JPH10213573A - Estimating method for surface layer damage - Google Patents
Estimating method for surface layer damageInfo
- Publication number
- JPH10213573A JPH10213573A JP9014213A JP1421397A JPH10213573A JP H10213573 A JPH10213573 A JP H10213573A JP 9014213 A JP9014213 A JP 9014213A JP 1421397 A JP1421397 A JP 1421397A JP H10213573 A JPH10213573 A JP H10213573A
- Authority
- JP
- Japan
- Prior art keywords
- wave
- frequency
- depth
- flaw
- transmitted wave
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
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Classifications
-
- 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
- G01N29/04—Analysing solids
- G01N29/11—Analysing solids by measuring attenuation of acoustic waves
-
- 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
- G01N2291/048—Transmission, i.e. analysed material between transmitter and receiver
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- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は超音波の表面波を用
いて材料の表層部の探傷を行ない、表層傷の種類と深さ
を推定するようにした表層傷の推定法に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for estimating a surface flaw by detecting a surface layer of a material using an ultrasonic surface wave and estimating the type and depth of the surface flaw.
【０００２】[0002]
【従来の技術】超音波の表面波は材料の表層部を探傷す
る手段として良く知られている。表面波を用いた超音波
探傷の一般的構成は、被検体の表面に表面波を送信する
表面波探触子を用い、その探触子を用いて受信し、傷か
らのエコーの有無から傷の有無を判断するようにしてい
る。表面波は被検体の表面に沿って伝搬する弾性波であ
り、その浸透深さは波長に依存していることが良く知ら
れている。この性質を利用して傷の深さを推定すること
が行われている。2. Description of the Related Art Ultrasonic surface waves are well known as means for detecting flaws on a surface layer of a material. The general configuration of ultrasonic flaw detection using surface waves is to use a surface wave probe that transmits a surface wave to the surface of the subject, receive using that probe, and determine whether or not there is an echo from the flaw. Is determined. It is well known that a surface wave is an elastic wave propagating along the surface of a subject, and its penetration depth depends on the wavelength. Estimation of the depth of a flaw is performed using this property.
【０００３】例えば、特開昭６０−２３５０５６号公報
に示す従来の表面波による欠陥深さの推定方法は、内在
する傷の深さ位置を推定する方法であり、反射法の構成
で広帯域の表面波を用い、高周波の成分ほど表面近傍で
振動していることから深い位置の傷では反射せず、低い
周波数の成分ほど深い位置の傷からも反射することを利
用したものである。しかしながら、本法では開口してい
る傷において、割れの表面からの深さが測定ができない
問題があった。また、反射法のため、超音波ビーム方向
と傷のなす角度が直角から傾いていると反射波が弱くな
り、さらにビームの広がりは周波数に依存しているた
め、深さ位置の推定精度も悪くなるという問題もあっ
た。For example, a conventional method for estimating the depth of a defect by a surface wave disclosed in Japanese Patent Application Laid-Open No. Sho 60-235056 is a method for estimating the depth position of an existing flaw. Using a wave, the higher frequency component vibrates in the vicinity of the surface, so that it is not reflected by a flaw at a deep position, and the lower frequency component is reflected by a flaw at a deep position. However, in this method, there is a problem that the depth from the surface of the crack cannot be measured in the open flaw. In addition, because of the reflection method, if the angle between the ultrasonic beam direction and the flaw is inclined from a right angle, the reflected wave becomes weak, and the spread of the beam depends on the frequency. There was also the problem of becoming.
【０００４】また、特開平１−３１０４８号公報に示す
従来の超音波によるコンクリートの開口き裂深さの測定
方法は、対向させた送信用と受信用探触子を用い、送信
した表面波がき裂に沿ってその先端まで伝搬し、き裂の
先端にてモード変換した横波が受信用探触子に届くまで
の時間とき裂を回り込んだ表面波が受信用探触子に届く
までの時間との差を基にき裂の深さを測定する方法であ
る。しかしながら、本法では非常に弱いモード変換波を
受信する必要があるため、ノイズの多い環境下では使い
にくく、また透過してくる表面波などの様々なエコーと
分離することが難しいため、自動化が困難な問題があっ
た。また、傷形状が凹み状の場合は、き裂先端のような
モード変換が起こらず、適用できないという問題もあっ
た。A conventional method of measuring the depth of an opening crack in concrete using ultrasonic waves disclosed in Japanese Patent Application Laid-Open No. Hei 1-331048 discloses a method of transmitting a transmitted surface wave using a transmitting and receiving probe facing each other. Time until the transverse wave propagated along the crack to its tip and mode-converted at the tip of the crack reaches the receiving probe, and time until the surface wave wrapped around the crack reaches the receiving probe This is a method of measuring the depth of a crack based on the difference between the two. However, this method needs to receive a very weak mode-converted wave, which makes it difficult to use it in a noisy environment and it is difficult to separate it from various echoes such as transmitted surface waves. There was a difficult problem. In addition, when the shape of the flaw is concave, there is also a problem that mode conversion such as the tip of a crack does not occur and cannot be applied.
【０００５】[0005]
【発明が解決しようとする課題】本発明はかかる問題点
を解決するためになされたもので、傷の方向にかかわり
なく、表層傷の種類と深さを自動的に精度良く推定でき
る表層傷の推定法を得ることを目的とする。SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is possible to automatically and accurately estimate the type and depth of a surface flaw regardless of the direction of the flaw. The aim is to obtain an estimation method.
【０００６】[0006]
【課題を解決するための手段】本発明の請求項１の表層
傷の推定法は、所定の周波数の送信波を用い、送信波に
対応した周波数の透過波の減衰量を所定のしきい値と比
較し、該減衰量が所定のしきい値を越えるときは開口傷
と推定し、該減衰量が所定のしきい値を越えないときは
非開口傷と推定するようにしたものである。かかる表層
傷の推定法によれば、送信波に対応した透過波の減衰量
を求めれば、しきい値と比較することにより、被検体の
表層部の傷の種類を容易に高精度に推定することができ
る。According to a first aspect of the present invention, there is provided a method for estimating a surface flaw, wherein a transmission wave having a predetermined frequency is used, and the attenuation of a transmitted wave having a frequency corresponding to the transmission wave is determined by a predetermined threshold value. When the amount of attenuation exceeds a predetermined threshold value, it is estimated that the opening is flawed, and when the amount of attenuation does not exceed the predetermined threshold, it is estimated that the opening is not flawed. According to such a method for estimating a surface layer flaw, if the attenuation of a transmitted wave corresponding to a transmission wave is obtained, the type of the surface layer flaw of the subject can be easily and accurately estimated by comparing with a threshold value. be able to.
【０００７】本発明の請求項２の表層傷の推定法は、異
なる周波数を含む送信波を用い、前記送信波の各周波数
に対応したそれぞれの透過波が、開口傷が浅い場合は高
い周波数側のみが大きく減衰し、開口傷が浅くなるにつ
れて低い周波数まで減衰するという性質から求められた
開口傷の深さと各周波数に対応したそれぞれの透過波の
減衰量との間で相関関係を示す式に基づき、前記送信波
の各周波数に対応したそれぞれの透過波の減衰量から計
算して開口傷の深さを推定するようにしたものである。
かかる表層傷の推定法によれば、送信波の各周波数に対
応したそれぞれの透過波の減衰量を求めれば、所定の式
を計算することにより、被検体の表層部の開口傷の深さ
を容易に高精度に推定することができる。According to a second aspect of the present invention, in the method for estimating a surface flaw, transmission waves including different frequencies are used, and each transmitted wave corresponding to each frequency of the transmission wave is transmitted to a higher frequency side when the aperture flaw is shallow. Is greatly attenuated, and as the aperture flaw becomes shallower, it attenuates to a lower frequency.The equation that shows the correlation between the depth of the aperture flaw and the attenuation of each transmitted wave corresponding to each frequency Based on this, the depth of the opening flaw is estimated by calculating from the attenuation of each transmitted wave corresponding to each frequency of the transmission wave.
