 can be obtained from the known first and second resonant spectra. The frequency amplitudes of this block are then superimposed to obtain the resonant frequency amplitude A of this block p, as shown in the following formula: A = (A1 + A2) / 2; Reference Figure 7 and Figure 8 , Figure 7 and Figure 8 This is a schematic diagram of the resonance frequency amplitude cloud map provided in an embodiment of the present invention. After obtaining the resonance frequency amplitude of each block p, the resonance frequency amplitude corresponding to each block p in the cross-sectional grid of the component is displayed in color on the cross-sectional grid of the component. The color mapping adopts a thermodynamic color map, using warm and cool colors to represent the magnitude of the frequency amplitude, where warm colors correspond to high frequency amplitude and cool colors correspond to low frequency amplitude.

[0062] like Figure 7 The image shows the resonance frequency amplitude cloud map of the grouting component 5 with void defects 51, where the cross-section of the corrugated pipe 52 is represented by a red circle. Observation and analysis reveal that this resonance frequency amplitude cloud map is a grid of the component's cross-section, where each grid block p is color-coded to display its corresponding resonance frequency amplitude. Figure 7 The warm-colored arc-shaped distribution on the front end of the wall of the corrugated pipe 52 indicates that a high-amplitude signal frequency has appeared at the front end of the wall of the corrugated pipe 52. It is determined that a resonant frequency has been generated here, indicating that there is a void defect 51 here.

[0063] like Figure 8The image shows the resonance frequency amplitude cloud map of the grouting component 5 without voids or defects 51, where the cross-section of the corrugated pipe 52 is represented by a red circle. Observation and analysis reveal that this resonance frequency amplitude cloud map is a grid of the component's cross-section, where each grid block p displays its corresponding resonance frequency amplitude in color. Figure 8 The area around the corrugated pipe 52 is all cool-colored, indicating that the area around the corrugated pipe 52 is all low-amplitude signal frequencies. Therefore, it can be determined that no resonant frequency is generated here, indicating that there is no void defect 51 here.

[0064] Reference Figures 9-11 This invention also provides a grouting fullness analysis system for ducts, applicable to grouting components 5. The analysis system includes a catapult 1, a first accelerometer 21, a second accelerometer 22, a digital-to-analog converter 3, and a host computer 4, wherein: The ejector gun 1 is disposed on the surface of the grouting component 5 and is used to apply broadband excitation to the grouting component 5 so as to induce defect resonance in the grouting component 5. The first acceleration sensor 21 is disposed at the first detection point of the grouting component 5 and is used to acquire the first resonance signal of the defect resonance; The second acceleration sensor 22 is disposed at the second detection point of the grouting component 5 and is used to acquire the second resonance signal of the defect resonance; The digital-to-analog conversion module 3 is used to perform Fourier transform on the first resonance signal and the second resonance signal respectively to obtain the first resonance spectrum and the second resonance spectrum, and to use the first resonance spectrum and the second resonance spectrum as the resonance spectrum; The host computer 4 is used to analyze the void defects 51 of the grouting component 5 based on the resonance spectrum, and obtain the grouting fullness analysis results.

[0065] Reference Figures 10-12 , Figure 13 a, Figure 13 b、 Figure 14 a and Figure 14 b. Preferably, the ejection gun 1 includes a barrel 14, a barrel, a support portion, and a limiting portion; the support portion is connected to the barrel 14 so that the barrel 14 stably presses against the surface of the grouting member 5; the barrel 14 is connected to the barrel; the limiting portion confines the excitation bullet 11 inside the barrel; wherein: When the ejector gun 1 releases the limiting part from restricting the excitation bullet 11, the excitation bullet 11 leaves the gun barrel and is ejected along the gun barrel 14 to the surface of the grouting member 5, so as to generate a broadband excitation wave on the surface of the grouting member 5, thereby applying broadband excitation to the grouting member 5.

[0066] Furthermore, the barrel includes a first barrel 12 and a second barrel 13. The rear end of the first barrel 12 is connected to a barrel cap 15, the front end of the first barrel 12 is connected to the rear end of the second barrel 13, and the front end of the second barrel 13 is connected to a barrel 14 via a transition piece 132. The first gun barrel 12 is provided with a ball bushing 121, a slider 122 and a first spring 123 inside; the ball bushing 121 is used to provide a smooth surface for the slider 122 and reduce the friction of the slider 122. The second barrel 13 is provided with a ejector pin 131 inside, and the sliding member 122 and the ejector pin 131 are threadedly connected; The second barrel 13 also has a movable gun pin 133 inside, the second spring 134, the barrel cover 15, the first nut 135 are connected to the gun pin 133, and the hand operating part 137 is rotatably connected to the gun pin 133 through the pin 136. The second barrel 13 is also provided with a guide pin 138, which presses against the gun pin 133 to lock it in place; The outer wall of the barrel 14 is connected to a support part, which includes a support plate 141, a support screw 142, and a second nut 143. The support plate 141 is connected to the outer wall of the gun barrel 14, and the support screw 142 is threadedly connected to the support plate 141 through the second nut 143.

