Nondestructive testing device for checking sleeve filling degree and nondestructive testing method using same

Abstract

One embodiment of the present invention provides a technology for analyzing the filling degree of a sleeve used in a precast concrete (PC) method by a nondestructive testing method, deriving analysis data therefor, and determining a filling rate using the analysis data. The nondestructive testing device for checking a sleeve filling degree according to an embodiment of the present invention comprises: a transducer connected to one of an inlet and an outlet formed in a sleeve for a PC method to emit ultrasonic waves into the sleeve; a receiver connected to the other of the inlet and the outlet to receive the ultrasonic waves passing through the sleeve; a digitizer for digitizing an analog signal generated by the receiver; and an analyzer for storing and analyzing data transmitted from the digitizer.

Description

Non-destructive testing device for verifying sleeve filling degree and non-destructive testing method using the same

[0001] The present invention relates to a non-destructive testing device for verifying sleeve filling degree and a non-destructive testing method using the same. More specifically, it relates to a technology for analyzing the filling degree of joint hardware used in the PC construction method using a non-destructive testing method, deriving analysis data therefrom, and determining the filling rate using the analysis data.

[0002]

[0003] The Precast Concrete (PC) method is a construction technique in which core structural components of a building are standardized, manufactured in a factory, and then transported to the construction site for assembly. Furthermore, because components are fabricated in advance, it is possible to reduce labor costs at the construction site, and by minimizing the impact of weather conditions, it offers significant benefits in shortening the construction period.

[0004] At this time, for joining structural members in the PC method, a wet method is generally used in which grout (a material used to fill gaps between structures or to reinforce) is filled into the joint fittings (spiral corrugated pipes, sleeves) inside the structural members at the site.

[0005] Unlike structural members that are prefabricated in a factory, joining structural members is a labor-intensive process carried out on-site, so the quality of the grout filling can vary depending on the precision of the on-site construction.

[0006] Accordingly, since there is a risk that structural and construction site stability may deteriorate depending on the quality of the grout filling, quality inspection and construction management of grout filling at joints in the PC method are essential.

[0007] The grout inside the joint hardware may not fully guarantee internal density due to the complex internal structure of the joint hardware, deformation of the reinforcing bars, and deterioration of the grout quality.

[0008] According to current standards (Domestic: KCS, EXCS; International: PCI, JASS10), the quality inspection of grout filling in PC joints is primarily conducted through visual inspection, which is a qualitative evaluation, and only external inspection of the PC joint is permitted.

[0009] According to prior domestic and international studies, camera imaging, concrete surface hardness, elastic wave, and acoustic emission techniques have been applied to inspect grout filling levels; however, these methods have limitations, such as the inability to inspect after grout filling and the cumbersome measurement process.

[0010] Therefore, to avoid the application of impractical destructive testing for the internal inspection of PC joints and to enhance the structural safety of the construction method and ensure quality, it is necessary to apply non-destructive testing techniques.

[0011] Ultrasonic techniques are fundamental non-destructive methods that transmit ultrasound through a medium and receive the passing signals. They offer excellent field applicability through real-time measurement and enable the detection of defects within the medium, making them suitable for inspecting the filler content of PC joints.

[0012] In addition, by adjusting the size of the measurement sensor, a site-customized design is possible to enable measurements at small openings in PC joints.

[0013] It is assessed that it will be possible to propose quality control indicators for PC structures based on a large amount of field data following on-site measurements.

[0014] In Korean Registered Patent No. 10-1113660 (Title of Invention: System for Monitoring the Integrity of Members of a Building Structure), a vibration generating device that generates non-destructive testing vibrations in a building structure to determine whether the building structure is damaged and the extent of damage; an acceleration sensor installed on each floor of the building structure to detect vibrations of each floor generated by the vibration generating device; a floor displacement / acceleration calculation unit that calculates floor displacement / acceleration by calculating a frequency response function in response to vibrations detected by the acceleration sensor; a stiffness calculation unit by member group that calculates stiffness by member group based on the floor displacement / acceleration of the building structure calculated by the floor displacement / acceleration calculation unit; a deformation gauge installed on a target member selected among member groups or members forming the building structure to detect bending deformation of the target member; and a bending deformation calculation unit that calculates the bending deformation of the target member in response to the bending deformation detected by the deformation gauge. A structural integrity monitoring system for each member of a building structure is disclosed, comprising a target member stiffness calculation unit that calculates the stiffness of the target member based on the bending deformation calculated by the bending deformation calculation unit.

