JP6159926B2

JP6159926B2 - Simultaneous identification method of transmission point and physical properties (degradation status) in elastic wave tomography performed on measurement object of inhomogeneous physical properties

Info

Publication number: JP6159926B2
Application number: JP2013048061A
Authority: JP
Inventors: 昌平桃木; 小林　義和; 義和小林; 塩谷　智基; 智基塩谷
Original assignee: Kyoto University; Tobishima Corp
Current assignee: Kyoto University; Tobishima Corp
Priority date: 2013-03-11
Filing date: 2013-03-11
Publication date: 2017-07-12
Anticipated expiration: 2033-03-11
Also published as: JP2014174040A

Description

本発明は、物性が均質な構造体などの測定対象物について行われる弾性波を使用したトモグラフィではなく、不均質な物性からなる構造物などの測定対象物について行われる弾性波トモグラフィにおける、例えばＡＥ音などの発信点および物性分布状況（劣化状況）の同時特定方法に関するものである。
The present invention is not a tomography using elastic waves performed on a measurement object such as a structure having a uniform physical property, but an elastic wave tomography performed on a measurement object such as a structure having inhomogeneous physical properties. For example, the present invention relates to a method for simultaneously specifying a transmission point such as an AE sound and a physical property distribution state (deterioration state).

トモグラフィとは、測定対象物における検査領域内の多数の、あるいは多方向の走査線間における「計測走時」と、解析モデルから算出される「理論走時」との「走時残差」を許容誤差内に収束させるように、解析モデルの要素パラメータ、例えば弾性波の伝搬速度を補正し、前記検査領域を補正された各要素の速度の分布図で表す手法を指標するものである。 Tomography refers to the “runtime residual” between the “measurement travel time” between multiple or multi-directional scan lines in the inspection area of the measurement object and the “theoretical travel time” calculated from the analysis model. The parameter of the analysis model, for example, the propagation velocity of the elastic wave is corrected so as to converge within the permissible error, and the method of representing the inspection area with the corrected velocity distribution diagram of each element is indicated.

前記の速度の分布図によって測定対象物内部の欠陥等の位置や経年劣化などの程度を、例えば通常の伝搬速度より遅い低速度の領域として示すことが出来るものとなる。
そして、前記速度の分布図解析は、例えば、複数の弾性波波形観測センサによって検出された弾性波の波形を分析することにより行われている。 The velocity distribution map can indicate the position of defects inside the measurement object and the degree of aging, for example, as a low-speed region that is slower than the normal propagation speed.
The velocity distribution map analysis is performed, for example, by analyzing the elastic wave waveforms detected by a plurality of elastic wave waveform observation sensors.

ここで、当該非破壊検査システムの検査手法の一手段である、いわゆる走査線間の計測走時の取得は、鋼球等で入力された弾性波の発信波形および受信波形を、それぞれ設置したセンサ（発信用センサ、受信用センサ）で収録し、読み取られる初動時刻の差から算出し、解析するものとしていた（特開２０１１−１９１２０２号公報参照）。 Here, acquisition of the measurement running time between so-called scanning lines, which is one means of the inspection method of the nondestructive inspection system, is a sensor in which an elastic wave transmission waveform and a reception waveform input by a steel ball or the like are respectively installed. It was calculated and analyzed from the difference in initial movement time recorded and read by (transmitting sensor, receiving sensor) (refer to JP 2011-191202 A).

ところで、前記弾性波の発信手段としては、前述したように、例えば弾性波発信用器具となる金属製ハンマーなどで打撃するなどの手段が必ず必要とされていると共に、検査の精度を高めるためには、測定対象物における検査領域内の極力多くの箇所を発信箇所として打撃せねばならず、当該発信箇所付近に配置する弾性波波形観測用センサ（発信用センサ）も打撃箇所数に伴って多数個必要とされ、そしてこの多数の発信用センサを所定の複数箇所に予め多数設置しておかなければなければならなかった。 By the way, as described above, as means for transmitting the elastic wave, for example, means such as hitting with a metal hammer as an elastic wave transmitting instrument is always required, and in order to increase the accuracy of the inspection. Requires hitting as many places as possible in the inspection area of the object to be measured as a transmission point, and there are a large number of elastic wave waveform observation sensors (transmitting sensors) arranged in the vicinity of the transmission point. A large number of sensors for transmission are required and a large number of sensors for transmission must be set in advance at a plurality of predetermined locations.