[0067] The principle by which the ejector gun 1 ejects the vibrating bullet 11 is as follows: Opening the barrel cover 15 allows the excitation bullet 11 to be inserted into the first barrel 12 from the rear end, so that the excitation bullet 11 is pressed by the first spring 123. At this time, the guide pin 138 is pulled from the second barrel 13 toward the first barrel 12, so that the guide pin 138 presses against the gun pin 133, thereby pushing the gun pin 133 into the inner wall of the second barrel 13 under the elastic force of the second spring 134, so that the gun pin 133 locks the sliding member 122 and the ejector pin 131 connected to the sliding member 122, thereby confining the excitation bullet 11 inside the first barrel 12. When it is necessary to eject the excitation bullet 11, pressure is applied to the hand operating member 137 to make it rotate, so that the hand operating member 137 pulls the gun pin 133 through the pin 136, so that the gun pin 133 exits the inner wall of the second gun barrel 13; at this time, the first spring 123 and the sliding member 122 are no longer restricted; the first spring 123 releases the compression force to make the sliding member 122 and the ejector pin 131 pop out, thereby causing the excitation bullet 11 to be ejected along the barrel 14.

[0068] In this preferred embodiment, a broadband excitation is applied by launching an excitation bullet 11 from a catapult 1. The excitation wave generated by the excitation bullet 11 on the surface of the grouting component 5 contains a wide frequency range, which can cover the natural frequency of the void defect 51. Therefore, when the excitation bullet 11 is launched onto the surface of the grouting component 5, the broadband excitation can induce resonance in the void defect 51 inside the grouting component 5. When the resonance wave generated by the void defect 51 is transmitted to the surface of the component, its amplitude will be much larger than the echo of the incident excitation wave, thereby enabling the detector to distinguish between the incident wave echo and the defect resonance wave.

[0069] Preferably, the excitation bullet 11 includes a conical projectile, which has a certain projectile cone angle and projectile length, and is made of a material with a predetermined elastic modulus.

[0070] In this embodiment, by changing the taper angle of the projectile and the length of the projectile, the frequency range of the broadband excitation wave generated by the excitation projectile 11 on the surface of the grouting component can be altered. Furthermore, by using materials with different elastic moduli to manufacture the conical projectile, the stress-strain condition when the conical projectile is ejected onto the surface of the grouting component can be changed, thereby altering the frequency range of the broadband excitation wave generated by the excitation projectile 11 on the surface of the grouting component.

[0071] In one possible embodiment, the material includes, but is not limited to, at least one of titanium alloy, aluminum alloy, or engineering plastic.

[0072] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0073] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; however, any combination of these technical features that does not contradict each other should be considered within the scope of this specification.

[0074] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the concept of this application, and these improvements and substitutions should also be considered within the scope of protection of this invention. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A method for analyzing the fullness of grout filling in ducts, characterized in that, This analytical method is applicable to grouting components and includes the following steps: A broadband excitation is applied to the grouting member to induce defect resonance in the grouting member. The resonance signal of the defect resonance is obtained, and then a Fourier transform is performed on the resonance signal to obtain the resonance spectrum, specifically: Determine the first and second detection points on the surface of the grouting component; Acquire the first resonance signal of the first detection point and the second resonance signal of the second detection point; Fourier transforms are performed on the first resonance signal and the second resonance signal respectively to obtain the first resonance spectrum and the second resonance spectrum, and the first resonance spectrum and the second resonance spectrum are used as the resonance spectrum; Based on the resonance spectrum analysis of the void defects in the grouting component, the grouting fullness analysis results are obtained, specifically: Determine the cross-section of the grouting component; Based on the first resonance spectrum and the second resonance spectrum, the resonance frequency amplitude of each block within the cross-section of the component is obtained; wherein, for any block: Obtain the first distance between the block and the first detection point, and obtain the second distance between the block and the second detection point; The first resonant frequency is obtained based on the first distance and the preset component wave velocity, and the second resonant frequency is obtained based on the second distance and the component wave velocity. A first frequency amplitude is obtained based on the first resonant frequency and the first resonant spectrum, and a second frequency amplitude is obtained based on the second resonant frequency and the second resonant spectrum; The resonant frequency amplitude of the block is obtained based on the first frequency amplitude and the second frequency amplitude; Based on the resonant frequency amplitude of each block, a resonant frequency amplitude cloud map of the grouting component is drawn. Based on the analysis of the resonance frequency amplitude cloud map, the void defect is obtained, and the grouting fullness analysis result of the duct is obtained.