[0015] (Prior Art Literature)

[0016] Republic of Korea Registered Patent No. 10-1113660

[0017]

[0018] The objective of the present invention, which aims to solve the aforementioned problems, is to provide a technology that analyzes the filling degree of joint fittings used in the PC construction method using a non-destructive testing method, derives analysis data therefrom, and determines the filling rate using the analysis data.

[0019] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0020]

[0021] The configuration of the present invention for achieving the above-mentioned purpose comprises: a transducer connected to either an injection port or an discharge port formed in a sleeve for a PC (Precast Concrete) construction method, for emitting ultrasonic waves into the interior of the sleeve; a receiver connected to the other of the injection port and the discharge port, for receiving ultrasonic waves that have passed through the interior of the sleeve; a digitizer for digitizing an analog signal generated by the receiver; and an analysis unit for storing and analyzing data transmitted from the digitizer.

[0022] In an embodiment of the present invention, the transducer may be provided with an excitation part that is formed protruding from one part of the transducer and emits ultrasound.

[0023] In an embodiment of the present invention, the receiver may have a receiving part formed to protrude from a part of the receiver and receive ultrasound.

[0024] In an embodiment of the present invention, the receiving unit may comprise a P-wave receiver for receiving a P-wave; and an S-wave receiver for receiving an S-wave.

[0025] In an embodiment of the present invention, a pre-amplifier formed between the receiver and the data converter to amplify the signal of the receiver may be further included.

[0026] In an embodiment of the present invention, a function generator that generates waveform information and transmits it to the converter may be further included.

[0027] In an embodiment of the present invention, grout may be filled inside the joint fitting.

[0028] The configuration of the present invention for achieving the above-mentioned purpose comprises: a spectrum extraction step in which a measurement signal graph is generated in the analysis unit using data transmitted from the data converter, and then a spectrum graph is extracted through frequency analysis; an energy distribution derivation step in which a plurality of spectrum graphs are stacked in the analysis unit, and an energy distribution map is derived, which is a distribution map of the energy values ​​of each of the plurality of spectrum graphs in a preset frequency band; and a filling rate derivation step in which learning is performed on the energy distribution map in the analysis unit, and the filling rate of the grout within the joint is derived.

[0029] In an embodiment of the present invention, a clustering algorithm may be used to perform machine learning in the step of deriving the charging rate.

[0030] In an embodiment of the present invention, the spectrum extraction step may include: a frequency graph extraction step for extracting a plurality of frequency graphs by frequency analysis of the measurement signal graph; and a spectrum graph forming step for extracting the spectrum graph by color differentiation according to amplitude in each of the plurality of frequency graphs.

[0031] In an embodiment of the present invention, in the frequency graph extraction step, frequency analysis of the measured signal graph can be performed through a Fourier transform.

[0032] In an embodiment of the present invention, in the energy distribution derivation step, a number is assigned to each of the plurality of spectrum graphs' unit color elements, and the energy distribution diagram may be a graph of the relationship between the energy and the number of the unit color elements.

[0033]

[0034] The effect of the present invention according to the above configuration is that when using the non-destructive inspection device of the present invention, the quality of grout filling and the presence of defects in the PC joint can be analyzed immediately in a simple manner by connecting the transducer and the receiver to the joint hardware and operating it, thereby enabling an improvement in construction quality and a reduction in maintenance costs.

[0035] Furthermore, the effect of the present invention is that precise analysis of the grout filling rate within the joint hardware is possible by extracting multiple frequencies from measurement signal data and performing analysis using respective spectrum graphs.

[0036] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description of the invention or the claims.

[0037]

[0038] FIG. 1 is a schematic diagram of an inspection method of a non-destructive inspection device according to one embodiment of the present invention.

[0039] FIG. 2 is a schematic diagram of the configuration of a non-destructive inspection device according to one embodiment of the present invention.