According to such a method for estimating surface flaws, if the attenuation of each transmitted wave corresponding to each frequency of the transmitted wave is obtained, the depth of the opening flaw on the surface layer of the subject is calculated by calculating a predetermined formula. It can be easily and accurately estimated.
【０００８】本発明の請求項３の表層傷の推定法は、異
なる周波数を含む送信波を用い、前記送信波の各周波数
に対応したそれぞれの透過波が、深さ位置が浅いほど高
い周波数の減衰は小さく、深くなるほど低い周波数の減
衰も小さくなるという性質から求められた非開口傷の深
さと、各周波数に対応したそれぞれの透過波の減衰量と
の間で相関関係を示す式に基づき、前記送信波の各周波
数に対応したそれぞれの透過波の減衰量から計算して非
開口傷の深さを推定するようにしたものである。かかる
表層傷の推定法によれば、送信波の各周波数に対応した
それぞれの透過波の減衰量を求めれば、所定の式を計算
することにより、被検体の表層部の非開口傷の深さを容
易に高精度に推定することができる。According to a third aspect of the present invention, there is provided a method for estimating surface flaws, wherein transmission waves having different frequencies are used, and each transmitted wave corresponding to each frequency of the transmission waves has a higher frequency as the depth position becomes shallower. Attenuation is small, based on the equation that shows the correlation between the depth of the non-aperture flaw, which is determined from the property that the deeper the depth is, the lower the attenuation of the lower frequency is, and the attenuation of each transmitted wave corresponding to each frequency. The depth of the non-aperture flaw is estimated by calculating from the attenuation of each transmitted wave corresponding to each frequency of the transmission wave. According to such a method of estimating a surface flaw, if the attenuation of each transmitted wave corresponding to each frequency of the transmission wave is obtained, the depth of the non-opening flaw in the surface layer of the subject is calculated by calculating a predetermined formula. Can be easily and accurately estimated.
【０００９】本発明の請求項４の表層傷の推定法は、所
定の周波数の送信波を用い、前記送信波に対応した周波
数の透過波の遅延時間が凹みの深さが深くなるほど長く
なるという性質から求められた凹みの深さと該透過波の
周波数の遅延時間との間で相関関係を示す式に基づき、
前記送信波に対応した透過波の周波数の遅延時間から計
算して凹みの深さを推定するようにしたものである。か
かる表層傷の推定法によれば、送信波の所定の周波数に
対応した遅延時間を求めれば、所定の式を計算すること
により、被検体の表層部の凹みの深さを容易に高精度に
推定することができる。In the method for estimating a surface damage according to a fourth aspect of the present invention, a transmission wave having a predetermined frequency is used, and a delay time of a transmitted wave having a frequency corresponding to the transmission wave increases as the depth of the dent increases. Based on an equation showing a correlation between the depth of the dent determined from the properties and the delay time of the frequency of the transmitted wave,
The depth of the dent is estimated by calculating from the delay time of the frequency of the transmitted wave corresponding to the transmission wave. According to such a method for estimating a surface layer flaw, if a delay time corresponding to a predetermined frequency of a transmission wave is obtained, the depth of the dent of the surface layer of the subject can be easily and accurately determined by calculating a predetermined equation. Can be estimated.
【００１０】[0010]
実施の形態１．図１は本発明の表層傷の推定方法を実施
する実施の形態１の装置の構成を示すブロック図、図２
は同装置を用いて測定した開口傷及び非開口傷に対する
透過波の減衰量の測定結果を示す図、図３は同装置を用
いて測定した開口傷に対する透過波の減衰量の比と傷の
深さ／波長との関係を示すグラフ、図４は同装置を用い
て測定した非開口傷に対する透過波の減衰量の比と傷の
深さ／波長との関係を示すグラフ、図５は本発明の実施
形態１の表層傷の推定方法を示すフローチャートであ
る。Embodiment 1 FIG. FIG. 1 is a block diagram showing the configuration of an apparatus for carrying out the method for estimating a surface wound according to the first embodiment of the present invention.
FIG. 3 is a graph showing the results of measurement of the amount of attenuation of a transmitted wave with respect to an open wound and a non-aperture wound measured using the same device. FIG. FIG. 4 is a graph showing the relationship between the depth / wavelength, FIG. 4 is a graph showing the relationship between the ratio of the attenuation of the transmitted wave to the non-open wound and the depth / wavelength of the wound measured using the same apparatus, and FIG. It is a flowchart which shows the estimation method of the surface layer wound of Embodiment 1 of this invention.
【００１１】図１において、１はトーンバースト波を発
生させるバースト波送信器であり、トーンバースト波の
周波数と波数を各々任意に定めることができるようにな
っている。トーンバースト波の周波数は１ＭＨｚから９
ＭＨｚまで可変できるものとし、その出力は２００Ｖｐ
ｐとした。２は送信用の表面波探触子で、被検体３にト
ーンバースト波に基づく表面波を送信するものであり、
表面波探触子２と被検体３とは水などで音響接触されて
いる。４は被検体３の傷であり、受信用の表面波探触子
５と送信用の表面波探触子２の間に位置する時に本発明
は適用できる。送信用と受信用の表面波探触子２、５に
は、帯域が０．５〜９ＭＨｚの広帯域のものを用いた。
６は透過波の強度と透過時間を測定するための受信器で
あり、透過波の透過時間は図には書いていないが送信器
から送信タイミング時間に同期した同期信号を受けその
信号を基に測定するようにしている。In FIG. 1, reference numeral 1 denotes a burst wave transmitter for generating a tone burst wave, which can arbitrarily determine the frequency and wave number of the tone burst wave. The frequency of the tone burst wave is from 1 MHz to 9
MHz and the output is 200Vp
p. A transmission surface wave probe 2 transmits a surface wave based on a tone burst wave to the subject 3.
The surface wave probe 2 and the subject 3 are in acoustic contact with water or the like. Reference numeral 4 denotes a scratch on the subject 3, and the present invention can be applied when it is located between the surface acoustic wave probe 5 for reception and the surface acoustic wave probe 2 for transmission. As the surface wave probes 2 and 5 for transmission and reception, those having a band of 0.5 to 9 MHz were used.
Reference numeral 6 denotes a receiver for measuring the intensity and transmission time of the transmitted wave. The transmission time of the transmitted wave is not shown in the figure, but receives a synchronization signal synchronized with the transmission timing time from the transmitter, and based on the signal. I try to measure.