前記の金属製ハンマーで、例えば高速道路の床面などコンクリート測定対象物所定箇所に打撃を加える等、強制的な形での発信手段を講じるためには、さらに、常設の足場を構築して、その足場を利用し、測定対象物所定箇所に作業者が出向き、その上で前記高速道路の床面などを打撃するなどの発信手段を講じなければならない。 In order to take a sending means in a forced form, such as hitting a concrete measurement target object such as a floor surface of an expressway with the metal hammer, for example, a permanent scaffold is constructed, Using the scaffold, an operator must go to a predetermined location of the measurement object and then take a transmission means such as hitting the floor of the expressway.

すると作業自体も時間と手間がかかるほか、費用コストも高額となり、特に前述の高架橋等の高所作業を伴う場合では、作業者の安全面も含めて従来のトモグラフィを利用した測定対象物の非破壊検査システムは適用しがたいものであった。 The work itself is time consuming and labor intensive, and the cost is high.In particular, when working at high places such as the viaduct mentioned above, the measurement object using conventional tomography, including the safety aspects of the operator, is required. Non-destructive inspection systems were difficult to apply.

すなわち、上記従来のトモグラフィを利用した測定対象物の非破壊検査システムでは、例えば、金属製ハンマーでの打撃や鋼球等での打撃により、測定対象物の非破壊検査の検査領域に能動的に弾性波を入力（発信）することが必須であり、ゆえに、観測時にも作業者が検査領域に近づかなければならないため、足場等設備が必須となる。 That is, in the above-described conventional non-destructive inspection system for a measurement object using tomography, for example, by using a metal hammer or a steel ball, it is possible to actively apply to a non-destructive inspection area of the measurement object. It is indispensable to input (transmit) elastic waves to the surface. Therefore, since the operator must approach the inspection area even during observation, facilities such as a scaffold are indispensable.

そして、これは、前記測定対象物の非破壊検査の検査領域を経時的にモニタリングする場合にも同様で、その都度検査領域に近づかなければならないことになる。また、前述したように、発信波形を収録するための発信用センサの設置も必須であり、発信点数および発信位置は予め設置されたセンサ位置となるため、走査線数も限られてしまうとの課題があったのである。 This also applies to the case where the inspection area of the non-destructive inspection of the measurement object is monitored over time, and the inspection area must be approached each time. In addition, as described above, it is essential to install a transmission sensor for recording a transmission waveform, and since the number of transmission points and the transmission position are the sensor positions installed in advance, the number of scanning lines is limited. There was a problem.

さらに、上記従来のトモグラフィを利用した測定対象物の非破壊検査システムは、前述のとおり走時残差を許容誤差内に収束させる手法を主な検査手法として採用しており、当該手法によれば、発振箇所数及び受信箇所数をなるべく多数設置し、また受信箇所数は発信箇所数とほぼ同数設けることが精度よく劣化等の状況を把握できるもとされていた。 Furthermore, the above-described conventional non-destructive inspection system for measuring objects using tomography employs a technique for converging the running time residual within an allowable error as described above as a main inspection technique. For example, the number of oscillation points and the number of reception points are set as many as possible, and the number of reception points is set to be almost the same as the number of transmission points.

このため、受信用センサも発信用センサと同様、多数設置することが求められ、これにより設置コストの大幅上昇は勿論のこと、調査の準備作業に多大な労力と手間を要していたとの課題があった。 For this reason, it is required to install a large number of receiving sensors as well as the transmitting sensors, which not only greatly increases the installation cost but also requires a lot of labor and labor for the preparation work for the survey. was there.

これらの課題を解決すべく、発明者らは鋭意創案を重ね、前記測定対象物において発する音を複数設置された弾性波波形計測センサによって受信し、これにより特定された受信時刻と受信位置によって、発信時刻と発信位置を推定する数式を用いて演算し、前記発した音の推定発信時刻と推定発信位置を求め、そして、この求められた推定発信時刻と推定発信位置の値を用いて前記トモグラフィ解析を行う手法を発明するに至ったのである。 In order to solve these problems, the inventors repeated diligent ingenuity, received sound generated by the measurement object by a plurality of elastic wave waveform measurement sensors, and the reception time and reception position specified thereby, A calculation is performed using a mathematical expression for estimating a transmission time and a transmission position, an estimated transmission time and an estimated transmission position of the emitted sound are obtained, and the estimated transmission time and the estimated transmission position are used to calculate the tomo The inventors have invented a technique for performing graphic analysis.