[0040] FIG. 3 is a schematic diagram of a converter and a receiver according to one embodiment of the present invention.

[0041] FIG. 4 is a graph generated by a data converter according to one embodiment of the present invention and a frequency graph obtained by changing it.

[0042] FIG. 5 is a plurality of frequency graphs according to one embodiment of the present invention.

[0043] FIGS. 6 and FIGS. 7 are graphs and images related to spectrum graph extraction according to one embodiment of the present invention.

[0044] Figure 8 is an image related to the cumulative spectrum according to the filling rate of a joint fitting according to one embodiment of the present invention.

[0045] FIGS. 9 to 11 are cumulative spectra and related energy distribution diagrams according to the filling rate of a joint fitting according to one embodiment of the present invention.

[0046] FIG. 12 is a distribution map generated for each parameter using a cumulative spectrum according to an embodiment of the present invention.

[0047] FIG. 13 is a 3D scatter plot using an energy distribution map according to one embodiment of the present invention.

[0048] FIGS. 14 to 17 are graphs and images related to machine learning analysis of the results of deriving the filling rate according to one embodiment of the present invention.

[0049]

[0050] A most preferred embodiment according to the present invention comprises: a transducer connected to either an injection port or an discharge port formed in a sleeve for a precast concrete (PC) construction method and emitting ultrasonic waves into the interior of the sleeve; a receiver connected to the other of the injection port and the discharge port and receiving ultrasonic waves that have passed through the interior of the sleeve; a digitizer that digitizes an analog signal generated by the receiver; and an analysis unit that stores and analyzes data transmitted from the digitizer.

[0051]

[0052] The present invention will be described below with reference to the attached drawings. However, the present invention may be implemented in various different forms and is therefore not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification have been given similar reference numerals.

[0053] Throughout the specification, when it is stated that a part is "connected (connected, in contact, combined)" with another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other members interposed between them. Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components.

[0054] The terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0055] Hereinafter, the present invention will be described in detail with reference to the attached drawings.

[0056]

[0057] FIG. 1 is a schematic diagram of an inspection method of a non-destructive inspection device according to one embodiment of the present invention, FIG. 2 is a schematic diagram of the configuration of a non-destructive inspection device according to one embodiment of the present invention, and FIG. 3 is a schematic diagram of a converter (100) and a receiver (200) according to one embodiment of the present invention.

[0058] As shown in FIGS. 1 to 3, the non-destructive inspection device of the present invention comprises: a transducer (100) connected to either an injection port (31) or an discharge port (32) formed in a sleeve (30) for a PC (Precast Concrete) construction method, which emits ultrasonic waves into the interior of the sleeve (30); a receiver (200) connected to the other of the injection port (31) and the discharge port (32), which receives ultrasonic waves that have passed through the interior of the sleeve (30); a digitizer (Data Acquisition) (330) which digitizes an analog signal generated by the receiver (200); and an analysis unit (340) which stores and analyzes data (measurement data) transmitted from the data digitizer.

[0059] For convenience of explanation, as an example, each drawing discloses that the converter (100) is connected to the injector (31) and the receiver (200) is connected to the discharge port (32).

[0060] The joint hardware (30) may be provided with: a joint hardware body (33) having a cylindrical shape with an internal space formed therein and corrugations formed on the side wall to form an uneven surface on the inner and outer sides; an injection port (31) formed on the side wall of one end portion of the joint hardware body (33) and providing a passage connecting the internal space of the joint hardware body (33) to the outside; and a discharge port (32) formed on the side wall of the other end portion of the joint hardware body (33) and providing a passage connecting the internal space of the joint hardware body (33) to the outside.

[0061] Grout (22) can be filled inside the joint fitting (30). Specifically, the grout (22) can be filled into the internal space of the joint fitting body (33). Additionally, the joint fitting (30) is used for assembling concrete members (10), and a reinforcing bar (21) for assembly can penetrate each concrete member (10) and simultaneously penetrate the joint fitting (30) to pass through the internal space of the joint fitting (30).

[0062] At this time, as the grout (22) hardens, it combines with the reinforcing bar (21), and by this, the reinforcing bar (21) is fixed to each concrete member (10), thereby allowing the concrete members (10) to be joined together.