【００１２】次に、本発明の表層傷の推定方法を実施す
る実施の形態１の装置を用いて実際に測定した結果につ
いて述べる。まず傷に割れ状の人工傷を用い、その深さ
を推定した。開口した割れ（以下、「開口傷」という）
の深さは０．１ｍｍ、０．３ｍｍ、０．５ｍｍとし、非
開口の割れ（以下、「非開口傷」という）は深さ０．３
ｍｍで位置は０．１ｍｍ、０．３ｍｍとした。バースト
波の周波数は１ＭＨｚ、３ＭＨｚ、５ＭＨｚとした。Next, the results of actual measurement using the apparatus according to the first embodiment for implementing the method for estimating surface damage according to the present invention will be described. First, a crack-shaped artificial wound was used, and the depth was estimated. Open cracks (hereinafter referred to as "open wounds")
Have a depth of 0.1 mm, 0.3 mm, and 0.5 mm, and a non-opening crack (hereinafter referred to as a “non-opening flaw”) has a depth of 0.3 mm.
The positions were 0.1 mm and 0.3 mm in mm. The frequency of the burst wave was 1 MHz, 3 MHz, and 5 MHz.
【００１３】図２は各々の送信波に対応した透過波にお
ける被検体の健全部に対する傷部の減衰量を測定した結
果であり、開口傷では傷が浅い場合は高い周波数側のみ
大きく減衰し、傷が深くなるにつれて低い周波数まで減
衰するようになった。また、非開口傷では、深さ位置が
浅いほど高い周波数の減衰は小さく、深くなるほど低い
周波数の減衰も小さくなった。この結果から、例えば次
のように傷を推定することができる。まず、傷の種類に
ついては、しきい値を−５ｄＢと定める。傷が開口して
いるか否かは、５ＭＨｚでの減衰量を調べる。しきい値
より減衰量が大きければ開口傷、小さければ非開口傷で
ある。FIG. 2 shows the result of measurement of the attenuation of a flaw in the transmitted wave corresponding to each transmitted wave with respect to the healthy part of the subject. As the wound became deeper, it attenuated to lower frequencies. In the case of the non-opening flaw, the attenuation at a higher frequency was smaller as the depth position was smaller, and the attenuation at a lower frequency was smaller as the depth position was deeper. From this result, for example, a flaw can be estimated as follows. First, the threshold value is set to -5 dB for the type of flaw. The amount of attenuation at 5 MHz is checked to determine whether the flaw is open. If the amount of attenuation is larger than the threshold value, it is an opening flaw, and if it is smaller, it is a non-opening flaw.
【００１４】開口傷の場合の深さは次のようになる。全
ての周波数での減衰量がしきい値を越えていれば０．５
ｍｍ以上、３ＭＨｚと５ＭＨｚでの減衰量がしきい値を
越えていれば０．３ｍｍ〜０．５ｍｍ、５ＭＨｚのみし
きい値を越えていれば０．１ｍｍ〜０．３ｍｍである。
また、非開口傷の深さ位置は次のようになる。１ＭＨｚ
と３ＭＨｚでの減衰量がしきい値を越えていれば０．１
ｍｍ以下、１ＭＨｚでの減衰量のみしきい値を越えてい
れば０．３ｍｍ〜０．１ｍｍである。さらに、傷に凹み
の人工傷を用い、その深さを推定した。ここでは図６の
（ａ）に示すような形状の傷を用い、その深さは０．２
ｍｍ〜１ｍｍとし、バースト波の周波数は５ＭＨｚとし
た。The depth in the case of an opening flaw is as follows. 0.5 if the attenuation at all frequencies exceeds the threshold
If the attenuation amount at 3 MHz and 5 MHz exceeds the threshold value, the distance is 0.3 mm to 0.5 mm, and when the attenuation amount exceeds the threshold value only at 5 MHz, the distance is 0.1 mm to 0.3 mm.
The depth position of the non-opening flaw is as follows. 1MHz
And 0.1 if the attenuation at 3 MHz exceeds the threshold.
mm or less and 0.3 mm to 0.1 mm if only the attenuation at 1 MHz exceeds the threshold value. Furthermore, the depth of the wound was estimated by using a dent artificial wound. Here, a scratch having a shape as shown in FIG.
mm to 1 mm, and the frequency of the burst wave was 5 MHz.
【００１５】更に、その後実験を繰り返した結果、開口
傷の深さと透過波の減衰量について、概略、図３のグラ
フに示すような関係があることを見い出した。また、非
開口傷の深さと透過波の減衰量については、図４のグラ
フに示すような関係があることを見い出した。図３及び
図４のグラフにおいて、縦軸に透過波減衰量の比をと
り、横軸に深さ／波長をとっている。なお、透過波減衰
量の比とは健全面に対する透過波の減衰量の比をいう。Further, as a result of repeating the experiment thereafter, it was found that the relationship between the depth of the opening flaw and the amount of attenuation of the transmitted wave was approximately as shown in the graph of FIG. In addition, it has been found that the relationship between the depth of the non-opening flaw and the attenuation of the transmitted wave is as shown in the graph of FIG. In the graphs of FIGS. 3 and 4, the vertical axis represents the ratio of the attenuation of the transmitted wave, and the horizontal axis represents the depth / wavelength. The ratio of the transmitted wave attenuation refers to the ratio of the transmitted wave attenuation to the sound surface.
【００１６】開口傷については、図３のグラフを見ると
分かるように、深さ／波長が０．５までは比較的直線的
に透過波が減衰し、あるところからサチュレーションす
ること分かる。そこで、この直線領域においては、開口
傷の深さと各周波数に対応したそれぞれの透過波の減衰
量との間で相関関係が成立し、特定の周波数に対応した
透過波の減衰量が分かれば開口傷の深さを推定すること
ができる。即ち、開口傷の場合の直線領域の式は、周波
数ｆの時の透過波減衰量をα（ｆ）とすると、 深さ／波長＝０．６（１−α（ｆ）） となり、波長＝表面波音速／音速周波数であるから、表
面波音速を3000m/s とすると、深さｈは次式で表され
る。ｈ＝１．８（１−α（ｆ））／ｆ 但し、透過波減
衰量の比は０．５＜α（ｆ）＜１の範囲で推定すること
ができる。As can be seen from the graph of FIG. 3, the transmitted wave attenuates the transmitted wave relatively linearly up to a depth / wavelength of 0.5 and saturates from a certain point. Therefore, in this linear region, a correlation is established between the depth of the opening flaw and the attenuation of each transmitted wave corresponding to each frequency, and if the attenuation of the transmitted wave corresponding to a specific frequency is known, the aperture is determined. The depth of the wound can be estimated. That is, the equation of the linear region in the case of an opening flaw is as follows: When the transmitted wave attenuation at the frequency f is α (f), depth / wavelength = 0.6 (1−α (f)), and wavelength = Since the sound velocity is the surface wave sound speed / the sound speed frequency, if the surface wave sound speed is 3000 m / s, the depth h is expressed by the following equation. h = 1.8 (1−α (f)) / f However, the ratio of the attenuation of the transmitted wave can be estimated in the range of 0.5 <α (f) <1.
【００１７】また、非開口傷の深さ位置については、図
４のグラフを見ると分かるように、深さ／波長が０．３
までは比較的直線的に透過波の減衰が減少し、あるとこ
ろからサチュレーションすること分かる。そこで、この
直線領域においては、非開口傷の深さ位置と、各周波数
に対応したそれぞれの透過波の減衰量との間で相関関係
が成立し、特定の周波数に対応した透過波の減衰量が分
かれば非開口傷の深さ位置を推定することができる。即
ち、非開口傷の場合の直線領域の式は、周波数ｆの時の
透過波減衰量をα（ｆ）とすると、非開口傷の深さ位置
ｄは次式で表される。ｄ＝１．８α（ｆ））／ｆ 但
し、透過波減衰量の比は０＜α（ｆ）＜０．５の範囲で
推定することができる。As can be seen from the graph of FIG. 4, the depth position of the non-opening flaw is 0.3 / depth / wavelength.