しかしながら、前記の手法は、前記測定対象物の物性があくまでも均質に構成されていることが前提とされており、該測定対象物の物性が均質であることにより測定対象物のいかなる箇所にあってもほぼ同様の速度で弾性波が伝播するとのことが前述した解析手法の前提条件とされているのである。 However, the above-described technique is based on the premise that the physical properties of the measurement object are configured to be homogeneous, and the physical properties of the measurement object are uniform, so that the measurement object can be located anywhere. The precondition of the above-described analysis method is that the elastic wave propagates at substantially the same speed.

しかるに、コンクリート測定対象物などの場合、その物性が均質に構成されていない場合が多く存在する。例えば前記測定対象物の構成材料などに不均質部材が含まれていたり、あるいは測定対象物に使用した材料に経年変化などによる劣化が不均一に生じたり、さらに測定対象物内の一部箇所に空洞やひび割れが生じたりした場合などである。 However, in the case of a concrete measurement object or the like, there are many cases where the physical properties are not configured uniformly. For example, the constituent material of the measurement object includes a heterogeneous member, or the material used for the measurement object is unevenly deteriorated due to secular change or the like. This is the case when cavities or cracks occur.

このような場合においては、前述した測定対象物において発する音を複数設置された弾性波波形計測センサによって受信し、これにより特定された受信時刻と受信位置によって、発信時刻と発信位置を推定する数式を用いて演算し、前記発した音の推定発信時刻と推定発信位置を求め、そして、この求められた推定発信時刻と推定発信位置の値を用いて前記トモグラフィ解析を行う手法を採用することが出来ないとの課題が存在していた。 In such a case, the mathematical expression for receiving the sound emitted from the measurement object described above by a plurality of installed elastic wave waveform measurement sensors and estimating the transmission time and transmission position based on the reception time and reception position specified thereby. To calculate the estimated transmission time and estimated transmission position of the emitted sound, and to adopt the method of performing the tomography analysis using the calculated estimated transmission time and estimated transmission position values There was a problem that it was not possible.

なぜなら、前記の様に測定対象物の物性が不均質の場合、前記の手法では、発信時刻と発信位置を推定する数式を用いて演算を行っても、正確な推定発信時刻と推定発信位置が求められないとの課題があるからである。
This is because, when the physical properties of the measurement object are inhomogeneous as described above, the above-described method can obtain an accurate estimated transmission time and estimated transmission position even if calculation is performed using a mathematical expression that estimates the transmission time and transmission position. This is because there is a problem that is not required.

特開２０１１−１９１２０２号公報JP 2011-191202 A

かくして、本発明は前記従来の課題を解決するために創案されたものであり、たとえ前記測定対象物の物性が不均質であったとしても、該不均質物性測定対象物の正確なトモグラフィ解析を行うのに必要な、例えばＡＥ音などの「発信位置」あるいは「発信時刻」の特定が正確に行え、さらには測定対象物の物性分布状況（劣化状況）の特定さえも同時に行えることとなる不均質物性の測定対象物につき行われる弾性波トモグラフィにおける発信点・物性状況（劣化状況）同時特定方法を提供することを目的とするものである。
Thus, the present invention was devised to solve the above-described conventional problems, and even if the physical property of the measurement object is inhomogeneous, an accurate tomographic analysis of the inhomogeneous physical property measurement object is performed. For example, it is possible to accurately specify “sending position” or “sending time” such as AE sound, and even specify the physical property distribution state (deterioration state) of the measurement object at the same time. It is an object of the present invention to provide a method for simultaneously specifying a transmission point and a physical property state (deterioration state) in elastic wave tomography performed for a measurement object of inhomogeneous physical properties.