[0063]

[0064] The transducer (100) may be provided with an excitation part (110) that is formed protruding from a part of the transducer (100) and emits ultrasound.

[0065] The excitation unit (110) may be equipped with a vibrator (111) that generates ultrasonic waves; and an excitation coupling member (112) that is inserted into and fitted into the injection port (31) of the joint fitting (30).

[0066] The passage of the injection port (31) can be formed in the shape of a circular hole, and the vibration coupling member (112) can be formed in a cylindrical shape corresponding to the shape of the injection port (31), and such a vibration coupling member (112) can be fitted into the passage of the injection port (31).

[0067] The diameter of the vibrator (111) having a cylindrical shape may be smaller than the diameter of the excitation coupling member (112), and when the excitation coupling member (112) is coupled to the injection port (31), the end of the vibrator (111) may come into contact with the grout (22) in the internal space of the joint fitting (30).

[0068] Additionally, the non-destructive inspection device of the present invention may further include a function generator (310) that generates waveform information and transmits it to a converter (100). The function generator (310) transmits a signal of waveform information to the converter (100) so that the vibrator (111) can generate ultrasound with the corresponding waveform.

[0069] Specifically, a motor (or actuator) that generates ultrasonic waves may be formed inside the excitation unit (110), and the motor is connected to a vibrator (111). A signal from the function generator (310) is transmitted to the motor, and the motor operates to transmit vibrations to the vibrator (111), thereby generating ultrasonic waves of the corresponding waveform by the vibrator (111).

[0070] In this case, the waveform consists of two types of square waves and sine waves, and the center frequency f0 can be 50 Hz. The formulas for each waveform are as shown in [Equation 1] and [Equation 2] below.

[0071] [Formula 1]

[0072]

[0073] [Equation 2]

[0074]

[0075]

[0076] The receiver (200) may be provided with a receiving unit (210) that is formed protruding from a part of the receiver (200) and receives ultrasound. Additionally, the receiving unit (210) may be provided with a P-wave receiver (200) that receives P-waves; and an S-wave receiver (200) that receives S-waves.

[0077] Additionally, the receiving unit (210) may further comprise a receiving coupling member (212) that is inserted into and fitted into the discharge port (32) of the joint fitting (30); and a probe (211) that has the above-mentioned P-wave receiver (200) and S-wave receiver (200) inside and contacts the grout (22) of the joint fitting (30).

[0078] P-waves and S-waves can be generated as ultrasonic waves pass through the grout (22) by the operation of the vibrator (111) as described above.

[0079] The passage of the discharge port (32) can be formed in the shape of a circular hole, and the receiving coupling member (212) can be formed in a cylindrical shape corresponding to the discharge port (32), and such a receiving coupling member (212) can be fitted into the passage of the discharge port (32).

[0080] The diameter of each of the P-wave receiver (200) and S-wave receiver (200) having a cylindrical shape may be smaller than that of the receiving coupling member (212), and when the receiving coupling member (212) is coupled to the discharge port (32), the end of each receiver (200) may come into contact with the grout (22) in the internal space of the joint fitting (30).

[0081] As described above, when performing non-destructive measurement, the excitation coupling member (112) is fitted into the injection port (31) and fixed, and the receiving coupling member (212) is fitted into the discharge port (32) and fixed, and at the same time, the ends of the vibrator (111) and each receiving member come into contact with the grout (22), thereby making it easy to detect ultrasonic waves passing through the grout (22) in the internal space of the sealed joint fitting (30).

[0082] In addition, by fixing the excitation coupling member (112) and the receiving coupling member (212), the positions of the vibrator (111) and each receiver (200) are stably maintained, so that ultrasonic detection can be performed precisely.

[0083]

[0084] The non-destructive inspection device of the present invention may further include a pre-amplifier (320) formed between a receiver (200) and a data converter to amplify the signal of the receiver (200). With such a structure, the ultrasonic waves generated by the operation of the vibrator (111) pass through the grout (22) in the internal space of the joint fitting (30), and then the P-wave and S-wave can be detected by each receiver (200).

