WO2002040959A1 - Dispositif et procede de mesure et de diagnostic acoustiques au moyen d'une force electromagnetique pulsee - Google Patents
Dispositif et procede de mesure et de diagnostic acoustiques au moyen d'une force electromagnetique pulsee Download PDFInfo
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- WO2002040959A1 WO2002040959A1 PCT/JP2001/009742 JP0109742W WO0240959A1 WO 2002040959 A1 WO2002040959 A1 WO 2002040959A1 JP 0109742 W JP0109742 W JP 0109742W WO 0240959 A1 WO0240959 A1 WO 0240959A1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/44—Processing the detected response signal, e.g. electronic circuits specially adapted therefor
- G01N29/46—Processing the detected response signal, e.g. electronic circuits specially adapted therefor by spectral analysis, e.g. Fourier analysis or wavelet analysis
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
- G01N17/006—Investigating resistance of materials to the weather, to corrosion, or to light of metals
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/22—Details, e.g. general constructional or apparatus details
- G01N29/24—Probes
- G01N29/2412—Probes using the magnetostrictive properties of the material to be examined, e.g. electromagnetic acoustic transducers [EMAT]
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/38—Concrete; ceramics; glass; bricks
- G01N33/383—Concrete, cement
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/01—Indexing codes associated with the measuring variable
- G01N2291/015—Attenuation, scattering
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/024—Mixtures
- G01N2291/02458—Solids in solids, e.g. granules
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/025—Change of phase or condition
- G01N2291/0255—(Bio)chemical reactions, e.g. on biosensors
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/028—Material parameters
- G01N2291/02827—Elastic parameters, strength or force
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/028—Material parameters
- G01N2291/02854—Length, thickness
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/04—Wave modes and trajectories
- G01N2291/042—Wave modes
- G01N2291/0423—Surface waves, e.g. Rayleigh waves, Love waves
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/10—Number of transducers
- G01N2291/102—Number of transducers one emitter, one receiver
Definitions
- the present invention relates to an acoustic diagnostic / measurement device using pulsed electromagnetic force and a diagnostic / measurement method for a structure composed of a conductor and a non-conductive material covering the conductor, and for example, relates to corrosion and adhesion of reinforcing steel in reinforced concrete, Diagnosis or measurement of the position of reinforcing bars, diameter of reinforcing bars, presence / absence of reinforcing bars, locations of tears, and locations of water pipes buried in the soil, and fixing of conductors fixed with fasteners
- the present invention relates to a condition diagnosis method. Background art
- the location of the rebar and the diameter of the rebar are used for the purpose of strength evaluation, service life evaluation, or determination of construction procedures.
- an X-ray imaging method in which a structure is sandwiched between an X-ray generator and a film, an ultrasonic generator is applied to a concrete surface, and the reflected ultrasonic waves are applied
- Ultrasound diagnostic method to detect and judge, percussion method to judge the surface by hitting the surface with a hammer, etc.
- infrared imaging method to irradiate infrared to the surface
- microwave method to irradiate microwave from the surface
- the ultrasonic survey method irradiates ultrasonic waves from the surface of reinforced concrete and searches for the position of the reinforcing bars from the ultrasonic waves reflected from the reinforcing bars.However, the interior of the concrete contains gravel and is discontinuous due to bubbles and the like. Because the layers are dense, ultrasonic waves are attenuated and scattered, making analysis very difficult.
- the infrared imaging method and the microphone mouth wave method can measure only the relatively surface of a structure because infrared and microphone mouth waves are rapidly attenuated by concrete.
- an acoustic diagnostic method in which sound generated by elastic energy released when a structure is deformed or destroyed is detected and analyzed to diagnose the degree of corrosion of the structure.
- a method is known in which an AE (acoustic emission) sensor is attached to a structure and the AE is measured for a long time, and the sound (AE) generated suddenly or accidentally due to corrosion destruction is known.
- AE acoustic emission
- this method requires continuous observation for a long time or requires an excessive load, and is not always suitable for diagnosing structural corrosion.
- structures consisting of tensioned conductors and non-conductors that cover the conductors, such as prestressed concrete, that is, bridges using this method, concrete utility poles, and concrete sleepers, have elasticity. Reinforcing bars in tension to increase their strength are embedded in concrete, and may break after prolonged use.
- Conductor pipes buried in non-conductors for example, in civil engineering works and building works where it is necessary to drive piles into the soil, water pipes and gas pipes buried in the soil are required. Need to know the location. Conventionally buried using metal detectors, ultrasonic detectors, etc. Although the position is measured, these devices are complex, require a high degree of expertise in handling, there is no easy and reliable way to know the location of the buried site, and there is no time to dig and check it. Such a method was often adopted.
- a bolt nut is used in the case of a structure in which a conductor is fixed to a conductor with fasteners.
- a structure such as a road bridge constructed by fixing an iron plate and an iron plate with a bolt nut
- a bolt nut is used in the case of a structure in which a conductor is fixed to a conductor with fasteners. It is necessary to regularly inspect the tightening condition of the kit to ensure safety.
- the bolts and nuts are huge, and the tightening force is so large that the operator can perform a diagnosis manually using a torque wrench or the like. Did not. For this reason, conventionally, large-scale dedicated machines for inspection were required, and inspection had to be carried out with the bridge closed.
- the present invention reliably and non-destructively determines the degree of corrosion, adhesion, fogging depth, and diameter of a conductor of a structure including a conductor and a non-conductor that covers the conductor.
- Diagnosis / measurement equipment for example, non-destructive diagnosis / measurement of the degree of corrosion of reinforcing steel in reinforcing concrete, adhesion between reinforcing steel and concrete, and concrete overhang depth of concrete in concrete / measurement
- the primary purpose is to provide a device capable of performing such operations.
- a second object is to provide a device for reliably measuring.
- the degree of corrosion, adhesion, and position of the conductor of a structure consisting of a conductor and a non-conductor that covers the conductor can be determined or diagnosed based on the minute vibration distribution over the entire surface and the manner of propagation of the vibration. It is a third object of the present invention to provide a device capable of non-destructively measuring, for example, the degree of corrosion of reinforcing steel in reinforced concrete, the adhesion between the reinforcing steel and the concrete, and the position of the reinforcing steel at a high level. .
- a fourth object of the present invention is to provide a method for diagnosing and measuring the degree of corrosion of reinforcing steel and the adhesive strength between the reinforcing steel and the concrete.
- a fifth object is to provide a method that can be measured.
- a method for reliably and non-destructively measuring the position of a conductor in a structure composed of a conductor and a non-conductor covering a conductor, for example, in a non-destructive manner, such as the degree of corrosion of reinforcing steel in reinforced concrete It is a sixth object of the present invention to provide a method capable of highly diagnosing and measuring the adhesive force between concrete and concrete, and the position of a reinforcing bar from the minute vibration distribution and the vibration propagation mode over the entire surface.
- a method for measuring the diameter or cover depth of a conductor of a structure composed of a conductor and a non-conductor covering a conductor for example, a method of measuring the diameter or cover depth of a reinforcing bar of reinforced concrete.
- the seventh purpose is to provide.
- a method to reliably and non-destructively diagnose and measure the position of a conductor buried in a non-conductor such as a method to diagnose and measure the burial position of water pipes and gas pipes buried in soil.
- the ninth purpose is to provide.