本発明は、
測定対象物において発せられた音の発信時刻、発信位置及び前記音の受信時刻、受信位置を用い、発信波形計測センサから受信波形計測センサ間の実際の弾性波伝播時間を算出し、
前記発信波形計測センサから受信波形計測センサ間に複数の分岐点を設けた解析モデルを形成し、該解析モデルから前記発信波形計測センサから受信波形計測センサ間の理論値としての弾性波伝播時間を算出すると共に、求められた理論値としての弾性波伝播時間を前記実際の弾性波伝播時間に近づける演算を行って、前記分岐点で分岐された分岐線内領域の弾性波伝播速度の速度分布を形成し、形成された速度分布により破壊検査を行うトモグラフィ解析を利用した測定対象物の非破壊検査方法であって、
立体状をなす測定対象物内に多面体状検査領域を設け、該多面体状検査領域の頂点を前記測定対象物表面上に形成すると共に、形成された４点以上の頂点に受信波形計測センサを設置し、設置した受信波形計測センサにより前記測定対象物において発する音を前記発信波形計測センサを用いることなく受信し、該受信波形計測センサにより特定された受信時刻と受信位置及び前記音が複数の受信波形計測センサに到達する際に設定された同一伝播速度の値とにより発信時刻と発信位置を推定する数式を用いて演算し、前記発した音の推定発信時刻と推定発信位置を求めてなり、
前記求められた推定発信時刻と推定発信位置の値を用いて前記トモグラフィ解析を行う測定対象物の非破壊検査方法において、
前記測定対象物が不均質な物性から構成されてなるときは、前記音が複数の受信波形計測センサに到達する際に設定された同一伝播速度の値ではなく、前記検査領域あるいは検査領域を適宜分割した小領域で、不均質な物性に応じた伝播速度の値を数式で用いて算出すると共に、算出された異なる各伝播速度の値を用いて前記発した音の推定発信時刻と推定発信位置を求める演算を行ってなり、
前記演算を、前記複数の受信波形計測センサにより特定された受信時刻とほぼ同等になるまで繰り返し行い、前記検査領域あるいは検査領域を適宜分割した小領域内での前記伝播速度を求め、求めた前記伝播速度の違いにより前記測定対象物の前記検査領域あるいは検査領域を適宜分割した小領域ごとの前記伝播速度の速度分布を求め、求められた前記測定対象物の前記速度分布により測定対象物の構成材料に不均質物質が含まれていた場合やひび割れ、劣化の不均質箇所を反映した前記音の真の発信位置および発信時刻が特定できると共に、前記検査領域あるいは検査領域を適宜分割した小領域内での前記測定対象物の劣化状況が特定できる、
ことを特徴とし、
または、
測定対象物において発せられた音の発信時刻、発信位置及び前記音の受信時刻、受信位置を用い、発信波形計測センサから受信波形計測センサ間の実際の弾性波伝播時間を算出し、
前記発信波形計測センサから受信波形計測センサ間に複数の分岐点を設けた解析モデルを形成し、該解析モデルから前記発信波形計測センサから受信波形計測センサ間の理論値としての弾性波伝播時間を算出すると共に、求められた理論値としての弾性波伝播時間を前記実際の弾性波伝播時間に近づける演算を行って、前記分岐点で分岐された分岐線内領域の弾性波伝播速度の速度分布を形成し、形成された速度分布により破壊検査を行うトモグラフィ解析を利用した測定対象物の非破壊検査方法であって、
前記発信波形計測センサを用いることなく、前記測定対象物において発する音を、測定対象物の表面上に多角形を構成するよう検査領域を設け、少なくとも前記多角形の頂点となる位置に複数設置された受信波形計測センサにより受信し、該受信波形計測センサにより特定された受信時刻と受信位置及び前記音が複数の受信波形計測センサに到達する際に設定された同一伝播速度の値とにより発信時刻と発信位置を推定する数式を用いて演算し、前記発した音の推定発信時刻と推定発信位置を求めてなり、
前記求められた推定発信時刻と推定発信位置の値を用いて前記トモグラフィ解析を行う測定対象物の非破壊検査方法において、
前記測定対象物が不均質な物性から構成されてなるときは、前記音が複数の受信波形計測センサに到達する際に設定された同一伝播速度の値ではなく、前記検査領域あるいは検査領域を適宜分割した小領域で、不均質な物性に応じた伝播速度の値を数式で用いて算出すると共に、算出された異なる各伝播速度の値を用いて前記発した音の推定発信時刻と推定発信位置を求める演算を行ってなり、
前記演算を、前記複数の受信波形計測センサにより特定された受信時刻とほぼ同等になるまで繰り返し行い、、前記検査領域あるいは検査領域を適宜分割した小領域内での前記伝播速度を求め、求めた前記伝播速度の違いにより前記測定対象物の前記検査領域あるいは検査領域を適宜分割した小領域ごとの前記伝播速度の速度分布を求め、求められた前記測定対象物の前記速度分布により測定対象物の構成材料に不均質物質が含まれていた場合やひび割れ、劣化の不均質箇所を反映した前記音の真の発信位置および発信時刻が特定できると共に、前記検査領域あるいは検査領域を適宜分割した小領域内での前記測定対象物の劣化状況が特定できる、
ことを特徴とし、
または、
前記測定対象物において発する音は、外力負荷により自然的に発生する微小音たるＡＥ音である、
ことを特徴とし、
または、
前記不均質な物性からなる測定対象物は、交通荷重により自然的に発生するＡＥ音を発信情報として利用できる橋梁床板や高速道路床板である、
ことを特徴とするものである。
The present invention
Using the transmission time of the sound emitted from the measurement object, the transmission position and the reception time of the sound, the reception position, the actual elastic wave propagation time between the reception waveform measurement sensor and the transmission waveform measurement sensor is calculated,
An analysis model in which a plurality of branch points are provided between the transmission waveform measurement sensor and the reception waveform measurement sensor is formed, and an elastic wave propagation time as a theoretical value between the transmission waveform measurement sensor and the reception waveform measurement sensor is determined from the analysis model. And calculating the velocity distribution of the elastic wave propagation velocity in the branch line area branched at the branch point by calculating the elastic wave propagation time as the calculated theoretical value close to the actual elastic wave propagation time. A non-destructive inspection method for an object to be measured using tomographic analysis for forming and performing a destructive inspection with the formed velocity distribution,
A polyhedral inspection region is provided in a three-dimensional measurement object, and apexes of the polyhedral inspection region are formed on the surface of the measurement object, and reception waveform measurement sensors are installed at four or more formed vertices. The received waveform measurement sensor receives the sound emitted from the measurement object without using the transmission waveform measurement sensor, and the reception time and reception position specified by the reception waveform measurement sensor and the sound are received in plural. Calculated by using a mathematical expression that estimates the transmission time and transmission position based on the value of the same propagation velocity set when reaching the waveform measurement sensor, to determine the estimated transmission time and estimated transmission position of the emitted sound,
In the non-destructive inspection method of the measurement object that performs the tomography analysis using the obtained estimated transmission time and the estimated transmission position value,
When the measurement object is composed of inhomogeneous physical properties, the inspection region or the inspection region is appropriately set instead of the value of the same propagation velocity set when the sound reaches a plurality of received waveform measurement sensors. In the divided small areas, the propagation speed value corresponding to the heterogeneous physical properties is calculated using mathematical formulas, and the estimated transmission time and estimated transmission position of the sound emitted using the calculated different propagation speed values. To calculate