[0085] Then, each signal detected by the P-wave receiver (200) and the S-wave receiver (200) is transmitted to an amplifier (320), and the amplifier (320) can amplify each signal and transmit it to a data converter (330). At this time, the signal transmitted from the amplifier (320) may be an analog signal, and the data converter (330) can convert the analog signal into a digital signal and then transmit the digital signal to an analysis unit (340).

[0086]

[0087] The analysis unit (340) can generate amplitude-time data and a graph thereof using the digital signal as described above, and can analyze the filling rate of the grout within the joint fitting (30) using this. Below, the non-destructive inspection method of the present invention related thereto will be described in detail.

[0088] In the non-destructive inspection method of the present invention, a spectrum extraction step; an energy distribution derivation step; and a filling rate derivation step may be performed.

[0089] FIG. 4 is a graph generated by a data converter (330) according to one embodiment of the present invention and a frequency graph obtained by changing it, FIG. 5 is a plurality of frequency graphs according to one embodiment of the present invention, and FIG. 6 and FIG. 7 are graphs and images related to spectrum graph extraction according to one embodiment of the present invention.

[0090] Specifically, FIG. 4(a) is a measurement signal graph generated using data transmitted from a data converter (330), and FIG. 4(b) is a frequency graph obtained after performing a Fourier transform on the measurement signal graph.

[0091] In addition, Fig. 6(a) is a frequency graph, Fig. 6(b) is a spectrum graph obtained by transforming the frequency graph, and Fig. 7 is an image comparing the frequency graph and the spectrum graph by overlaying them.

[0092] As shown in FIGS. 4 to 7, in the spectrum extraction step, a measurement signal graph is generated in the analysis unit (340) using data transmitted from the data converter (330), and then a spectrum graph can be extracted through frequency analysis.

[0093] At this time, while the noise is a low frequency of 1 to 4 kHz, the ultrasonic signal is a high frequency of 20 to 100 kHz, so the signal and noise are clearly distinguishable, making it easy to perform analysis of the ultrasonic signal band.

[0094] Information regarding the type of grout may be transmitted to the analysis unit (340) in advance, and in each of FIGS. 6 to FIGS. 11, NN19 may indicate the type of material of the grout, and the number following NN19 (100, 80, or 50) may indicate the filling rate.

[0095] Here, the spectrum extraction step may include a frequency graph extraction step; and a spectrum extraction step.

[0096] In the frequency graph extraction step, multiple frequency graphs can be extracted by frequency analysis of the measured signal graph.

[0097] Here, frequency analysis of the measured signal graph can be performed using the Fourier transform. Since frequency decomposition by the Fourier transform is a conventional technique, a detailed explanation is omitted.

[0098] That is, the measurement signal graph is a frequency-related graph generated in the data converter (330) before the Fourier transform, and the frequency graph is a graph generated by the Fourier transform.

[0099] As shown in Fig. 4(b), various n-th order modes can occur over the range of 0 to 1001 Hz, and as shown in Fig. 5, multiple frequency graphs can be generated by Fourier transform decomposition of the measured signal graph.

[0100] In the spectrum graph formation step, a spectrum graph can be extracted by color-coding according to amplitude in each of the multiple frequency graphs. As shown in FIGS. 6 and 7, relative amplitudes in a single frequency graph can be distinguished by expressing them in color. In FIGS. 6 and 7, the amplitude is normalized to a range of 0 to 1 and distinguished by color for each step, but the numbers for the range can also be displayed as 0 to 100.

[0101] A spectrum graph can be extracted using a single frequency graph.

[0102]

[0103] FIG. 8 is an image related to the cumulative spectrum according to the filling rate of a joint fitting (30) according to one embodiment of the present invention, and FIG. 9 to 11 are distribution diagrams related to the cumulative spectrum according to the filling rate of a joint fitting (30) according to one embodiment of the present invention.

[0104] Specifically, Figures 8(a) and 8(b) are for the same cumulative spectrum, and Figure 8(b) shows the relative high and low energy levels in the 19–20 Hz band.

[0105] In addition, Figure 9(a) shows the selection of the 19–20 Hz band in the cumulative spectrum, and Figure 9(b) shows the energy distribution diagram for the energy distribution in the 19–20 Hz band in the cumulative spectrum.