- a tenth objective is to provide a method for measuring the presence or absence or the position of the used bridge, concrete utility pole or concrete sleeper. Disclosure of the invention
- the acoustic diagnostic / measuring device based on pulsed electromagnetic force is mounted on a surface of a structure comprising a conductor and a non-conductor covering the conductor. It has a coil, a power supply unit that supplies a current pulse to the coil, an acoustic transducer attached to the surface of the structure or a conductor exposed from the non-conductor, and a measurement unit that measures the output waveform of the acoustic transducer. It is characterized by diagnosing or measuring the corrosion of conductors, adhesion, fogging depth and diameter.
- the structure to be measured is reinforced concrete
- the rebar Since the rebar is directly excited by the field pulse, sound is generated from the position of the rebar as a sound source, and this sound propagates to the surface of the structure.
- the acoustic waveform propagating on the surface of the structure changes according to the degree of corrosion and the adhesion of the reinforcing bar, and the degree of corrosion and the strength of the adhesion can be diagnosed and measured from the analysis of the acoustic waveform.
- the amplitude of the acoustic waveform changes according to the reinforcing bar diameter and the covering depth, so if the reinforcing bar depth is known, the reinforcing bar diameter is known, and if the reinforcing bar diameter is known, the covering depth is diagnosed. Can be measured.
- the acoustic waveform is extremely large compared to a conventional device that measures the sound wave from an ultrasonic source by reflecting it off the rebar, and is extremely reliable compared to the conventional percussion method. It is non-destructive and can reliably diagnose and measure the degree of corrosion, adhesion, fogging depth, and diameter of rebar.
- the acoustic diagnostic / measurement device using pulsed electromagnetic force comprises a coil attached to a surface of a structure including a conductor and a non-conductor covering the conductor, and supplying a current pulse to the coil.
- Power supply unit a plurality of acoustic transducers to be installed at different positions on the surface of the structure, and a measuring unit that measures the sound propagation delay time from the output of the acoustic transducer.
- the feature is to measure.
- the acoustic diagnostic / measurement device using pulsed electromagnetic force of the present invention includes a coil attached to a surface of a structure made of a conductor and a non-conductive material covering the conductor, and applying a current pulse to the coil. It has a power supply unit to supply and a displacement detector that measures the vibration of the surface of the structure as optical displacement, and diagnoses and measures the position of the conductor and the corrosion and adhesion of the conductor. .
- the rebar since the rebar is directly excited by the magnetic field pulse, sound is generated with the rebar position as a sound source, and the sound propagates to the surface of the structure. If a laser interferometer is used as the displacement detector, it is possible to measure the minute vibration distribution and vibration propagation pattern on the entire surface, and to obtain more sophisticated information without destruction.
- the acoustic transducer according to claims 1 to 3 is preferably an acoustic emission sensor, an acceleration sensor, or an acoustic emission sensor that converts an acoustic signal into an electric signal. May be a microphone.
- the displacement detector according to claim 3 irradiates a coherent laser beam to the surface of the structure, and detects a phase difference caused by the vibration of the reflected light on the surface of the structure as an interference fringe. It may be a laser-interferometer.
- the coils described in claims 1 to 3 are composed of a single coil or a plurality of coils, and a combination of a plurality of coils is formed by aligning and closely contacting the axes of the plurality of coils.
- the power supply unit described in claims 1 to 3 includes a power storage capacitor connected in series to each of the plurality of coils, and a plurality of series circuits including the coil and the capacitor via a common switch. It consists of a power supply connected in parallel, and turns on a common switch to apply a current pulse to the coil to generate a magnetic field pulse.
- the inductance of each coil can be reduced, and the capacitance of each storage capacitor can be reduced.
- the time constant of the current pulse flowing through each individual coil can be reduced. Since the magnetic field pulses generated by the individual coils are superimposed, a magnetic field pulse having a high peak value and a narrow pulse width can be generated. Since a magnetic field pulse with a high peak value and a narrow pulse width can be generated, the rebar can be strongly excited, and non-destructive diagnosis and measurement can be performed reliably.
- the measuring section for measuring the output waveform described in claim 1 measures and displays a time domain waveform of the output waveform, and extracts features related to corrosion and adhesion from the time domain waveform.
- diagnosis and measurement relating to corrosion and adhesion can be instantaneously performed from a waveform in the time domain or a waveform in the frequency domain.
- the feature of extracting and displaying from the time domain waveform is the pattern of the time domain waveform.
- the waveform, crest factor, or crest factor is displayed.
- Information related to corrosion and adhesion is displayed by comparing the corrugation factor or crest factor with a predetermined threshold value, and displays information about good and bad corrosion and adhesion. It is characterized by doing.
- the waveform ratio and crest factor change easily depending on corrosion and adhesion, making it easy to diagnose. Also, the thresholds of the waveform rate and crest factor are set, and good / bad information is displayed depending on whether the measured waveform rate or crest factor is below the threshold value.
- the feature extracted and displayed from the waveform in the time domain is the severity extracted from the shape of the envelope of the waveform in the time domain.
- the feature is to display the information of good and bad about corrosion and adhesion. .
- the feature extracted and displayed from the time-domain waveform is a normalized waveform obtained by dividing each value of the time-domain waveform by an effective value, or a waveform obtained by raising the normalized waveform to a power.
- the characteristics of the normalized waveform in which each value of the time domain waveform is divided by the effective value, become clear. Exponentiation further clarifies and enables highly sensitive diagnosis and measurement. It is also characterized in that the severity is extracted from the envelope shape of the normalized waveform, the severity is compared with a predetermined threshold value, and information on good and bad corrosion and adhesion is displayed. Since the severity is determined from the normalized waveform, anyone can reliably diagnose and measure with even higher sensitivity.
- the feature extracted from the waveform in the frequency domain and displayed is the waveform pattern in the frequency domain.Information on corrosion and adhesion is displayed by comparing the waveform pattern with a predetermined pattern and examining the corrosion and adhesion. It is characterized by displaying good and bad information. Rebar vibration caused by pulsed electromagnetic force changes the degree of freedom of vibration depending on the corrosion and adhesion of the reinforcement, so the degree of corrosion and adhesion is very sensitively reflected in the frequency spectrum. You. Since good and bad information is displayed in comparison with the predetermined frequency pattern, anyone can surely diagnose and measure without the need for experience.
- the feature extracted and displayed from the frequency domain waveform is a normalized waveform formed by dividing each value of the frequency domain waveform by the effective value, or a waveform obtained by raising the normalized waveform to a power.
- To display information on adhesion extract the severity from the envelope of the normalized waveform, compare the severity with a predetermined threshold, and display good or bad information on corrosion and adhesion. It is characterized by.
- the waveform in the frequency domain reflects the degree of corrosion and adhesion very sensitively, and the normalized waveform formed by dividing each value of the waveform in the frequency domain by the effective value further emphasizes the characteristics of the waveform. Corrosion with high sensitivity 'Diagnosis of adhesion' can be evaluated. If the severity is obtained from the normalized waveform, diagnosis and evaluation can be performed with high sensitivity and high reliability. Also, by setting the severity L and the value, and displaying the good or bad information depending on whether the measured severity is below or above the threshold, anyone can reliably diagnose and measure without the need for experience etc. . Further, the displacement detector according to claim 3 irradiates a coherent laser beam to the surface of the structure, and detects a phase difference caused by the vibration of the reflected light on the surface of the structure as an interference fringe. It is a laser-interferometer.
- the measuring method comprises mounting a coil on a surface of a structure including a conductor and a non-conductor covering the conductor.
- a current pulse is applied to the coil to generate a magnetic field pulse, the magnetic field pulse induces an eddy current in the conductor, and the interaction between the eddy current and the magnetic field pulse excites the conductor to generate sound.