The calculation is repeated until the reception times specified by the plurality of received waveform measurement sensors are substantially equal, and the propagation speed in a small area obtained by appropriately dividing the inspection area or the inspection area is obtained, and the obtained Determine the velocity distribution of the propagation velocity for each of the inspection areas of the measurement object or the small areas obtained by appropriately dividing the inspection area according to the difference in propagation velocity, and configure the measurement object based on the obtained velocity distribution of the measurement object When the material contains an inhomogeneous substance, the true transmission position and the transmission time of the sound reflecting the cracked or deteriorated inhomogeneous part can be specified, and the inspection area or the small area obtained by dividing the inspection area as appropriate The degradation status of the measurement object at can be specified,
It is characterized by
Or
Using the transmission time of the sound emitted from the measurement object, the transmission position and the reception time of the sound, the reception position, the actual elastic wave propagation time between the reception waveform measurement sensor and the transmission waveform measurement sensor is calculated,
An analysis model in which a plurality of branch points are provided between the transmission waveform measurement sensor and the reception waveform measurement sensor is formed, and an elastic wave propagation time as a theoretical value between the transmission waveform measurement sensor and the reception waveform measurement sensor is determined from the analysis model. And calculating the velocity distribution of the elastic wave propagation velocity in the branch line area branched at the branch point by calculating the elastic wave propagation time as the calculated theoretical value close to the actual elastic wave propagation time. A non-destructive inspection method for an object to be measured using tomographic analysis for forming and performing a destructive inspection with the formed velocity distribution,
Without using the transmission waveform measurement sensor, the sound emitted from the measurement object is provided with an inspection area so as to form a polygon on the surface of the measurement object, and a plurality of sounds are installed at positions that are at least the vertexes of the polygon. Received by the received waveform measurement sensor, and the transmission time based on the reception time specified by the received waveform measurement sensor, the reception position, and the value of the same propagation velocity set when the sound reaches a plurality of received waveform measurement sensors. And calculating using the mathematical formula for estimating the transmission position, and determining the estimated transmission time and estimated transmission position of the emitted sound,
In the non-destructive inspection method of the measurement object that performs the tomography analysis using the obtained estimated transmission time and the estimated transmission position value,
When the measurement object is composed of inhomogeneous physical properties, the inspection region or the inspection region is appropriately set instead of the value of the same propagation velocity set when the sound reaches a plurality of received waveform measurement sensors. In the divided small areas, the propagation speed value corresponding to the heterogeneous physical properties is calculated using mathematical formulas, and the estimated transmission time and estimated transmission position of the sound emitted using the calculated different propagation speed values. To calculate
The calculation is repeated until the reception times specified by the plurality of reception waveform measurement sensors are substantially equal to each other , and the propagation speed in the inspection region or a small region obtained by appropriately dividing the inspection region is obtained and obtained. The velocity distribution of the propagation velocity is obtained for each of the inspection regions of the measurement object or the small areas obtained by appropriately dividing the inspection region according to the difference in the propagation velocity, and the measurement object is measured by the velocity distribution of the obtained measurement objects. When the component material contains an inhomogeneous material, cracks, and the sound's true transmission position and transmission time reflecting the inhomogeneous portion of the deterioration can be specified, and the inspection region or a small region obtained by dividing the inspection region as appropriate The deterioration status of the measurement object can be specified in
It is characterized by
Or
The sound emitted from the measurement object is an AE sound that is a minute sound that is naturally generated by an external force load.
It is characterized by
Or
The measurement object consisting of the heterogeneous physical properties is a bridge floor board or a highway floor board that can use AE sound that naturally occurs due to traffic load as transmission information.
It is characterized by this.