[0106] In addition, Figure 10 (a) shows the selection of the 24–26 Hz band in the cumulative spectrum, and Figure 10 (b) is an energy distribution diagram of the energy distribution in the 24–26 Hz band in the cumulative spectrum.

[0107] In addition, Figure 11 (a) shows the selection of the 33–34 Hz ​​band in the cumulative spectrum, and Figure 11 (b) is an energy distribution diagram of the energy distribution in the 33–34 Hz ​​band in the cumulative spectrum.

[0108] In the energy distribution derivation step, the analysis unit (340) can stack and arrange multiple spectrum graphs, and derive an energy distribution diagram which is a distribution diagram of the energy values ​​of each of the multiple spectrum graphs in a preset frequency band. At this time, the multiple spectrum graphs can be stacked to form a cumulative spectrum.

[0109] Here, a number is assigned to each unit color element of a plurality of spectrum graphs, and the energy distribution graph may be a graph of the relationship between energy and the number of the unit color element.

[0110] And, the energy in the energy distribution diagram can be calculated by the following [Equation 3].

[0111] [Equation 3]

[0112]

[0113] That is, [Equation 3] is the value obtained by dividing the sum of the amplitudes of the 1~100kHz range in a single frequency graph by the sum of the specific range (ab kHz).

[0114] At this time, the unit color may be a color in a unit frequency band area in a spectrum graph for a single frequency graph. Specifically, the unit frequency band area may be 1 kHz. However, although the embodiments are not limited thereto, a cumulative spectrum based on this is disclosed in FIGS. 8 to 11.

[0115] As shown in FIG. 8, a plurality of spectrum graphs can be accumulated to form a cumulative spectrum. After obtaining a measurement signal graph for each of the different joints (30), namely the joint (30) with a 100% filling rate, the joint (30) with an 80% filling rate, and the joint (30) with a 50% filling rate in terms of grout filling rate, a spectrum graph for each can be obtained through the process described above, and the cumulative spectrum can be generated by accumulating such plurality of spectrum graphs.

[0116] However, using data of different filling rates as described above is intended to explain and verify the principle of the non-destructive inspection method of the present invention, and in practice, the filling rate of the joint (30) can be determined by using the cumulative spectrum obtained after performing a measurement on the joint (30) of an unknown filling rate.

[0117] As shown in Fig. 9(a), the preset frequency band can be set to 19~20Hz, and a number (Specimen index) can be assigned to a plurality of unit color bodies in that band, and a different color can be formed at the amplitude of each of the plurality of unit color bodies.

[0118] And, as seen in Fig. 9(b), energy is formed differently according to the unit color body distinguished by each number, and an energy distribution map can be generated by displaying this as a graph.

[0119] As shown in Fig. 10 (a), the preset frequency band can be set to 24 to 26 Hz, and a number (Specimen index) can be assigned to a plurality of unit color bodies in that band, and a different color can be formed at the amplitude of each of the plurality of unit color bodies.

[0120] And, as seen in Fig. 10 (b), energy is formed differently according to the unit color body distinguished by each number, and an energy distribution map can be generated by displaying this as a graph.

[0121] As shown in Fig. 11 (a), the preset frequency band can be set to 33~34 Hz, and a number (Specimen index) can be assigned to a plurality of unit color bodies in that band, and a different color can be formed at the amplitude of each of the plurality of unit color bodies.

[0122] And, as seen in Fig. 11 (b), energy is formed differently according to the unit color body distinguished by each number, and an energy distribution map can be generated by displaying this as a graph.

[0123] In each of FIG. 9(b), FIG. 10(b) and FIG. 11(b), the unit color number can be set in the cumulative spectrum for each fill rate, and accordingly, the number of any unit color in the 100% fill rate cumulative spectrum and the number of any unit color in the 80% or 50% fill rate cumulative spectrum may be the same.

[0124] In the analysis unit (340), machine learning can be performed using data on the cumulative spectrum according to the type of grout and the filling rate of each grout as training data. As shown in FIGS. 8 to 10, the color difference of the cumulative spectrum for each filling rate, i.e., frequency bands with strong signal sensitivity, can be extracted, and the corresponding frequency bands can be used when analyzing the grout.