- the acoustic signal is converted to an electrical signal by an acoustic transducer attached to the surface of the structure or a conductor exposed from the non-conductor, and the waveform of the electrical signal is measured to diagnose corrosion or adhesion of the conductor. It is characterized by measuring.
- the reinforcement is directly excited by a magnetic field pulse, so that sound is generated from the position of the reinforcement, and this sound is generated on the surface of the structure.
- the acoustic waveform propagating on the surface of the structure changes according to the degree of corrosion and the adhesion of the reinforcing bar, and the degree of corrosion and the strength of the adhesion can be diagnosed and measured from the analysis of the acoustic waveform.
- the measurement method is as follows: a coil is attached to the surface of a structure consisting of a conductor and a non-conductor covering the conductor, and a current pulse is applied to the coil.
- a magnetic field pulse is generated by applying the magnetic field pulse, an eddy current is induced in the conductor by the magnetic field pulse, and the conductor is excited by an interaction force between the eddy current and the magnetic field pulse to generate sound, and the acoustic signal is transmitted to the structure.
- a plurality of acoustic transducers attached to different locations on the surface of the device convert it into electrical signals, measure the sound propagation delay time from these electrical signals, and measure the position of the conductor from these propagation delay times.
- the reinforcing bar is directly excited by the magnetic field pulse, sound is generated with the position of the reinforcing bar as a sound source, and the sound propagates to the surface of the structure. Since the propagation delay time of this sound is measured at multiple locations on the surface, the position of the rebar can be accurately determined without destruction.
- the coil is mounted on a surface of a structure including a conductor and a non-conductor covering the conductor.
- a current pulse is applied to the coil to generate a magnetic field pulse, the magnetic field pulse induces an eddy current in the conductor, and the interaction between the eddy current and the magnetic field pulse excites the conductor to generate sound.
- the present invention is characterized in that the surface vibration of a structure caused by sound is detected as an optical displacement, and the position of a conductor and the state of the structure are diagnosed.
- the reinforcing bar is directly excited by the magnetic field pulse, sound is generated with the position of the reinforcing bar as a sound source, and the sound propagates to the surface of the structure.
- a laser-interferometer is used for the displacement detector, it is possible to measure the minute vibration distribution and the vibration propagation mode on the entire surface, and it is possible to perform advanced diagnosis nondestructively and reliably.
- an acoustic diagnosis using a pulsed electromagnetic force is a method for measuring a sound by attaching a coil to a surface of a non-conductor covering the conductor and applying a current pulse to the coil.
- a magnetic field pulse is generated, an eddy current is induced in the conductor by the magnetic field pulse, and the conductor is excited by an interaction force between the eddy current and the magnetic field pulse to generate sound.
- the acoustic signal is converted into an electric signal by an acoustic transducer attached to the surface of the structure, and the waveform of the electric signal is measured to measure the diameter of the conductor or the fogging depth.
- the amplitude of the acoustic waveform changes according to the rebar diameter and the cover depth, so if the rebar depth is known, the rebar diameter is known, and if the rebar diameter is known, the cover depth is known. Saga can be diagnosed and measured.
- the measurement method comprises disposing a coil directly above a joint portion of a plurality of conductors joined to each other via a fastener. Then, a current pulse is applied to the coil to generate a magnetic field pulse, the magnetic field pulse induces an eddy current in the conductor facing the coil, and the conductor is excited by the interaction force between the eddy current and the magnetic field pulse.
- the sound signal is converted into an electric signal by an acoustic transducer attached to the conductor facing the coil and an acoustic transducer attached to another conductor connected to the coil.
- Diagnose and measure the tightening of the fastener by comparing the waveform of the electrical signal from the acoustic transducer attached to the conductor facing the side with the waveform of the electrical signal from the acoustic transducer attached to the other conductor. It is characterized by the following.
- the strength of the vibration of the conductor facing the coil transmitted to other conductors changes according to the degree of tightening, so that the degree of tightening can be diagnosed and measured.
- the fastener is a bolt and a nut, it can be suitably applied.
- the measuring method comprises: arranging a coil on a surface of a non-conductor covering a conductor, and applying a current pulse to the coil.
- a magnetic field pulse is generated, an eddy current is induced in a conductor by the magnetic field pulse, and a conductor is excited by an interaction force between the eddy current and the magnetic field pulse to generate sound, and the conductor is exposed from the non-conductor.
- the conductor is most strongly excited when the conductor is closest to the coil, so that the position of the conductor can be diagnosed and measured.
- the present invention can be suitably applied to a water pipe or a gas pipe in which the conductor is buried in the soil.
- the measurement method comprises disposing a coil on a surface of a structure including a conductor and a non-conductor covering the conductor. A current pulse is applied to the coil to generate a magnetic field pulse, an eddy current is induced in the conductor by the magnetic field pulse, and the interaction between the eddy current and the magnetic field pulse excites the conductor to generate sound.
- the sound signal is converted to an electric signal by an acoustic transducer attached to the conductor exposed from the non-conductor, and the presence or absence of a rupture of the conductor is diagnosed based on the strength of the electric signal.
- the method is characterized in that the position of the coil is changed, the change in the electric signal due to the change in the position is measured, and the position of the rupture of the conductor is measured. According to this method, since the acoustic signal propagating through the reinforcing bar is attenuated by the fracture, the presence or absence of the fracture can be determined.In addition, the fracture is determined from the change in the attenuation by measuring the position of the coil on the surface of the structure. The position of is known.
- the structure can be suitably applied to a prestressed concrete structure, that is, a bridge, a concrete utility pole or a concrete sleeper using this method.
- a reinforced concrete structure such as a tunnel, a bridge, a building, a retaining wall, a dam, a civil engineering building, etc.
- not only the position of the internal reinforcing bar but also the adhesive force of the reinforcing bar, Corrosion of reinforcing bars, separation of concrete, cracks, etc. can be detected, so that it is possible to prevent damage to reinforced concrete structures and separation of concrete pieces. Since it is also possible to accurately estimate the remaining life of reinforced concrete structures, the maintenance and management of reinforced concrete structures can be performed reliably.
- cover depth and diameter of the reinforcing bar can be measured.
- FIG. 1 is a conceptual diagram showing an embodiment of a sound diagnosis / measurement device and a diagnosis / measurement method using a pulsed electromagnetic force according to the present invention described in claim 1, and FIG. Fig. 1 (b) shows the measurement when the transducer is mounted on a concrete surface and the acoustic transducer is mounted on an exposed reinforcing bar.
- FIG. 2 is a diagram showing the shape of a test reinforced concrete used in Example 1 and a measurement system, wherein (a) is a plan view and (b) is a side view.
- Fig. 3 shows the acoustic waveforms of the normal test block and the crack test block.
- A shows the acoustic waveform of the normal block
- (b) shows the acoustic waveform of the crack block.
- FIG. 4 is a diagram showing a configuration of an acoustic diagnosis / measurement device using pulsed electromagnetic force of the present invention described in claim 2.
- FIG. 5 is a diagram showing the surface shape of the reinforced concrete used in the present example and a method for producing the reinforced concrete.
- (A) is a diagram showing the surface shape of reinforced concrete
- (b) is an outer frame for producing reinforced concrete
- (c) is a diagram showing the appearance of reinforced concrete.
- FIG. 6 is a diagram showing a measurement result of a sound propagation delay time due to a difference in a distance from a sound source in a reinforced concrete.
- Fig. 7 shows the sound speed in concrete measured from various distances from the sound source and the propagation delay time.