本発明によれば、たとえ前記測定対象物の物性が不均質であったとしても、該不均質物性測定対象物の正確なトモグラフィ解析を行うのに必要な、例えばＡＥ音などの「発信位置」あるいは「発信時刻」の特定が正確に行え、さらには測定対象物の物性分布状況（劣化状況）の特定さえも同時に行えることとなる不均質物性の測定対象物につき行われる弾性波トモグラフィにおける発信点・物性状況（劣化状況）同時特定方法を提供出来るとの優れた効果を奏する。
According to the present invention, even if the physical property of the object to be measured is inhomogeneous, the “transmission position” such as an AE sound necessary for performing an accurate tomographic analysis of the object to be measured inhomogeneous property is provided. ”Or“ transmission time ”can be accurately specified, and even the physical property distribution status (deterioration status) of the measurement object can be specified at the same time in the elastic wave tomography performed for the measurement object of heterogeneous physical properties It has an excellent effect that it can provide a method for simultaneously specifying the transmission point and physical property status (degradation status).

本発明におけるける第１実施例の構成を説明する説明図である。It is explanatory drawing explaining the structure of 1st Example in this invention. 本発明における第２実施例の構成を説明する説明図（１）である。It is explanatory drawing (1) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（２）である。It is explanatory drawing (2) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（３）である。It is explanatory drawing (3) explaining the structure of 2nd Example in this invention. 本発明に関連する従来手法の構成を説明する説明図（１）である。It is explanatory drawing (1) explaining the structure of the conventional method relevant to this invention. 本発明に関連する従来手法の構成を説明する説明図（２）である。It is explanatory drawing (2) explaining the structure of the conventional method relevant to this invention. 本発明に関連する従来手法の構成を説明する説明図（３）である。It is explanatory drawing (3) explaining the structure of the conventional method relevant to this invention. 本発明に関連する従来手法の構成を説明する説明図（４）である。It is explanatory drawing (4) explaining the structure of the conventional method relevant to this invention. 本発明における第２実施例の構成を説明する説明図（４）である。It is explanatory drawing (4) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（５）である。It is explanatory drawing (5) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（６）である。It is explanatory drawing (6) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（７）である。It is explanatory drawing (7) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（８）である。It is explanatory drawing (8) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（９）である。It is explanatory drawing (9) explaining the structure of 2nd Example in this invention. 本発明に関連する従来手法の構成を説明する説明図（５）である。It is explanatory drawing (5) explaining the structure of the conventional method relevant to this invention. 本発明に関連する従来手法の構成を説明する説明図（６）である。It is explanatory drawing (6) explaining the structure of the conventional method relevant to this invention. 本発明に関連する従来手法の構成を説明する説明図（７）である。It is explanatory drawing (7) explaining the structure of the conventional method relevant to this invention. 本発明における第２実施例の構成を説明する説明図（１０）である。It is explanatory drawing (10) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（１１）である。It is explanatory drawing (11) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（１２）である。It is explanatory drawing (12) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（１３）である。It is explanatory drawing (13) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（１４）である。It is explanatory drawing (14) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（１５）である。It is explanatory drawing (15) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（１６）である。It is explanatory drawing (16) explaining the structure of 2nd Example in this invention. 本発明における第２実施例の構成を説明する説明図（１７）である。It is explanatory drawing (17) explaining the structure of 2nd Example in this invention.