[0125] Specifically, when the type of grout in the joint fitting (30) being measured is input as NN19 in the analysis unit (340), the process of deriving the filling rate can be performed by analyzing the bands of 19~20Hz, 24~26Hz, and 33~34Hz respectively as described above.

[0126] In other words, there can be three or more frequency bands set. This is also suitable for analysis using machine learning as described below.

[0127]

[0128] FIG. 12 is a distribution map generated for each parameter using a cumulative spectrum according to one embodiment of the present invention, and FIG. 13 is a 3D scatter plot using an energy distribution map according to one embodiment of the present invention.

[0129] Specifically, FIG. 12(a) is a distribution graph related to energy (Parameter 2) at 19-20 Hz and energy (Parameter 1) at 33-34 Hz, and FIG. 12(b) is a distribution graph related to energy (Parameter 1) at 33-34 Hz ​​and energy (Parameter 3) at 24-26 Hz.

[0130] And, Fig. 13 is a 3D scatter plot related to energy at 33-34 Hz ​​(Parameter 1), energy at 19-20 Hz (Parameter 2), and energy at 24-26 Hz (Parameter 3).

[0131] FIGS. 14 to 17 are graphs and images related to machine learning analysis of the results of deriving the filling rate according to one embodiment of the present invention.

[0132] Specifically, FIG. 14 (a) is a distribution scatter plot showing only the distribution of the above-mentioned 3D scatter plot, and FIG. 14 (b) is a clustering scatter plot after performing clustering of the clustering algorithm on the data of the above-mentioned distribution scatter plot.

[0133] In Fig. 14, f19 represents data in the 19-20Hz band, f24 represents data in the 24-26Hz band, and f33 represents data in the 33-34Hz band.

[0134] Figure 15 is a Confusion Matrix based on machine learning. Here, the vertical axis represents the actual filling rate (Actual Label) and the horizontal axis represents the predicted filling rate (Predicted Label).

[0135] Specifically, FIG. 16 (a) is a distribution scatter plot showing only the distribution of the above-mentioned 3D scatter plot, and FIG. 16 (b) is a clustering scatter plot after performing clustering of the clustering algorithm on the data of the above-mentioned distribution scatter plot.

[0136] Unlike in Fig. 14, in Fig. 16, data related to the 50% charge rate and data related to the 80% charge rate are processed as a single cluster and distinguished from data related to the 100% charge rate.

[0137] Figure 17 is a Confusion Matrix based on machine learning. Here, the vertical axis represents the actual filling rate (Actual Label) and the horizontal axis represents the predicted filling rate (Predicted Label).

[0138] As shown in FIGS. 12 to 17, in the step of deriving the filling rate, the analysis unit (340) performs learning on the energy distribution map and can derive the filling rate of the grout within the joint fitting (30). Here, a clustering algorithm can be used to perform machine learning.

[0139] As described above, a distribution scatter plot can be generated using multiple energy distribution plots, and a clustering scatter plot can be formed by applying a clustering algorithm to such a distribution scatter plot to perform clustering.

[0140] The analysis unit (340) can form a plurality of clustering scatter plots using each of the measurement signal graphs with known charging rates, and perform machine learning using the data therefrom as training data.

[0141] And, when a measurement signal graph for a measurement target whose filling rate is unknown is obtained, the analysis unit (340) derives a clustering scatter plot through the process as described above, and can derive the filling rate of the grout in the joint fitting (30) by performing machine learning on the clustering scatter plot derived in this way.

[0142] That is, when a clustering scatter plot is obtained using a measurement signal graph for a measurement target whose filling rate is unknown, the analysis unit (340) performs an analysis of the parameters of each axis (energy of preset frequency wavelength bands) and the position of the dot cluster in the clustering scatter plot, and can determine the filling rate of the grout using this.

[0143] When using the non-destructive inspection method of the present invention as described above, as shown in FIGS. 15 and 17, cases where the filling rate is 100% and cases where the filling rate is not 100% are clearly distinguished in the Confusion Matrix. Accordingly, it can be confirmed that when using the non-destructive device and the non-destructive method of the present invention, defects that are not at a 100% filling rate can be clearly identified.