- FIG. 8 is a diagram showing a configuration of a coil and a power supply unit, where (a) shows a conventional configuration example and (b) shows a configuration of the present invention.
- FIG. 9 is a diagram showing a current pulse waveform by the coil and the power supply unit of the present invention, and an example of measurement of an acoustic signal generated by the current pulse waveform.
- FIG. 9 (a) shows a conventional configuration, and FIG. Is shown.
- Fig. 10 shows the waveforms output from the acoustic transducers of test blocks (A), (B), and (C) as time-domain waveforms by the main measurement unit, and (a), (b), (c) FIG.
- FIG. 11 shows the output waveforms of the test blocks (A), (B), and (C) measured by attaching the acoustic transducer directly to the reinforcing bar, and the main measurement unit uses the output waveforms in the time domain as (a) , (B) and (c).
- FIG. 12 is a diagram comparing the waveform ratio SF and the crest factor CF of the test blocks (A), (B), and (C).
- FIG. 13 is a diagram showing the respective envelopes (a) and reciprocal logarithmic envelopes (b) of the test blocks (A), (B) and (C).
- FIG. 14 is a diagram showing the time domain waveform (a), the normalized waveform (b), and the squared waveform of the normalized waveform (c) of the test block (A).
- FIG. 15 is a diagram showing a cubic waveform (a) of the normalized waveform and a quartic waveform (b) of the normalized waveform of the test block (A).
- FIG. 16 is a diagram showing the time domain waveform (a), the normalized waveform (b), and the squared waveform of the normalized waveform (c) of the test block (B).
- FIG. 17 is a diagram showing a cubed waveform (a) of the normalized waveform of the test block (B) and a quartic waveform (b) of the normalized waveform.
- FIG. 18 is a diagram showing a time-domain waveform (a), a normalized waveform (b), and a squared waveform (c) of the normalized waveform of the test block (C).
- FIG. 19 is a diagram showing a cubic waveform (a) of the normalized waveform of the test block (C) and a quartic waveform (b) of the normalized waveform.
- FIG. 20 is a diagram showing waveforms in the frequency domain obtained from the waveforms in the time domain of test blocks (A), (B), and (C) obtained in the third embodiment, where (a) shows the test block. (A), (b) shows the frequency domain waveform of the tested block (B), and (c) shows the frequency domain waveform of the test block (C).
- FIG. 21 is a diagram showing waveforms in the frequency domain obtained from the time domain waveforms of the test blocks (A), (B), and (C) obtained in the fourth embodiment, where (a) is a test block.
- FIGS. 22A and 22B are diagrams showing a method for measuring the reinforcing bar diameter or the fogging depth of the present invention, and a measurement example, wherein FIG. 22A is a diagram showing a measurement method, and FIG. 22B is a diagram showing a measurement result.
- FIG. 23 is a diagram showing a method of diagnosing and measuring the tightening of the fastener according to the present invention.
- FIG. 23 (a) shows a method in which the conductor 21 and the conductor 22 are connected to each other with a bolt 22 and a nut 23.
- FIG. 2 is a side view of the state where the cable is fastened and fixed through the, and
- FIG. Fig. 24 shows the measurement results when the bolts and nuts were firmly tightened.
- FIG. 25 is a diagram showing the measurement results when the bolts and nuts are loosened, and (a) and (b) show the acoustic transducer 1 attached to the conductor 21 on the side facing the coil. 4C shows the output waveform, and (c) and (d) show the output waveforms of the acoustic transducer 14L on the conductor 22 side fixed to the conductor 21 with bolts and nuts.
- FIG. 26 is a view showing a method for measuring the position of a conductor embedded in a non-conductor according to the present invention, wherein (a) shows a conductor embedded in a non-conductive soil 31.
- the acoustic transducer 14 is attached to the exposed part 3 3 of the water pipe 3 2, and the coil 12 is placed on the surface 34 of the soil 31 from a side view.
- FIG. FIG. Fig. 27 is a diagram showing the results of measuring the position of a water pipe embedded in the soil, (a) when the coil is directly above the water pipe, and (b) when the coil is on the surface of the soil.
- (C) shows the waveform of the acoustic signal at a distance of 180 mm from the position directly above the water pipe on the soil surface when it was 60 mm away from the position directly above the water pipe.
- FIG. 28 is a diagram showing a method for diagnosing the presence or absence of a break in a conductor embedded in a non-conductor and measuring the position of the break according to the present invention.
- a structure composed of a conductor and a non-conductor covering the conductor is a reinforced concrete composed of a reinforcing bar and a concrete.
- This device can diagnose or measure corrosion, adhesion, cover depth, and diameter of rebar.
- FIG. 1 is a conceptual diagram showing an embodiment of a sound diagnosis / measurement device and a diagnosis / measurement method using pulsed electromagnetic force according to the present invention described in claim 1;
- FIG. Fig. 1 (b) shows the measurement when the acoustic transducer is mounted on the exposed reinforcing steel while the acoustic transducer is mounted on the concrete surface.
- the acoustic diagnostic / measuring device 10 using pulsed electromagnetic force is composed of a coil 12 composed of electric wires attached to the surface of a reinforced concrete block 11, which is a test object structure, and a coil 1 Power supply unit 13 for applying a current pulse to 2; acoustic transducer 14 attached to the surface of reinforced concrete block 11; measuring unit 15 connected to acoustic transducer 14 by signal cable 17 Is composed of ⁇
- the coil 12 is constituted by, for example, four coils obtained by winding a 1.6 mm conducting wire around a 50 ⁇ 30 mm rectangular frame for 7 turns, with their axes aligned and in close contact with each other.
- the coil 12 is attached to the surface of the reinforced concrete block 11 which is the specimen.
- the power supply section 13 applies a current pulse to the coil 12 via the power cable 16.
- the power supply section 13 is not limited to the above configuration, and can generate a desired drive pulse in accordance with the size of the reinforced concrete block 11, the position and the thickness of the reinforcing bar 11a, and the like. It is configured to be able to.
- the acoustic transducer 14 is a well-known acoustic transducer, detects a weak vibration, converts it into an electric signal, and inputs the electric signal to the measuring unit 15 via the signal cable 17.
- the measuring unit 15 has a known configuration, for example, which is commercially available as an acoustic analyzer, and amplifies a detection signal from the acoustic converter 14 by an amplifier or the like, and removes unnecessary signals by a filter or the like. After that, acoustic analysis is performed. Note that the measuring unit 15 is not limited to this, and if it is sufficient to measure only the waveform of the detection signal from the acoustic converter 14, an oscilloscope, for example, may be used.
- the acoustic diagnostic apparatus 10 using pulsed electromagnetic force of the present invention is configured as described above. When a current pulse is applied to the coil 12, a magnetic field pulse is generated in the direction of the inside of the reinforced concrete 11.
- the reinforcing bar 11a which is a conductor.
- the rebar 11a is excited by the interaction force between the magnetic field caused by the eddy current and the magnetic field of the magnetic field pulse.
- the conductor 11a is a magnetic material, the force accompanying the magnetic energy is also added to the excitation force and strengthened.
- the measurement unit 15 analyzes the waveform of the electric signal to determine the degree of corrosion of the reinforcing bar 11a or the crack of the concrete 11b. For example, if the reinforcing bar 11a is corroded, the sound from the reinforcing bar 11a as a sound source is absorbed and attenuated by the corroded portion, and the waveform observed by the measuring unit 15 has a small intensity.