It can be seen that the attenuation of the transmitted wave decreases relatively linearly, and saturation occurs from a certain point. Therefore, in this linear region, a correlation is established between the depth position of the non-opening flaw and the attenuation of each transmitted wave corresponding to each frequency, and the attenuation of the transmitted wave corresponding to a specific frequency. , The depth position of the non-opening flaw can be estimated. That is, in the equation of the linear region in the case of the non-aperture flaw, the depth position d of the non-aperture flaw is expressed by the following equation, where the transmitted wave attenuation at the frequency f is α (f). d = 1.8α (f)) / f However, the ratio of the attenuation of the transmitted wave can be estimated in the range of 0 <α (f) <0.5.
【００１８】そこで、上記式に基づき、３つの周波数か
ら開口傷と非開口傷の種別の判定と、これらの傷のある
程度の深さ範囲の推定について、図５のフローチャート
に基づいて説明する。スタートし（ステップＳ１）、透
過波の周波数が９ＭＨｚの場合、透過波減衰量の比の
０．５をしきい値として開口傷か非開口傷かを判定す
る。即ち、透過波減衰量の比が０．５以上であるときは
開口傷があると判定し、透過波減衰量の比が０．５未満
であるときは非開口傷と判定することができるが、透過
波の周波数が９ＭＨｚの場合は開口傷と非開口傷の深さ
についていはいずれも上記式に基づいて計算により求め
ることはできない（ステップＳ２）。The determination of the types of open and non-open flaws from the three frequencies based on the above equation and the estimation of a certain depth range of these flaws will be described with reference to the flowchart of FIG. The process is started (step S1), and when the frequency of the transmitted wave is 9 MHz, it is determined whether or not the wound is an opening flaw or a non-opening flaw using the ratio of the attenuation of the transmitted wave of 0.5 as a threshold. That is, when the ratio of the transmitted wave attenuation is 0.5 or more, it is determined that there is an opening flaw, and when the ratio of the transmitted wave attenuation is less than 0.5, it can be determined that there is no opening flaw. When the frequency of the transmitted wave is 9 MHz, the depths of the open flaw and the non-aperture flaw cannot be obtained by calculation based on the above equation (step S2).
【００１９】次に、透過波の周波数が９ＭＨｚで透過波
減衰量の比が０．５未満のときで、透過波の周波数が３
ＭＨｚで透過波減衰量の比が０．５以上の場合は開口傷
の深さｈについて上記式に基づいて計算により求めるこ
とができ（ステップＳ３、４）、透過波の周波数が３Ｍ
Ｈｚで透過波減衰量の比が０．５未満の場合は開口傷の
深さｈについて上記式に基づいて計算により求めること
ができない。更に、透過波の周波数が３ＭＨｚで透過波
減衰量の比が０．５未満のときで、透過波の周波数が１
ＭＨｚで透過波減衰量の比が０．５以上の場合は開口傷
の深さｈについて上記式に基づいて計算により求めるこ
とができ（ステップＳ５、６）、透過波の周波数が１Ｍ
Ｈｚで透過波減衰量の比が０．５未満の場合は開口傷の
深さｈは０．９以上と推定する（ステップＳ７）。Next, when the frequency of the transmitted wave is 9 MHz and the ratio of the attenuation of the transmitted wave is less than 0.5, and the frequency of the transmitted wave is 3
When the ratio of the attenuation of the transmitted wave in MHz is 0.5 or more, the depth h of the opening flaw can be obtained by calculation based on the above equation (steps S3 and S4), and the frequency of the transmitted wave is 3M.
If the ratio of the attenuation of the transmitted wave at Hz is less than 0.5, the depth h of the opening flaw cannot be obtained by calculation based on the above equation. Further, when the frequency of the transmitted wave is 3 MHz and the ratio of the attenuation of the transmitted wave is less than 0.5, the frequency of the transmitted wave is 1
If the ratio of the attenuation of the transmitted wave in MHz is 0.5 or more, the depth h of the opening flaw can be obtained by calculation based on the above equation (steps S5 and S6), and the frequency of the transmitted wave is 1M.
If the ratio of the transmitted wave attenuation at Hz is less than 0.5, the depth h of the opening flaw is estimated to be 0.9 or more (step S7).
【００２０】他方、透過波の周波数が９ＭＨｚで透過波
減衰量の比が０．５以上のときで、透過波の周波数が３
ＭＨｚで透過波減衰量の比が０．５未満の場合は非開口
傷の深さｈについて上記式に基づいて計算により求める
ことができ（ステップＳ８、９）、透過波の周波数が３
ＭＨｚで透過波減衰量の比が０．５以上の場合は非開口
傷の深さ位置ｄについて上記式に基づいて計算により求
めることができない。次に、透過波の周波数が３ＭＨｚ
で透過波減衰量の比が０．５以上のときで、透過波の周
波数が１ＭＨｚで透過波減衰量の比が０．５未満の場合
は非開口傷の深さ位置ｄについて上記式に基づいて計算
により求めることができ（ステップＳ１０、１１）、透
過波の周波数が１ＭＨｚで透過波減衰量の比が０．５以
上の場合は非開口傷はなく、健全部であると推定する
（ステップＳ１２）。このように、３つの周波数から開
口傷と非開口傷の種別の判定と、これらの傷のある程度
の深さ範囲の推定について、上記式に基づいて計算によ
り求めることができるから、被検体の表層部の開口及び
非開口傷の種別の判定と、これらの傷の深さを容易に高
精度に推定することができる。On the other hand, when the frequency of the transmitted wave is 9 MHz and the ratio of the attenuation of the transmitted wave is 0.5 or more, the frequency of the transmitted wave is 3
If the ratio of the attenuation of the transmitted wave in MHz is less than 0.5, the depth h of the non-opening flaw can be obtained by calculation based on the above equation (steps S8 and S9), and the frequency of the transmitted wave is 3
When the ratio of the attenuation of the transmitted wave in MHz is 0.5 or more, the depth position d of the non-opening flaw cannot be obtained by calculation based on the above equation. Next, the frequency of the transmitted wave is 3 MHz.
When the ratio of the transmitted wave attenuation is 0.5 or more, and the frequency of the transmitted wave is 1 MHz and the ratio of the transmitted wave attenuation is less than 0.5, the depth position d of the non-opening flaw is calculated based on the above equation. If the transmitted wave frequency is 1 MHz and the ratio of the transmitted wave attenuation is 0.5 or more, there is no non-opening flaw and it is estimated that the part is sound (steps S10 and S11). S12). As described above, the determination of the types of the open wound and the non-open wound and the estimation of the depth range of these wounds to some extent from the three frequencies can be obtained by calculation based on the above formula. It is possible to easily determine the types of the opening and non-opening flaws of the part and to estimate the depths of these flaws with high accuracy.