以下、本発明を図に示す実施例に基づいて説明する。 Hereinafter, the present invention will be described based on embodiments shown in the drawings.

（第１実施例）
図１に、本発明の第１実施例を示す。ここで、図１は立方体をなす測定対象物１につき本発明を適用したもので、立方体をなす測定対象物１の内部に多面体状の検査領域２０を形成した例を示すものである。 (First embodiment)
FIG. 1 shows a first embodiment of the present invention. Here, FIG. 1 shows an example in which the present invention is applied to a measuring object 1 that forms a cube, and a polyhedral inspection region 20 is formed inside the measuring object 1 that forms a cube.

この場合、多面体状の検査領域２０における４点以上の前記測定対象物１の表面に形成される頂点に受信波形計測センサ３・・・を設置し、該受信波形計測センサ３・・・により前記測定対象物１において発する音を発信波形計測センサ２を用いることなく受信できるものとしている。 In this case, the reception waveform measurement sensors 3... Are installed at the apexes formed on the surface of the measurement object 1 at four or more points in the polyhedral inspection region 20, and the reception waveform measurement sensors 3. The sound emitted from the measurement object 1 can be received without using the transmission waveform measurement sensor 2.

図１は、本実施例の基本的構成を示すものであり、立体の測定対象物１に対して、前述の如く、その表面上に複数の頂点を有する多面体状の検査領域２０を想定し、その頂点の中から４点以上の頂点に対して受信波形計測センサ３・・・を設けてＡＥ波等の受信情報を計測できるように構成している。 FIG. 1 shows a basic configuration of the present embodiment. As described above, for a three-dimensional measurement object 1, a polyhedral inspection region 20 having a plurality of vertices on the surface is assumed. Reception waveform measurement sensors 3 are provided for four or more vertices from among the vertices so that reception information such as AE waves can be measured.

ここでは、多面体状の検査領域２０を測定対象物１の上側表面に位置する４点と下側表面に位置する４点とで構成される四角柱（直方体）と想定し、上側表面の４点のみに受信波形計測センサ３・・・を設置した場合を示している。
なお、多面体状の検査領域２０の形状は、その他の形状である多角柱をはじめ、多角錐であっても、オベリスクのようなものであってもよい。 Here, assuming that the polyhedron-shaped inspection region 20 is a quadrangular prism (cuboid) composed of four points located on the upper surface of the measurement object 1 and four points located on the lower surface, four points on the upper surface. Only when the received waveform measuring sensors 3... Are installed.
The shape of the polyhedral inspection region 20 may be a polygonal pyramid, which is another shape, a polygonal pyramid, or an obelisk.

また、受信波形計測センサ３を設置する箇所については、設置することが可能ならば測定対象物１の下側表面に設けてもよい。その場合には、上側表面と下側表面とで合計４点以上となるように、受信波形計測センサ３・・・を設置することになる。 In addition, the place where the reception waveform measurement sensor 3 is installed may be provided on the lower surface of the measurement object 1 if it can be installed. In that case, the received waveform measurement sensors 3... Are installed so that the total number of points on the upper surface and the lower surface is 4 or more.

そして、所定の期間、供用状態(通常の使用状態)にある測定対象物１が発するＡＥ波を計測することにより、受信波形計測センサ３の設置位置におけるＡＥ波の受信時刻や受信波形等の受信情報を取得する。 Then, by measuring the AE wave emitted from the measuring object 1 in the in-service state (normal use state) for a predetermined period, the reception time of the AE wave, the reception waveform and the like at the installation position of the reception waveform measurement sensor 3 are received. Get information.

ＡＥ波の発信源の位置や測定対象物の物性分布状況の特定については、まず、測定対象物１全体の伝播速度を一般的な物性諸元（例えば、測定対象物がコンクリート構造物である場合は、健全な状態で約４，０００ｍ／秒）と仮定して、各受信波形計測センサ３・・・で取得された受信情報に基づき、ＡＥ波の受信時刻を最もよく説明できる、すなわち、各受信情報に対して最小誤差となるように、暫定発信源の位置と暫定発信時刻とを逆解析によって求める。 Regarding the identification of the position of the AE wave source and the physical property distribution of the measurement object, first, the propagation speed of the entire measurement object 1 is determined based on general physical properties (for example, the measurement object is a concrete structure). Is about 4,000 m / sec in a healthy state), and can best explain the reception time of the AE wave based on the reception information acquired by each reception waveform measurement sensor 3. The position of the provisional transmission source and the provisional transmission time are obtained by inverse analysis so that the received information has a minimum error.