2. The method for analyzing the fullness of grouting in a duct according to claim 1, characterized in that, The step of acquiring the resonance signal of the defect resonance, and then performing a Fourier transform on the resonance signal to obtain the resonance spectrum, includes: Determine several primary detection points on the surface of the grouting component; The resonant first-order signal of each of the first-order detection points is acquired respectively; Perform Fourier transform on the resonant first-order signal of each of the first-order detection points to obtain the resonant first-order spectrum corresponding to each of the first-order detection points; All of the first-order resonance spectra are taken as the resonance spectrum.

3. The method for analyzing the fullness of grouting in a duct according to claim 2, characterized in that, Before performing Fourier transform on the resonant first-order signal of each of the first-order detection points to obtain the resonant first-order spectrum corresponding to each of the first-order detection points, the method further includes: Each of the first-order resonant signals is filtered to remove noise from each of the first-order resonant signals.

4. The method for analyzing the fullness of grouting in a duct according to claim 1, characterized in that, The step of applying broadband excitation to the grouting member to induce defect resonance in the grouting member includes: A vibration bullet is ejected onto the surface of the grouting member to generate a broadband vibration wave on the surface of the grouting member, thereby applying broadband vibration to the grouting member.

5. A grouting fullness analysis system for ducts, characterized in that, Applicable to grouting components, this analysis system includes a catapult, a first accelerometer, a second accelerometer, a digital-to-analog converter module, and a host computer, wherein: The ejector gun is disposed on the surface of the grouting component and is used to apply broadband excitation to the grouting component to induce defect resonance in the grouting component. The first acceleration sensor is disposed at the first detection point of the grouting component and is used to acquire the first resonance signal of the defect resonance; The second acceleration sensor is disposed at the second detection point of the grouting component and is used to acquire the second resonance signal of the defect resonance; The digital-to-analog conversion module is used to perform Fourier transform on the first resonance signal and the second resonance signal respectively to obtain the first resonance spectrum and the second resonance spectrum, and to use the first resonance spectrum and the second resonance spectrum as the resonance spectrum; The host computer is used to analyze the void defects of the grouting component based on the resonance spectrum, and obtain the grouting fullness analysis results, specifically: Determine the cross-section of the grouting component; Based on the first resonance spectrum and the second resonance spectrum, the resonance frequency amplitude of each block within the cross-section of the component is obtained; wherein, for any block: Obtain the first distance between the block and the first detection point, and obtain the second distance between the block and the second detection point; The first resonant frequency is obtained based on the first distance and the preset component wave velocity, and the second resonant frequency is obtained based on the second distance and the component wave velocity. A first frequency amplitude is obtained based on the first resonant frequency and the first resonant spectrum, and a second frequency amplitude is obtained based on the second resonant frequency and the second resonant spectrum; The resonant frequency amplitude of the block is obtained based on the first frequency amplitude and the second frequency amplitude; Based on the resonant frequency amplitude of each block, a resonant frequency amplitude cloud map of the grouting component is drawn. Based on the analysis of the resonance frequency amplitude cloud map, the void defect is obtained, and the grouting fullness analysis result of the duct is obtained.

6. The grouting fullness analysis system according to claim 5, characterized in that, The ejection gun includes a barrel, a barrel section, a support portion, and a limiting portion; the support portion is connected to the barrel to stably press the barrel against the surface of the grouting component; the barrel is connected to the barrel section; the limiting portion confines the excitation projectile inside the barrel section; wherein: When the ejector gun releases the limiting part from restricting the excitation bullet, the excitation bullet leaves the gun barrel and is ejected along the gun barrel to the surface of the grouting component, so as to generate a broadband excitation wave on the surface of the grouting component, thereby applying broadband excitation to the grouting component.

7. The grouting fullness analysis system according to claim 6, characterized in that, The excitation bullet includes a conical projectile, the cone angle of which is a preset cone angle, the length of which is a preset length, and the conical projectile is made of a material with a predetermined elastic modulus.

Images