【００２１】次に、被検体の表層部の凹みの傷の深さの
推定法について説明する。図６の（ａ）は被検体の表層
部の凹みの傷の状態を示し、図６の（ｂ）に示すグラフ
は縦軸に透過波の遅延時間をとり、横軸に凹みの傷の深
さをとっている。図７は被検体の健全部と凹みの傷とに
対する透過波の遅延時間の違いを示す波形図である。図
７の波形図は、まず被検体の健全部での透過波を測定
し、送信した時間からの経過時間ｔ１を求めておく、次
に凹みの傷を測定したときの透過波の送信からの経過時
間ｔ２を求め、両者から遅延時間はｔ２−ｔ１で求めて
いる。また、凹みの傷の深さの推定は、予め図６の
（ｂ）に示すグラフに示すように、被検体の表層部の凹
みの傷に対する所定の周波数の透過波の遅延時間を測定
し、凹み状の傷の深さと遅延時間との関係を表したもの
である。Next, a method for estimating the depth of a dent wound in the surface layer of a subject will be described. FIG. 6 (a) shows the state of a dent in the surface layer of the subject, and the graph shown in FIG. 6 (b) shows the delay time of the transmitted wave on the vertical axis and the depth of the dent in the horizontal axis. I'm taking it. FIG. 7 is a waveform diagram showing a difference in delay time of a transmitted wave with respect to a healthy part and a dent wound of a subject. The waveform diagram of FIG. 7 shows that the transmitted wave in the healthy part of the subject is measured first, and the elapsed time t1 from the transmission time is obtained, and then the transmitted wave when the dent is measured is measured. The elapsed time t2 is obtained, and the delay time is obtained from the two by t2-t1. Further, the depth of the dent flaw is estimated by measuring the delay time of a transmitted wave of a predetermined frequency with respect to the dent flaw on the surface layer of the subject, as shown in a graph of FIG. It shows the relationship between the depth of a dent-shaped flaw and the delay time.
【００２２】このグラフを見ると、凹みの傷が深くなる
ほど透過波の遅延時間が長くなっており、両者の間には
直線的な相関関係があることが分かり、両者の相関関係
を次の式で表すことができ、その式を計算することによ
り、遅延時間から凹みの傷の深さを求めることができ
る。 Ｄ＝ｋ・ｔ ここで、Ｄは凹みの傷の深さ、ｋは係数であり、実験的
に求めたもので、ここでは０．２５である。ｔは遅延時
間である。From this graph, it can be seen that the deeper the dent is, the longer the delay time of the transmitted wave is, and that there is a linear correlation between the two. The depth of the dent flaw can be obtained from the delay time by calculating the equation. D = k · t Here, D is the depth of the dent, and k is a coefficient, which is experimentally obtained, and is 0.25 in this case. t is a delay time.
【００２３】このように凹みの傷が深くなるほど透過波
の遅延時間が長くなるのは、表面波は割れでは反射しや
すく、凹みの傷ではそのまま透過しやすい性質から、割
れでは透過波が減衰するので上記に述べた関係から推定
できるのに対し、凹みの傷では透過波がほとんど減衰し
ないため上記に述べた関係が適用できない。しかし、健
全部に比較して凹みの傷の表面に沿って伝搬する分、透
過波が遅れるため、透過波の遅延時間を基に凹みの傷の
深さを推定することができる。なお透過波を用いている
ので、傷の方向に関りなく以上の深さ推定を行なうこと
ができる。As described above, the longer the depth of the dent, the longer the delay time of the transmitted wave is. The surface wave is easily reflected by the crack, and easily transmitted by the dent, and the transmitted wave is attenuated by the crack. Therefore, while the above-mentioned relation can be estimated, the above-mentioned relation cannot be applied to the dent flaw because the transmitted wave is hardly attenuated. However, the transmitted wave is delayed by an amount corresponding to the propagation along the surface of the dent flaw as compared with the sound part, so that the depth of the dent flaw can be estimated based on the delay time of the transmitted wave. Since the transmitted wave is used, the above depth estimation can be performed regardless of the direction of the flaw.
【００２４】なお、以上の実施の形態では、トーンバー
スト波の周波数を切換えるようにしたが、例えば３つの
トーンバースト波を加算した送信信号を用い、受信では
それらの周波数に対応したバンドパスフィルタで３つの
信号に分離するようにしても良く、また受信ではバンド
パスフィルタを使わずデジタル的にＦＦＴなどで周波数
解析を行っても良く、また透過波の解析に用いる周波数
は３つ以上でも良い。In the above embodiment, the frequency of the tone burst wave is switched. However, for example, a transmission signal obtained by adding three tone burst waves is used, and a band pass filter corresponding to those frequencies is used for reception. The signal may be separated into three signals, the frequency may be digitally analyzed by FFT or the like without using a band-pass filter in reception, and three or more frequencies may be used for the analysis of the transmitted wave.
【００２５】実施の形態２．次に、本発明の実施の形態
２について説明する。図８は本発明の表層傷の推定方法
を実施する実施の形態２の装置の構成を示すブロック
図、図９は同装置を用いて測定した開口傷及び非開口傷
に対する透過波の時間一周波数分布を示す図、図１０は
同装置を用いて測定した凹みの傷に対する透過波の時間
−周波数分布を示す図、図１１は同装置を用いて測定し
た凹みの傷に対する透過波の遅延時間の波形図である。
図８において、７は広帯域パルス波を発生させるパルス
波送信器であり、パルス波の幅は５ｎｓ、出力電圧は２
００Ｖである。２〜５は実施の形態１と同じである。８
は透過波を時間−周波数解析するための受信器であり、
透過波を増幅した後、サンプリング周波数５０ＭＨｚで
Ａ／Ｄ変換し、そのデータをＦＦＴ（高速フーリエ変
換）を用いて時間−周波数解析するようになっている。Embodiment 2 Next, a second embodiment of the present invention will be described. FIG. 8 is a block diagram showing a configuration of an apparatus for carrying out the method for estimating a surface damage according to the second embodiment of the present invention. FIG. FIG. 10 is a diagram showing a distribution, FIG. 10 is a diagram showing a time-frequency distribution of a transmitted wave with respect to a dent scratch measured using the same device, and FIG. It is a waveform diagram.
In FIG. 8, reference numeral 7 denotes a pulse wave transmitter for generating a broadband pulse wave, the width of the pulse wave is 5 ns, and the output voltage is 2
00V. 2 to 5 are the same as in the first embodiment. 8
Is a receiver for time-frequency analysis of the transmitted wave,
After amplifying the transmitted wave, A / D conversion is performed at a sampling frequency of 50 MHz, and the data is subjected to time-frequency analysis using FFT (Fast Fourier Transform).
【００２６】その時間−周波数解析の方法は、信号の解
析したい時間範囲に窓関数をかけてその範囲のみ取り出
してＦＦＴし、その時間範囲をわずかずつずらしていく
方法としたが、ウェーブレット処理など他の時間−周波
数解析方法でもよい。ここでは窓関数にはハミング窓を
用い、窓の幅は０．４μｓとした。窓幅内のデータ点数
は２０点であるが、そのデータに０データを足して１０
２４点にしてＦＦＴを行った。次に、実際に測定した結
果について述べる。まず、実施の形態１と同様に、割れ
状の人工傷を用い、その深さを推定した。開口傷の深さ
は０．１ｍｍ、０．３ｍｍ、０．５ｍｍとし、非開口傷
の深さは０．３ｍｍで、位置は０．１ｍｍ、０．３ｍｍ
である。In the time-frequency analysis method, a window function is applied to a time range in which a signal is to be analyzed, only the range is extracted and FFT is performed, and the time range is shifted slightly. Time-frequency analysis method. Here, a Hamming window was used as the window function, and the width of the window was 0.4 μs. The number of data points within the window width is 20, but 0 data is added to the data to obtain 10 points.