- the waveform observed by the measuring unit 15 similarly has a low intensity. Also, if cracks are present in the concrete, the sound will be attenuated, and the waveform observed by the measuring unit 15 will have low intensity. Thus, the degree of damage to the reinforced concrete 11 can be measured by comparing the intensity of the acoustic waveform.
- the acoustic transducer 14 can be attached to the exposed part of the reinforcing bar to directly observe the vibration of the reinforcing bar, and diagnose and measure the corrosion and adhesion of the reinforcing bar. .
- Example 1 will be described.
- Example 1 shows an example of measurement by an acoustic diagnosis / measurement device using pulsed electromagnetic force according to the present invention described in claim 1.
- FIG. 2 is a diagram showing the shape of a test reinforced concrete used in Example 1 and a measurement system, wherein (a) is a plan view and (b) is a side view.
- the test reinforced concrete 11 is composed of a square 200 x 150 x 100 mm concrete 11b and a distance from the upper surface of the concrete 11b, i.e., covering. It consists of a 13 mm diameter reinforcing bar 11a buried at a depth d of 3 O mm and a distance of 57 mm from the lower surface.
- the coil 12 is disposed on the surface of the reinforced concrete 11 directly above the reinforcing bar 11a.
- the acoustic transducers 14a and 14b are arranged symmetrically with respect to the reinforcing bar 11a on the surface of the reinforced concrete 11 ⁇
- a test reinforced concrete (normal test block) having no cracks in the concrete 11b and a test reinforced concrete (crack reaching the reinforcing bar 11a in the concrete 11b) were used.
- a crack test block was produced, and excitation was performed under the same conditions, and the sound waveforms observed by the sound transducers 14a and 14b were compared.
- the coil 12 has a winding diameter of 30 x 70 mm and a resistance of 0.2 ⁇ with a winding diameter of 25 turns of a 1.0 mm wire, and has a current peak value of 100 A and a pulse width of 1.
- a 5ms current pulse was applied to excite the reinforcing bar 11a.
- Fig. 3 shows the sound waveforms of the normal test block and the crack test block.
- Fig. 3 (a) shows the sound waveform of the normal block
- Fig. 3 (b) shows the sound waveform of the crack block.
- CH I and CH 2 are output waveforms of the acoustic transducers 14a and 14b, respectively
- CH 3 is a current pulse waveform.
- the horizontal axis is the time axis displayed at 0.5 ms / diV
- the vertical axis is the voltage axis showing the intensity of the acoustic waveform of CH 1 and CH 2.
- CH 1 and CH 2 are displayed with the zero point shifted. are doing.
- the presence or absence of cracks in the concrete can be diagnosed.
- an embodiment of the acoustic diagnosis / measurement device using pulse electromagnetic force and the acoustic diagnosis / measurement method using pulse electromagnetic force according to the present invention described in claim 2 will be described. According to this device, the position of the reinforcing bar in the reinforcing bar concrete can be measured.
- FIG. 4 is a conceptual diagram showing a configuration and a measuring method of an acoustic diagnostic / measuring device using pulsed electromagnetic force according to the present invention described in claim 2.
- the acoustic position locating device 20 is composed of a coil 12 composed of electric wires attached to the surface of the reinforced concrete block 11, and a power supply unit 13 for applying a current pulse to the coil 12.
- a power supply unit 13 for applying a current pulse to the coil 12.
- multiple acoustic transducers 14 (14a, 14b, 14c) attached to the surface of the reinforced concrete 11 and the acoustic transducer ⁇ consists of a measuring section 15 (not shown because it is equivalent to Fig. 1) and a measurement section 15 connected by a signal cable 17 (not shown because it is equivalent to Fig. 1).
- a plurality of acoustic transducers 14 are arranged around the coil 12, and a current pulse is applied to the coil 12 to excite the reinforcing bar 11 a to generate sound using the reinforcing bar 11 a as a sound source.
- This sound is converted into an electric signal by each sound transducer 14, and the electric signal reaches each sound transducer 14 from the sound source by measuring each electric signal by the measuring unit 15. The time, that is, the propagation delay time is measured.
- the distance between each acoustic transducer 14 and the sound source is calculated using the propagation velocity V and the delay time t]:
- the distance between the converter 14 and the reinforcing bar 11a can be obtained. From these distances, the position of the sound source, that is, the location of the reinforcing bar 11a can be determined. For example, as shown in FIG. 4, if the reinforcing bar 11a is rod-shaped, based on the delay times ta, tb, and tc of the acoustic transducers 14a, 14b, and 14c, respectively.
- a plurality of acoustic transducers 14 are arranged on the surface of concrete 11 to generate a single acoustic signal, and the propagation delay time at each acoustic transducer 14 is measured simultaneously.
- a configuration may be used in which one acoustic transducer 14 is moved on the surface of the concrete 11 and an acoustic signal is generated at each moving position to individually measure the propagation delay time.
- Example 2 shows an example of measurement by an acoustic diagnosis / measurement device using pulsed electromagnetic force according to the present invention described in claim 2.
- FIG. 5 is a diagram showing the surface shape of the reinforced concrete used in the present example and a method for producing the reinforced concrete.
- (A) is a diagram showing the surface shape of reinforced concrete
- (b) is an outer frame for making reinforced concrete
- (c) is a view showing the appearance of the reinforced concrete.
- the reinforced concrete used in this example was prepared by pouring the concrete into an outer frame, which is often made of elastic vinyl sheets except for the center of the reinforcing bar 11a. Therefore, in this reinforced concrete, only the center of the reinforcing bar 11a is in contact with the concrete 11b, and the other part of the reinforcing bar 11a is not in contact with the concrete 11b. For this reason, the excited sound is transmitted to the concrete only from the central part of the reinforcing bar 11a, and the sound source can be regarded as a point sound source.
- the center of reinforced concrete 11 The longitudinal direction was set to the x-axis and y-axis, respectively.
- the coil was placed at the origin, and the acoustic transducer was placed at various coordinates (X, y), and the sound propagation delay time was measured.
- the excitation coil, acoustic transducer, and current pulse are the same as in the first embodiment.
- FIG. 6 is a diagram showing a measurement result of a sound propagation delay time due to a difference in a distance from a sound source in a reinforced concrete.
- CH 1 and CH denote the acoustic waveforms when the acoustic transducer is placed at the coordinates ( ⁇ 1, 0) and (3, 2) shown in FIG. This is the waveform of the current pulse.
- the horizontal axis is the time axis represented by 0.1 lmsZdiv, the vertical axis is the voltage axis indicating the intensity of the acoustic waveform of CH1 and CH2, and CH1 and CH2 are displayed with the zero point shifted.
- the distance from the sound source can be detected as the propagation delay time.
- Fig. 7 shows the sound speed in concrete measured from various distances from the sound source and the propagation delay time.
- the distance from the sound source indicates the distance between each coordinate point in FIG. 6 (a) and the sound source.
- the measurement of the propagation delay time is equivalent to the method described in FIG.
- the distance to the sound source can be determined from the propagation delay time described in FIG. 6 and the sound velocity described in FIG. If the number of measurement points is increased and the distance from each measurement point to the sound source is found, and the position in reinforced concrete that satisfies all of these distances is found, the location of the reinforcing bar is obtained.
- the acoustic diagnosis / measurement device of the present invention has a surface displacement detector installed in place of the acoustic transducer 14 and reads the vibration of the surface of the test object structure 11 instead of the sound.
- the configuration is the same as that of the acoustic diagnostic apparatus 10.