[0144] When using the non-destructive method of the present invention as described above, a plurality of frequencies are extracted from the measurement signal data and an analysis is performed using each spectrum graph, thereby enabling a precise analysis of the grout filling rate within the joint fitting (30).

[0145]

[0146] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0147] The scope of the present invention is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention.

[0148] (Explanation of symbols)

[0149] 10: Concrete member 21: Reinforcement bar

[0150] 22: Grout 30: Joint hardware

[0151] 31: Inlet 32: Outlet

[0152] 33: Joint hardware body 100: Converter

[0153] 110: Excitation part 111: Vibrator

[0154] 112: Excitation coupling member 200: Receiver

[0155] 210: Receiver 211: Probe

[0156] 212: Receiver coupling member 310: Function generator

[0157] 320: Amplifier 330: Data converter

[0158] 340: Analysis Department

[0159]

[0160]

Claims

1. A transducer connected to either an injection port or an discharge port formed in a sleeve for the PC (Precast Concrete) construction method, which emits ultrasonic waves into the interior of the sleeve; A receiver connected to the other of the injection port and the discharge port to receive ultrasonic waves that have passed through the interior of the joint fitting; A digitizer that digitizes the analog signal generated by the receiver; and A non-destructive inspection device for verifying sleeve filling degree, characterized by including an analysis unit that stores and analyzes data transmitted from the above-mentioned data converter.

2. In Claim 1, A non-destructive inspection device for verifying sleeve filling degree, characterized in that the above-described transducer is formed protruding from a part of the transducer and has an excitation part that emits ultrasound.

3. In Claim 1, A non-destructive inspection device for verifying sleeve filling degree, characterized in that the receiver is formed protruding from a part of the receiver and has a receiving part that receives ultrasound.

4. In Claim 3, The above receiving unit is, A P-wave receiver for receiving P-waves; and A non-destructive inspection device for verifying sleeve filling degree, characterized by having an S-wave receiver that receives S-waves.

5. In Claim 1, A non-destructive inspection device for verifying sleeve filling degree, characterized by further including an amplifier (pre-amplifier) ​​formed between the receiver and the data converter to amplify the signal of the receiver.

6. In Claim 1, A non-destructive inspection device for verifying sleeve filling degree, further comprising a function generator that generates waveform information and transmits it to the converter.

7. In Claim 1, A non-destructive inspection device for verifying sleeve filling degree, characterized in that grout is filled inside the above-mentioned joint fitting.

8. A non-destructive testing method using a non-destructive testing device for verifying sleeve filling degree according to Claim 1, A spectrum extraction step in which a measurement signal graph is generated in the analysis unit using data transmitted from the data converter above, and then a spectrum graph is extracted through frequency analysis; In the analysis unit above, an energy distribution derivation step of stacking a plurality of spectrum graphs and deriving an energy distribution map which is a distribution map of the energy values ​​of each of the plurality of spectrum graphs in a preset frequency band; and A non-destructive inspection method characterized by including: a filling rate derivation step in which, in the analysis unit, learning is performed on the energy distribution map and the filling rate of the grout within the joint is derived.

9. In Claim 8, A non-destructive inspection method characterized by using a clustering algorithm for performing machine learning in the above-mentioned filling rate derivation step.

10. In claim 8, The spectrum extraction step described above is, A frequency graph extraction step for extracting a plurality of frequency graphs by frequency analysis of the above-mentioned measurement signal graph; and A non-destructive inspection method characterized by including a spectrum graph forming step of extracting the spectrum graph by color-distinguishing according to amplitude in each of the plurality of frequency graphs.

11. In Claim 9, A non-destructive inspection method characterized in that, in the frequency graph extraction step, frequency analysis of the measurement signal graph is performed through a Fourier transform.

12. In Claim 9, A non-destructive inspection method characterized in that, in the energy distribution derivation step, a number is assigned to each of the unit color elements of the plurality of spectrum graphs, and the energy distribution graph is a graph of the relationship between the energy and the number of the unit color elements.

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