FFT was performed with 24 points. Next, the results of actual measurement will be described. First, as in the first embodiment, a crack-shaped artificial wound was used, and its depth was estimated. The depth of the open wound is 0.1 mm, 0.3 mm, 0.5 mm, and the depth of the non-open wound is 0.3 mm, and the position is 0.1 mm, 0.3 mm.
It is.
【００２７】図９は解析した透過波の時間−周波数分布
であり、スペクトラムの強さに応じて等高線表示されて
いる。傷の深さに応じて時間−周波数分布が変化した。
ここで、周波数１ＭＨｚ、３ＭＨｚ、５ＭＨｚの時のス
ペクトラムの最大値を求めると、その関係は先の図２と
同様になった。よって、その結果から傷の深さや深さ位
置を推定することができる。また、その後実験を繰り返
した結果、透過波の時間−周波数分布についても、開口
傷及び非開口傷の深さと透過波の減衰量の関係は、実施
の形態１における図３及び図４のグラフに示すのと同様
な関係があることを見い出した。FIG. 9 shows a time-frequency distribution of the analyzed transmitted wave, which is indicated by contour lines according to the intensity of the spectrum. The time-frequency distribution changed according to the depth of the wound.
Here, when the maximum value of the spectrum at the frequency of 1 MHz, 3 MHz, and 5 MHz was obtained, the relationship was similar to that of FIG. Therefore, the depth and depth position of the flaw can be estimated from the result. Further, as a result of repeating the experiment, the relationship between the depth of the opening flaw and the non-aperture flaw and the attenuation of the transmitted wave is also shown in the graphs of FIG. 3 and FIG. We found that there was a similar relationship as shown.
【００２８】これは、実施の形態１では、複数のトーン
バースト波の周波数を切換えるようにしていたが、この
実施の形態１では、発信側で１つのパルス波を用い、受
信側でデジタル的にＦＦＴなどで周波数解析を行い、透
過波の解析に用いる周波数を３つ選んだだけの違いしか
実質的にはないからである。従って、受信側で透過波の
解析に用いる選んだ３つの周波数の透過波の減衰量が求
められれば、実施の形態１と同様の式により、計算で３
つの周波数から開口傷と非開口傷の種別の判定とある程
度の深さ範囲の推定について求めることができることに
なる。In the first embodiment, the frequency of a plurality of tone burst waves is switched. In the first embodiment, one pulse wave is used on the transmitting side and digitally on the receiving side. This is because frequency analysis is performed by FFT or the like, and only a difference of three frequencies used for analysis of the transmitted wave is substantially obtained. Therefore, if the attenuation of the transmission wave of the selected three frequencies used for the analysis of the transmission wave on the receiving side is obtained, 3 is calculated by the same formula as in the first embodiment.
From the two frequencies, it is possible to determine the types of the opening flaw and the non-opening flaw and estimate a certain depth range.
【００２９】また、被検体の表層部の凹みの傷の深さの
推定法についても、図１０に示すように解析した透過波
の時間−周波数分布をみると、傷が深くなるほど高い周
波数は遅延するようになった。そこで、周波数５ＭＨｚ
の時にスペクトラムの値が最大となる時間を求め、健全
部の時の時間に対する遅延時間を求めた結果、遅延時間
と深さの関係は実施の形態１の図６と同様になった。従
って、この結果から、遅延時間が求められれば、実施の
形態１と同様の式を計算することにより、凹みの傷の深
さを推定することができる。なお、図１１の波形図は、
実施の形態１の図７と同様に遅延時間を示すものであ
る。As for the method of estimating the depth of a dent in the dent of the surface layer of the subject, the time-frequency distribution of the transmitted wave analyzed as shown in FIG. It was way. Therefore, frequency 5MHz
At the time, the time at which the value of the spectrum becomes the maximum is obtained, and the delay time with respect to the time of the sound part is obtained. As a result, the relationship between the delay time and the depth is the same as that of FIG. Therefore, if the delay time is obtained from this result, the depth of the dent flaw can be estimated by calculating the same equation as in the first embodiment. Note that the waveform diagram of FIG.
8 shows a delay time as in FIG. 7 of the first embodiment.
【００３０】なお、以上の実施例では、時間−周波数解
析にデジタル的な処理を用いたが、受信した信号を例え
ば３つのバンドパスフィルタで分けるようにして時間−
周波数分布を求めてもよく、また解析に用いる周波数は
３つ以上でもよい。In the above embodiment, digital processing is used for time-frequency analysis. However, time-frequency analysis is performed by dividing a received signal by, for example, three band-pass filters.
A frequency distribution may be obtained, and three or more frequencies may be used for analysis.
【００３１】[0031]
【発明の効果】以上説明したように、本発明の請求項１
の表層傷の推定法によれば、所定の周波数の送信波を用
い、送信波に対応した周波数の透過波の減衰量を所定の
しきい値と比較し、該減衰量が所定のしきい値を越える
ときは開口傷と推定し、該減衰量が所定のしきい値を越
えないときは非開口傷と推定するようにしたものであ
り、送信波に対応した透過波の減衰量を求めてしきい値
と比較することにより、被検体の表層部の傷の種類を容
易に高精度に判定できるという効果を有する。As described above, according to the first aspect of the present invention,
According to the method for estimating a surface flaw, a transmission wave having a predetermined frequency is used, the attenuation of a transmitted wave having a frequency corresponding to the transmission wave is compared with a predetermined threshold, and the attenuation is determined by a predetermined threshold. When the attenuation exceeds a predetermined threshold value, the aperture is estimated to be non-aperture, and the attenuation of the transmitted wave corresponding to the transmission wave is calculated. By comparing with the threshold value, there is an effect that the type of the scratch on the surface layer of the subject can be easily and accurately determined.
【００３２】また、本発明の請求項２の表層傷の推定法
によれば、異なる周波数を含む送信波を用い、前記送信
波の各周波数に対応したそれぞれの透過波が、開口傷が
浅い場合は高い周波数側のみが大きく減衰し、開口傷が
浅くなるにつれて低い周波数まで減衰するという性質か
ら求められた開口傷の深さと各周波数に対応したそれぞ
れの透過波の減衰量との間で相関関係を示す式に基づ
き、前記送信波の各周波数に対応したそれぞれの透過波
の減衰量から計算して開口傷の深さを推定するようにし
たものであり、送信波の各周波数に対応したそれぞれの
透過波の減衰量を求めて所定の式を計算することによ
り、被検体の表層部の開口傷の深さを容易に高精度に推
定できるという効果を有する。According to the method for estimating a surface flaw according to a second aspect of the present invention, when transmission waves having different frequencies are used and each transmitted wave corresponding to each frequency of the transmission wave has a shallow aperture flaw, Is the correlation between the depth of the opening flaw, which is determined from the property that only the high frequency side attenuates greatly, and the attenuation decreases to the lower frequency as the opening flaw becomes shallower, and the attenuation of each transmitted wave corresponding to each frequency. Based on the equation, the depth of the opening flaw is estimated by calculating from the attenuation of each transmitted wave corresponding to each frequency of the transmission wave, and each corresponding to each frequency of the transmission wave By calculating the predetermined equation by calculating the attenuation of the transmitted wave, it is possible to easily and accurately estimate the depth of the opening flaw in the surface layer of the subject.