- any type of detector can be used as long as it can measure a minute displacement, but in particular, a coherent laser beam is applied to the structure 11 If a laser-interferometer that irradiates the entire surface and detects the phase difference of the reflected light accompanying the vibration of the surface of the test object structure 11 as interference fringes is used, more precise and advanced diagnosis can be performed.
- FIG. 8 is a diagram showing a configuration of a coil and a power supply unit.
- FIG. 8 (a) shows an example of a conventional configuration
- FIG. 8 (b) shows a configuration of the present invention.
- the conventional configuration as shown in Fig. 2 (a), consists of a single coil, charges the capacitor C with the AC voltage V from the commercial power supply AC, and transfers the charge of the charged capacitor C to the power source.
- a switch SW which is a CAL switch or a semiconductor switch is turned on, a current pulse is applied to the coil 12.
- the coil and the power supply of the present invention are divided into a plurality of coils 12 having a small inductance, and each coil is a magnetic field generated by each coil. The coils are aligned and closely contacted so that they are superimposed.
- Capacitors C are connected in series to each coil, and four series circuits consisting of coils 12 and C are connected to a common power supply V. Furthermore, they are connected in parallel via a common switch SW, which is a mechanical switch or a semiconductor switch.
- the inductance of each series circuit is small, and the capacitance of each capacitance c is also small, so that the time constant of the current pulse when SW is set to 0 N can be reduced. Since the generated magnetic field pulse is superimposed, a magnetic field pulse having a short pulse width and a large peak value can be obtained.
- FIG. 9 is a diagram showing a current pulse waveform by the coil and the power supply unit of the present invention and an example of measurement of an acoustic signal generated thereby.
- FIG. 9 (a) shows a conventional configuration of the ninth embodiment.
- FIG. 2B shows the configuration according to the present invention.
- the measurement of the acoustic signal was carried out by the acoustic diagnostic apparatus using pulse electromagnetic force of the present invention. Reinforced concrete with a cover depth d of 3 O mm. Reinforcing bar 13 D (deformed bar 13 mm) used.
- the current pulse width is much smaller and the power is larger according to the configuration of the coil and the power supply unit of the present invention as compared with the conventional configuration.
- the received waveform of the AE (acoustic emission) sensor that is, the output waveform of the acoustic converter
- the received waveform of the AE (acoustic emission) sensor is far greater according to the configuration of the coil and the power supply unit of the present invention than in the conventional configuration. It turns out that it becomes large.
- a magnetic field pulse having a narrow pulse width and a large peak value can be generated, and as a result, the reinforcing bar can be strongly excited.
- the measurement unit of the present invention samples the output waveform of the acoustic converter, A / D converts the sampled value, stores the AZD-converted digital data in a memory, and converts the digital data into a predetermined data via the CPU.
- a predetermined operation is performed according to a program having a signal processing procedure, and the result is stored in a memory or displayed via a display device.
- a predetermined signal processing procedure program is a program for displaying a time domain waveform of an output waveform, and calculating and displaying a frequency domain waveform composed of a Fourier transform spectrum of the output waveform based on the time domain waveform of the output waveform.
- AZD converter As the above sampling device, AZD converter, memory, CPU, and display device, commercially available general-purpose devices can be used. With this configuration, it is possible to measure and display the waveform in the time domain, and to display information on corrosion and adhesion. In addition, features related to corrosion and adhesion are extracted and displayed from the waveform in the time domain, or the waveform in the frequency domain consisting of the Fourier transform spectrum of the output waveform is calculated and displayed, and the waveform in the frequency domain is displayed. Features related to corrosion and adhesion can be extracted and displayed, and information about corrosion and adhesion can be displayed. Next, a third embodiment will be described.
- Example 3 shows that the feature relating to corrosion and adhesion can be extracted from the waveform in the time domain.
- test blocks were 13D (deformed bar 13 m0) and had a cover depth d of 30 mm. 200 mm X 150 mm.
- a coil 12 and an acoustic transducer 14 were mounted on the surface of the above test block, and a current pulse having a peak current value of 200 A and a pulse width of 350 ⁇ s was applied to the coil 12 to excite the reinforcing bar. .
- Fig. 10 (a), (b) and (c) show the output waveforms of the sound transducers of each test block (A), (B) and (C) as time domain waveforms by the main measurement unit FIG.
- normal reinforced concrete (A) shows a waveform close to a triangular shape with a symmetry axis and a vertex in the time axis direction.
- the cracked test block (B) has a waveform similar to a square shape with a symmetry axis and a vertex in the time axis direction.
- the test block (C) which has no adhesion between the reinforcing steel and concrete, shows almost no output waveform.
- Example 4 as shown in Fig. 1 (b), even when an acoustic transducer (AE sensor) was attached to a reinforcing bar exposed from reinforced concrete, the waveform in the time domain could be used to determine the corrosion and adhesion. This indicates that features can be extracted.
- AE sensor acoustic transducer
- FIG. 11 (a), (b) and (c) show the actual measurement of the output waveform measured by attaching an acoustic transducer directly to the reinforcing bar of each test block (A), (B) and (C).
- FIG. 5 is a diagram displayed as a waveform in a time domain by a unit.
- the cracked test block (B) shows a waveform close to a triangular shape with a symmetry axis and a vertex in the time axis direction.
- the test block (C) which has no adhesive force between the reinforcing bar and the concrete, shows a waveform close to a triangular shape having a symmetric axis and a vertex in the time axis direction, but shows a long tail in the time axis direction. This is because there is no adhesive force between the reinforcing bar and the concrete, that is, since there is a gap between the reinforcing bar and the concrete, the damping force of the reinforcing bar is small and the vibration continues for a long time.
- the waveform in the time domain is displayed by the measurement unit of the apparatus of the present invention, even if the acoustic transducer is directly attached to the reinforcing bar, the difference in the adhesive force of the reinforcing bar appears in the waveform shape.
- X be the data value of each time-domain waveform, and let N be the total number of data.
- the average value X is defined by the following equation.
- the effective value X is defined by the following equation,
- the peak value X p is defined by the following equation,
- the waveform ratio SF is defined by the following equation.
- the waveform factor SF and the crest factor are calculated. CF is obtained and compared.
- FIG. 12 is a diagram comparing the test patterns (A), (B), and (C) with respect to the waveform factor SF and the crest factor CF.
- the waveform factor SF and the crest factor CF are clearly different depending on the test block, that is, depending on the adhesion of the reinforcing bar.
- the measuring section calculates the waveform ratio SF and the crest factor CF to be measured by the predetermined signal processing procedure program, and for example, sets the threshold of the waveform ratio in FIG. , Or set the crest factor threshold to 5.50, determine whether the waveform rate or crest factor of the measured object is less than or greater than these thresholds, and pass or fail information indicate.
- the measurement unit extracts features related to corrosion and adhesion due to the severity extracted from the shape of the envelope of the waveform in the time domain, and displays information.
- the probability P (y ; ) is defined by the following equation.
- an envelope is obtained from the time domain waveforms of the test blocks (A), (B), and (C) obtained in the third embodiment, and the severity is compared.
- FIG. 13 is a diagram showing test envelopes (A), (B) and (C) of respective envelopes (a) and reciprocal logarithmic envelopes (b).
- the reciprocal logarithmic envelope is an envelope obtained by taking the logarithm of the reciprocal of the probability P (Y i).
- the envelopes of test blocks (B) and (C) deviate considerably from the envelope of test block (A).
- the envelopes of the test blocks (B) and (C) are the envelopes after a certain period of use, the envelopes can be compared.
- the reciprocal logarithmic envelope also shows a clear difference from the initial state, and this difference is added up on the time axis. Diagnose.