【００３３】さらに、本発明の請求項３の表層傷の推定
法によれば、異なる周波数を含む送信波を用い、前記送
信波の各周波数に対応したそれぞれの透過波が、深さ位
置が浅いほど高い周波数の減衰は小さく、深くなるほど
低い周波数の減衰も小さくなるという性質から求められ
た非開口傷の深さと各周波数に対応したそれぞれの透過
波の減衰量との間で相関関係を示す式に基づき、前記送
信波の各周波数に対応したそれぞれの透過波の減衰量か
ら計算して非開口傷の深さを推定するようにしたもので
あり、送信波の各周波数に対応したそれぞれの透過波の
減衰量を求めて所定の式を計算することにより、被検体
の表層部の非開口傷の深さを容易に高精度に推定すでき
るという効果を有する。Further, according to the method for estimating a surface flaw according to claim 3 of the present invention, transmission waves having different frequencies are used, and each transmitted wave corresponding to each frequency of the transmission waves has a shallow depth position. The equation that shows the correlation between the depth of non-aperture flaws and the attenuation of each transmitted wave corresponding to each frequency, determined from the property that the attenuation of higher frequencies decreases as the frequency increases and the attenuation of lower frequencies decreases as the depth increases. Based on the above, the depth of the non-aperture flaw is estimated by calculating from the attenuation of each transmission wave corresponding to each frequency of the transmission wave, and the transmission corresponding to each frequency of the transmission wave is calculated. By calculating a predetermined equation by calculating the amount of wave attenuation, the depth of the non-opening flaw in the surface layer of the subject can be easily and accurately estimated.
【００３４】さらにまた、本発明の請求項４の表層傷の
推定法は、所定の周波数の送信波を用い、前記送信波に
対応した周波数の透過波の遅延時間が凹みの深さが深く
なるほど長くなるという性質から求められた凹みの深さ
と該透過波の周波数の遅延時間との間で相関関係を示す
式に基づき、前記送信波に対応した透過波の周波数の遅
延時間から計算して凹みの深さを推定するようにしたも
のであり、送信波の所定の周波数に対応した遅延時間を
求めれて所定の式を計算することにより、被検体の表層
部の凹みの深さを容易に高精度に推定できるという効果
を有する。Further, in the method for estimating a surface damage according to a fourth aspect of the present invention, a transmission wave having a predetermined frequency is used, and a delay time of a transmitted wave having a frequency corresponding to the transmission wave increases as the depth of the dent increases. Based on the equation showing the correlation between the depth of the dent determined from the property of becoming longer and the delay time of the frequency of the transmitted wave, the dent is calculated from the delay time of the frequency of the transmitted wave corresponding to the transmission wave. The depth of the dent of the surface layer of the subject can be easily increased by calculating the delay time corresponding to the predetermined frequency of the transmission wave and calculating the predetermined formula. This has the effect that estimation can be performed with high accuracy.
【００３５】このように、本発明は傷の方向に関りなく
表層傷の深さを自動的に精度良く推定できるので、被検
体の表層部の傷をオンラインで検出してその傷の深さを
容易に高精度に推定できるようになり、表面波を用いた
表層部探傷の信頼性向上と適用範囲拡大に極めて効果を
奏するものである。As described above, according to the present invention, the depth of the surface layer can be automatically and accurately estimated regardless of the direction of the wound. Can be easily and accurately estimated, and this is extremely effective in improving the reliability of surface layer flaw detection using surface waves and expanding the applicable range.
【図１】本発明の表層傷の推定方法を実施する実施の形
態１の装置の構成を示すブロック図である。FIG. 1 is a block diagram showing a configuration of an apparatus according to a first embodiment for implementing a method for estimating a surface damage according to the present invention.
【図２】同装置を用いて測定した開口傷及び非開口傷に
対する透過波の減衰量の測定結果を示す図である。FIG. 2 is a diagram showing the results of measuring the amount of attenuation of a transmitted wave with respect to an opening flaw and a non-aperture flaw measured using the same apparatus.
【図３】同装置を用いて測定した開口傷に対する透過波
の減衰量の比と傷の深さ／波長との関係を示すグラフで
ある。FIG. 3 is a graph showing the relationship between the ratio of the attenuation of a transmitted wave to an open wound measured using the same apparatus and the depth / wavelength of the wound.
【図４】同装置を用いて測定した非開口傷に対する透過
波の減衰量の比と傷の深さ／波長との関係を示すグラフ
である。FIG. 4 is a graph showing the relationship between the ratio of attenuation of a transmitted wave to a non-open wound measured using the same apparatus and the depth / wavelength of the wound.
【図５】本発明の実施形態１の表層傷の推定方法を示す
フローチャートである。FIG. 5 is a flowchart illustrating a method for estimating a surface damage according to the first embodiment of the present invention.
【図６】同装置を用いて測定した凹みの傷に対する透過
波の遅延時間の測定結果を示す図である。FIG. 6 is a diagram showing a measurement result of a delay time of a transmitted wave with respect to a dent scratch measured using the same device.
【図７】同装置を用いて測定した凹みの傷に対する透過
波の遅延時間の波形図である。FIG. 7 is a waveform diagram of a delay time of a transmitted wave with respect to a dent scar measured using the same device.
【図８】本発明の表層傷の推定方法を実施する実施の形
態２の装置の構成を示すブロック図である。FIG. 8 is a block diagram showing a configuration of an apparatus according to a second embodiment for implementing the method for estimating a surface wound according to the present invention.
【図９】同装置を用いて測定した開口傷及び非開口傷に
対する透過波の時間一周波数分布を示す図である。FIG. 9 is a diagram showing a time-frequency distribution of a transmitted wave with respect to an opening flaw and a non-opening flaw measured using the same apparatus.
【図１０】同装置を用いて測定した凹みの傷に対する透
過波の時間−周波数分布を示す図である。FIG. 10 is a diagram showing a time-frequency distribution of a transmitted wave with respect to a dent wound measured using the same device.
【図１１】同装置を用いて測定した凹みの傷に対する透
過波の遅延時間の波形図である。FIG. 11 is a waveform diagram of a delay time of a transmitted wave with respect to a dent flaw measured using the same device.
１ バースト波送信器 ２ 送信用表面波探触子 ３ 被検体 ４ 傷 ５ 受信用表面波探触子 ６ 受信器 DESCRIPTION OF SYMBOLS 1 Burst wave transmitter 2 Transmission surface wave probe 3 Subject 4 Scratches 5 Reception surface wave probe 6 Receiver
Claims (4)
を探傷し、表層傷の種類を推定する表層傷の推定法にお
いて、 所定の周波数の表面波となる送信波を用い、前記送信波
に対応した周波数の透過波の減衰量を所定のしきい値と
比較し、該減衰量が所定のしきい値を越えるときは開口
傷と推定し、該減衰量が所定のしきい値を越えないとき
は非開口傷と推定することを特徴とする表層傷の推定
法。In a method for estimating a surface flaw of a subject using a transmitted wave of a surface wave and estimating a type of the surface flaw, a transmission wave serving as a surface wave having a predetermined frequency is used. The attenuation of the transmitted wave of the frequency corresponding to the transmission wave is compared with a predetermined threshold, and when the attenuation exceeds a predetermined threshold, it is estimated that the aperture is flawed. A method for estimating a superficial wound, which is characterized by estimating a non-opening wound when the value does not exceed the limit.