- the measuring unit calculates the envelope, the reciprocal logarithmic envelope, and the severity of the object to be measured by the predetermined signal processing procedure program, and compares the calculated envelope with the predetermined threshold of the severity. Judge whether the value is below or above the threshold, and display information on good or bad.
- each value of the time domain waveform by this measurement unit is calculated as the effective value of the time domain waveform Extraction of characteristics related to corrosion / adhesion and display of information based on the normalized waveform divided by or the power of the normalized waveform will be explained.
- the normalized waveform is a waveform obtained by dividing the data value X i of the time-domain waveform by the effective value x rm shown in equation (2).
- the normalized waveforms of the test blocks (A), (B), and (C) are obtained from the time domain waveforms of the test blocks (A), (B), and (C) measured in the third embodiment.
- the power waveform of the standardized waveform is calculated and compared.
- FIG. 14 is a diagram showing a time domain waveform (a), a normalized waveform (b), and a squared waveform of the normalized waveform (c) of the test block (A).
- FIG. 15 is a diagram showing a cubic waveform (a) of the normalized waveform of the test block (A) and a quartic waveform (b) of the normalized waveform.
- FIG. 16 is a diagram showing a time domain waveform (a), a normalized waveform (b), and a squared waveform of the normalized waveform (c) of the test block (B).
- FIG. 17 is a diagram showing a cubic waveform (a) of the normalized waveform and a quartic waveform (b) of the normalized waveform of the test block (B).
- FIG. 18 is a diagram showing a time domain waveform (a), a normalized waveform (b), and a squared waveform (c) of the normalized waveform of the test block (C).
- FIG. 19 is a diagram showing a cubic waveform (a) of the normalized waveform and a quartic waveform (b) of the normalized waveform of the test block (C).
- the normalized waveform and the power waveform of the normalized waveform differ from the time domain waveform by the test blocks (A), (), and (C). 'It can be seen that there is a large difference depending on the degree of adhesive force, and that the difference is particularly large for higher-order power-law waveforms.
- the degree of corrosion and adhesion can be diagnosed with high sensitivity.
- the measurement unit calculates the normalized waveform and the power waveform of the normalized waveform from the time domain waveform by the predetermined signal processing procedure program, extracts the characteristic, and compares the characteristic with the threshold. To determine whether it is below or above the threshold and display good or bad information. Show.
- the waveform in the frequency domain is obtained by performing a Fourier transform on the waveform in the time domain by the signal processing procedure program of this measurement unit.
- the time-domain waveforms of the test blocks (A), (B), and (C) obtained in the third and fourth embodiments are Fourier-transformed to obtain a frequency-domain waveform.
- FIG. 20 is a diagram showing waveforms in the frequency domain obtained from the waveforms in the time domain of test blocks (A), (B), and (C) obtained in the third embodiment.
- test block (A) which is a normal reinforcing bar
- frequency components exist randomly and almost continuously in the frequency range from 20 kHz to 80 kHz.
- test block (B) which is a cracked reinforcing bar, specific frequency components appear at specific intervals.
- test block (C) which is a reinforcing bar that has lost its adhesive force, although not as noticeable as in the case of the test block (B), specific frequency components appear at specific intervals. In addition, the frequency component around 150 kHz increases.
- test block (A) test block (B)
- the difference in B) is extremely remarkable. Even when it is difficult to distinguish the difference from the time domain waveform, the difference can be clearly identified by using the frequency domain waveform.
- FIG. 21 shows the waveform in the frequency domain obtained from the time domain waveforms of the test blocks (A), (B), and (C) measured by attaching the acoustic transducer directly to the reinforcing bar, obtained in Example 4.
- (A) shows the test block (A)
- (b) shows the test block (B)
- (c) shows the test block (C) in the frequency domain.
- the measurement unit calculates the waveform in the frequency domain from the waveform in the time domain according to the predetermined signal processing procedure program, compares it with the reference pattern, calculates the degree of coincidence, and calculates the degree of coincidence. Compare with the threshold to determine whether it is below or above the threshold and display good or bad information.
- the measurement unit obtains a normalized waveform or a power waveform of the normalized waveform from the frequency domain waveform by the same means as described in the sixth and seventh embodiments, and obtains the normalized waveform or the normalized waveform.
- the power of the waveform it is possible to extract features related to corrosion and adhesion with extremely high sensitivity.
- the severity is calculated from the normalized waveform or the power waveform of the normalized waveform, and compared with a predetermined threshold of the severity, it is determined whether the severity of the object to be measured is below or below the threshold. Judgment can be made based on sensitivity, and information on good or bad can be displayed.
- FIG. 22 is a diagram showing a method for measuring the reinforcing bar diameter or the fogging depth, and a measurement example according to the present invention, wherein (a) is a diagram showing a measurement method, and (b) is a diagram showing a measurement result. .
- a coil 12 is installed directly above the reinforcing bar 11a of the reinforced concrete 11, an acoustic transducer 14 is mounted on the surface of the reinforced concrete 11, and a magnetic field pulse is applied from the coil 12. Then, the reinforcing bar 11a is excited, the acoustic signal using the reinforcing bar 11a as a sound source is converted into an electric signal by the acoustic converter 14, and the peak value of the peak value of the acoustic signal is measured by the measuring unit 15.
- ⁇ Measure characteristic values such as peak values.
- the reinforcing bar diameter corresponding to the measured characteristic value and cover depth is obtained using the correspondence relationship between the reinforcing bar diameter, the cover depth and the special value prepared in advance. If the cover depth d is unknown, measure the cover depth d by the method described in claim 2. If the rebar diameter is known and the cover depth d is not known, the characteristics measured using the measured feature values and the correspondence between the prepared bar diameter, cover depth and special values are used. ⁇ ⁇ ⁇ Calculate the cover depth d corresponding to the value and the reinforcing bar diameter.
- the vertical axis in (b) is the special value. In this example, the peak-to-peak value of the peak value was used.
- the horizontal axis is the cover depth d.
- rebars with different diameters 10 d, 13 d, 16 d, 19 d, 25 d deformed rebars 1 Omm0, 13 mm ⁇ , 16 mm ⁇ . The dependence of the feature value of 25 mm ⁇ ) on the fogging depth d was measured.
- the characteristic value depends on both the reinforcing bar diameter and the cover depth d. Therefore, the cover depth d or the reinforcing bar diameter can be measured based on the correspondence relationship prepared in advance.
- FIG. 23 is a diagram showing a method of diagnosing and measuring the tightening condition of the fastener according to the present invention.
- FIG. 23 (a) shows that the conductor 21 and the conductor 22 are connected to each other by a bolt 23 and a nut 2.
- FIG. 4 is a side view of a state in which it is fastened and fixed via 4, and FIG.
- the coil 12 is arranged just above the port 22 of the conductor 21, and the acoustic transducers 14 R and 14 L are attached to the surfaces of the conductor 21 and the conductor 22, respectively.
- Example 9 shows that the tightening condition of the fastener can be diagnosed and measured by the method of diagnosing and measuring the tightening condition of the fastener according to the present invention.
- the current pulse applied to the coil has a peak value of 200 OA -, The pulse width is 350 ⁇ s.
- Fig. 24 shows the measurement results when the port nut was tightly tightened.
- (A) and (b) show the acoustic transducer attached to the conductor 21 on the side facing the coil.
- 14C shows the output waveform of the acoustic transducer 14 L on the conductor 22 side fixed to the conductor 21 with bolts and nuts, and FIGS. (A) and (c) were measured by passing through a BP (bandpass filter: pass band 20 kHz to 500 kHz)) and cutting frequency components below 20 kHz.
- (B) and (d) are output waveforms of all frequency components up to 500 kHz.
- the output waveform of the acoustic transducer 14 R is equivalent to the output waveform of the acoustic transducer 14 R.
- FIG. 25 shows the measurement results when the port nut is in a loosened state.
- FIGS. 25 (a) and (b) show the acoustic transducer 1 attached to the conductor 21 on the side facing the coil. 4C shows the output waveform of R, and (c) and (d) show the output waveforms of the acoustic transducer 14L on the conductor 22 side fixed to the conductor 21 with bolts and nuts.
- Note that (a) and (c) are the outputs measured by passing through the BP (bandpass, filter 1: pass band 20 kHz to 500 kHz) and cutting the frequency components below 20 kHz.
- (B) and (d) are output waveforms of all frequency components up to 500 kHz.
- the output waveform of the acoustic converter 14 L has a smaller amplitude than the output waveform of the acoustic converter 14 R.
- the use of the method of the present invention enables diagnosis and measurement of the tightness of the fastener.
- This method can also be used to detect cracks in honeycomb structures used for bridges, etc., and to judge the quality of welding at welded portions.
- FIG. 26 is a diagram showing a method for measuring the position of a conductor embedded in a non-conductor according to the present invention, wherein (a) shows a conductor embedded in soil 31 which is a non-conductor. Attach the acoustic transducer 14 to the exposed part 3 3 of the water pipe 3 2 (B) is a view as viewed from directly above when placed on the surface 34.
- FIG. 26 is a diagram showing a method for measuring the position of a conductor embedded in a non-conductor according to the present invention, wherein (a) shows a conductor embedded in soil 31 which is a non-conductor. Attach the acoustic transducer 14 to the exposed part 3 3 of the water pipe 3 2 (B) is a view as viewed from directly above when placed on the surface 34.
- Example 10 shows that the position of a conductor embedded in a non-conductor can be measured by the method for measuring the position of a conductor embedded in a non-conductor according to the present invention. .
- Fig. 27 is a diagram showing the results of measuring the position of a water pipe embedded in the soil, (a) when the coil is directly above the water pipe, and (b) when the coil is on the surface of the soil.
- C shows the waveform of the acoustic signal when 60 mm away from the position directly above the water pipe and 18 O mm away from the position directly above the water pipe on the soil surface.
- the acoustic signal intensity is highest when the coil is directly above, and decreases as the position of the coil moves away from directly above.
- the position of the coil is changed and the position where the acoustic signal is maximized is found, there is a pipe just below it.
- FIG. 28 is a diagram showing a method for diagnosing the presence or absence of a break in a conductor embedded in a non-conductor and measuring the position of the break according to the present invention.
- Prestress '' Acoustic transducer 14 is attached to exposed part 4 3 of reinforcing bar 4 2 embedded in long reinforced concrete 4 1 which is concrete, and coil 1 2 is mounted on the surface of long reinforced concrete 4 1.
- Attach apply a magnetic field pulse from coil 12 to induce eddy current on the surface of the rebar, Excite the reinforcing bar 4 2 more.
- the sound generated when the reinforcing bar 42 is excited is transmitted through the reinforcing bar 42, and is detected by the acoustic transducer 14 attached to the exposed portion 43 of the reinforcing bar 42. If the reinforcing bar 42 is torn at the middle 44, the strength of the detected acoustic signal is small, and it can be diagnosed whether or not there is a tear. Further, if the measurement is performed while changing the position of the coil 12 on the surface of the long reinforcing bar 41, the disconnection position 44 can be measured from the position where the presence or absence of the acoustic signal is generated.
- the conductor in a structure including a conductor and a non-conductor covering the conductor, the conductor can be directly and strongly excited by the pulsed electromagnetic force. Exciting the reinforced concrete reinforcement, it is possible to obtain an extremely loud acoustic signal that reflects the corrosion and adhesion of the reinforcement. Regardless of the thickness of concrete and the degree of deterioration, it can be diagnosed and measured reliably without crushing.
- the measurement of the depth and diameter of the covering of the reinforcing bar is also easy and reliable.
Description
Claims
Priority Applications (3)
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JP2002542839A JP3738424B2 (ja) | 2000-11-17 | 2001-11-07 | パルス電磁力による音響診断・測定装置、及びそれらの診断・測定方法 |
AU2002212720A AU2002212720A1 (en) | 2000-11-17 | 2001-11-07 | Device and method for acoustic diagnosis and measurement by pulse electromagnetic force |
US10/416,153 US6962082B2 (en) | 2000-11-17 | 2001-11-07 | Device and method for acoustic diagnosis and measurement by pulse electromagnetic force |
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JP2000351879 | 2000-11-17 | ||
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US (1) | US6962082B2 (ja) |
JP (1) | JP3738424B2 (ja) |
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Cited By (10)
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DE10355297B3 (de) * | 2003-11-21 | 2005-02-17 | Hochschule für Technik und Wirtschaft Dresden (FH) | Einrichtung und Verfahren zur Erkennung von Defekten in Bewehrungen von Betonbauteilen |
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Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07218477A (ja) * | 1994-01-31 | 1995-08-18 | Tomohiko Akuta | 探査装置 |
JP2001194347A (ja) * | 2000-01-17 | 2001-07-19 | Masahiro Nishikawa | 導電体含有構造物の非破壊検査方法 |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4633715A (en) * | 1985-05-08 | 1987-01-06 | Canadian Patents And Development Limited - Societe Canadienne Des Brevets Et D'exploitation Limitee | Laser heterodyne interferometric method and system for measuring ultrasonic displacements |
US5902935A (en) * | 1996-09-03 | 1999-05-11 | Georgeson; Gary E. | Nondestructive evaluation of composite bonds, especially thermoplastic induction welds |
US20040123665A1 (en) * | 2001-04-11 | 2004-07-01 | Blodgett David W. | Nondestructive detection of reinforcing member degradation |
-
2001
- 2001-11-07 JP JP2002542839A patent/JP3738424B2/ja not_active Expired - Lifetime
- 2001-11-07 WO PCT/JP2001/009742 patent/WO2002040959A1/ja active Application Filing
- 2001-11-07 AU AU2002212720A patent/AU2002212720A1/en not_active Abandoned
- 2001-11-07 US US10/416,153 patent/US6962082B2/en not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07218477A (ja) * | 1994-01-31 | 1995-08-18 | Tomohiko Akuta | 探査装置 |
JP2001194347A (ja) * | 2000-01-17 | 2001-07-19 | Masahiro Nishikawa | 導電体含有構造物の非破壊検査方法 |
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WO2005050189A1 (de) * | 2003-11-21 | 2005-06-02 | Hochschule für Technik und Wirtschaft Dresden (FH) | Einrichtung und verfahren zur erkennung von defekten in bewehrungen von betonbauteilen |
JP2005315892A (ja) * | 2004-04-30 | 2005-11-10 | General Electric Co <Ge> | エーロフォイルを超音波検査する方法 |
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JP2018017518A (ja) * | 2016-07-25 | 2018-02-01 | 株式会社Nttファシリティーズ | 腐食度推定方法、腐食度推定装置およびプログラム |
Also Published As
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US20040025593A1 (en) | 2004-02-12 |
AU2002212720A1 (en) | 2002-05-27 |
JPWO2002040959A1 (ja) | 2004-03-25 |
JP3738424B2 (ja) | 2006-01-25 |
US6962082B2 (en) | 2005-11-08 |
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