を探傷し、開口の表層傷の深さを推定する表層傷の推定
法において、 異なる周波数を含む送信波を用い、前記送信波の各周波
数に対応したそれぞれの透過波が、開口傷が浅い場合は
高い周波数側のみが大きく減衰し、開口傷が浅くなるに
つれて低い周波数まで減衰するという性質から求められ
た開口傷の深さと各周波数に対応したそれぞれの透過波
の減衰量との間で相関関係を示す式に基づき、前記送信
波の各周波数に対応したそれぞれの透過波の減衰量から
計算して開口傷の深さを推定することを特徴とする表層
傷の推定法。2. A method for estimating a surface flaw of a subject using a transmitted wave of a surface wave and estimating a depth of the surface flaw of an opening, wherein the transmission using a transmission wave having a different frequency is performed. Each transmitted wave corresponding to each frequency of the wave, when the opening flaw is shallow, only the high frequency side is greatly attenuated, and as the opening flaw becomes shallow, it attenuates to a lower frequency and the depth of the opening flaw is calculated from the property Based on the equation showing the correlation between the attenuation of each transmitted wave corresponding to each frequency, based on the attenuation of each transmitted wave corresponding to each frequency of the transmission wave, calculate the depth of the opening flaw A method for estimating a superficial wound characterized by estimating.
を探傷し、非開口の表層傷の深さを推定する表層傷の推
定法において、 異なる周波数を含む送信波を用い、前記送信波の各周波
数に対応したそれぞれの透過波が、深さ位置が浅いほど
高い周波数の減衰は小さく、深くなるほど低い周波数の
減衰も小さくなるという性質から求められた非開口傷の
深さと、各周波数に対応したそれぞれの透過波の減衰量
との間で相関関係を示す式に基づき、前記送信波の各周
波数に対応したそれぞれの透過波の減衰量から計算して
非開口傷の深さを推定することを特徴とする表層傷の推
定法。3. A method for estimating a surface flaw of a subject using a transmitted wave of a surface wave and estimating a depth of a non-apertured surface flaw, wherein a transmission wave including a different frequency is used. Each transmitted wave corresponding to each frequency of the transmission wave, the depth of the non-aperture flaw determined from the property that the attenuation of the high frequency is small as the depth position is shallow, and the attenuation of the low frequency is small as the depth position is deep, Based on the expression showing the correlation between the attenuation of each transmitted wave corresponding to the frequency, the depth of the non-aperture flaw is calculated from the attenuation of each transmitted wave corresponding to each frequency of the transmission wave. A method for estimating a superficial wound characterized by estimating.
を探傷し、凹みの表層傷の深さを推定する表層傷の推定
法において、 所定の周波数の送信波を用い、前記送信波に対応した周
波数の透過波の遅延時間が凹みの深さが深くなるほど長
くなるという性質から求められた凹みの深さと所定の周
波数の送信波に対応した透過波の周波数の遅延時間との
間で相関関係を示す式に基づき、前記送信波に対応した
透過波の周波数の遅延時間から計算して凹みの深さを推
定することを特徴とする表層傷の推定法。4. A surface flaw estimating method for detecting a surface flaw of a subject using a transmitted wave of a surface wave and estimating a depth of a concave surface flaw, wherein the transmission is performed using a transmission wave of a predetermined frequency. Between the depth of the dent determined from the property that the delay time of the transmitted wave at the frequency corresponding to the wave increases as the depth of the dent increases, and the delay time of the frequency of the transmitted wave corresponding to the transmission wave at the predetermined frequency And estimating the depth of the dent by calculating from the delay time of the frequency of the transmitted wave corresponding to the transmission wave, based on the equation indicating the correlation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9014213A JPH10213573A (en) | 1997-01-28 | 1997-01-28 | Estimating method for surface layer damage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9014213A JPH10213573A (en) | 1997-01-28 | 1997-01-28 | Estimating method for surface layer damage |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10213573A true JPH10213573A (en) | 1998-08-11 |
Family
ID=11854827
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9014213A Pending JPH10213573A (en) | 1997-01-28 | 1997-01-28 | Estimating method for surface layer damage |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10213573A (en) |
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|---|---|---|---|---|
| JP2007017300A (en) * | 2005-07-07 | 2007-01-25 | Toshiba Corp | Surface inspection device and surface inspection method |
| JP2007017298A (en) * | 2005-07-07 | 2007-01-25 | Toshiba Corp | Surface inspecting method and surface inspection device |
| JP2009244079A (en) * | 2008-03-31 | 2009-10-22 | Tokyo Electric Power Co Inc:The | Ultrasonic flaw detector for turbine blade implanted part and flaw detection method using the same |
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| EP2148195A1 (en) | 2005-07-07 | 2010-01-27 | Kabushiki Kaisha Toshiba | Laser-based apparatus for ultrasonic flaw detection |
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| JP2014013187A (en) * | 2012-07-04 | 2014-01-23 | Mitsubishi Electric Corp | Array flaw detection device and method |
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1997
- 1997-01-28 JP JP9014213A patent/JPH10213573A/en active Pending
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|---|---|---|---|---|
| EP2159575A2 (en) | 2005-07-07 | 2010-03-03 | Kabushiki Kaisha Toshiba | Laser-based apparatus for ultrasonic flaw detection |
| EP2157426A1 (en) | 2005-07-07 | 2010-02-24 | Kabushiki Kaisha Toshiba | Maintenance apparatus using laser generated ultrasound |
| US8248595B2 (en) | 2005-07-07 | 2012-08-21 | Kabushiki Kaisha Toshiba | Laser-based maintenance apparatus for inspecting flaws based on a generated surface wave |
| JP4746365B2 (en) * | 2005-07-07 | 2011-08-10 | 株式会社東芝 | Surface inspection method |
| EP2148195A1 (en) | 2005-07-07 | 2010-01-27 | Kabushiki Kaisha Toshiba | Laser-based apparatus for ultrasonic flaw detection |
| EP2148196A1 (en) | 2005-07-07 | 2010-01-27 | Kabushiki Kaisha Toshiba | Laser-based apparatus for ultrasonic flaw detection |
| JP2007017298A (en) * | 2005-07-07 | 2007-01-25 | Toshiba Corp | Surface inspecting method and surface inspection device |
| EP2278324A1 (en) | 2005-07-07 | 2011-01-26 | Kabushiki Kaisha Toshiba | Ultrasonic laser-based maintenance apparatus |
| EP2148197A1 (en) | 2005-07-07 | 2010-01-27 | Kabushiki Kaisha Toshiba | Ultrasonic laser-based maintenance apparatus |
| JP2007017300A (en) * | 2005-07-07 | 2007-01-25 | Toshiba Corp | Surface inspection device and surface inspection method |
| JP2009244079A (en) * | 2008-03-31 | 2009-10-22 | Tokyo Electric Power Co Inc:The | Ultrasonic flaw detector for turbine blade implanted part and flaw detection method using the same |
| JP2009276095A (en) * | 2008-05-12 | 2009-11-26 | Jfe Civil Engineering & Construction Corp | Non-destructive flaw detecting method and non-destructive flaw detector |
| JP2010038908A (en) * | 2008-07-10 | 2010-02-18 | Shimizu Corp | Apparatus and method for measuring depth of crack in concrete surface by ultrasonic wave |
| JP2014013187A (en) * | 2012-07-04 | 2014-01-23 | Mitsubishi Electric Corp | Array flaw detection device and method |
| JP2021124373A (en) * | 2020-02-05 | 2021-08-30 | 株式会社東芝 | Laser ultrasonic measurement device and method for measuring laser ultrasonic |
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