次に、多面体状の検査領域２０内を中間節点２２・・・を設けて適宜小領域に分割したうえで、各受信情報に対する前記最小誤差をさらに小さくするように、当該小領域ごとの伝播速度を補正した後、前記暫定発信源から各受信波形計測センサ３の位置までのＡＥ波の伝播経路（走査線）を複数設定して、前記暫定発信時刻に対する各受信センサ位置での第一次理論受信時刻を算出する。 Next, the polyhedral inspection region 20 is divided into small regions as appropriate by providing intermediate nodes 22... And the propagation speed for each small region is further reduced so that the minimum error for each received information is further reduced. After correcting the above, a plurality of AE wave propagation paths (scanning lines) from the provisional transmission source to the position of each reception waveform measurement sensor 3 are set, and the first-order theory at each reception sensor position with respect to the provisional transmission time. Calculate the reception time.

なお、伝播経路を複数設定する理由は、測定対象物１内に劣化等による欠陥個所では伝播速度が小さくなるので、当該欠陥個所を通る受信波形計測センサ３までの伝播経路に対して算出した理論受信時刻よりも、欠陥個所を迂回するように設定した伝播経路に対する理論受信時刻の方が早い可能性に配慮するためである。つまり、実際に計測されるＡＥ波の受信時刻は、測定対象物１内の状態に関するあらゆる可能性に対して最短理論走時となるように算出するものであり、解析プログラム上で考慮しておけばよい。この時点では、第一次理論受信時刻と前記暫定発信時刻との差が、理論走時となる。 The reason why a plurality of propagation paths are set is that the propagation speed is small at a defective part due to deterioration or the like in the measurement object 1, and the theory calculated for the propagation path to the received waveform measuring sensor 3 passing through the defective part. This is to consider the possibility that the theoretical reception time for the propagation path set to bypass the defective part is earlier than the reception time. In other words, the reception time of the actually measured AE wave is calculated so as to be the shortest theoretical travel time for all possibilities related to the state in the measurement object 1 and should be considered in the analysis program. That's fine. At this time, the difference between the first theoretical reception time and the provisional transmission time is the theoretical travel time.

以下、各受信波形計測センサ３の位置における受信時刻と暫定発信時刻との差を計測走時に相当する値として、理論走時８と計測走時７の相当値との差異を許容誤差内に収まるように、前記逆解析と理論受信時刻の算出を繰り返し行うことで、前記小領域の物性を補正しながら、発信源と測定対象物１の物性分布状況を同時特定することにより、測定対象物１の内部の劣化状況等を把握することができる。 Hereinafter, the difference between the reception time and the provisional transmission time at the position of each received waveform measurement sensor 3 is defined as a value corresponding to the measurement travel time, and the difference between the theoretical travel time 8 and the equivalent value of the measurement travel time 7 is within an allowable error. As described above, by repeatedly performing the inverse analysis and the calculation of the theoretical reception time, the physical property distribution status of the transmission source and the measurement object 1 is simultaneously specified while correcting the physical property of the small area, thereby the measurement object 1 It is possible to grasp the deterioration state of the inside of the machine.

すなわち、本発明では、発信手段は勿論のこと、発信情報を用いることなく、立体形状をなす測定対象物１に対して、必要最低限の箇所における受信情報の取得のみで、解析上の工夫によって、測定対象物１の劣化状況等を非破壊で検査できるようにしたことに大きな特徴がある。 In other words, in the present invention, not only the transmission means but also the transmission information is used, and the measurement object 1 having a three-dimensional shape can be obtained only by obtaining the reception information at the minimum necessary position, and by means of analysis. The main feature is that the deterioration state of the measurement object 1 can be inspected nondestructively.

したがって、本発明によって、検査のための足場構築が不要となり、さらに、検査員による高所作業も不要で、安全で合理的な非破壊検査が可能になったことに加えて、今まで測定対象物１の表面上に多数のセンサを設置しなければ、劣化状況等の把握が困難だった厚みの大きいコンクリート構造物であっても、内部の劣化の有無等を把握することが可能になった。 Therefore, according to the present invention, it is not necessary to construct a scaffold for inspection, and it is not necessary to work at a high place by an inspector. If many sensors are not installed on the surface of the object 1, it is now possible to determine the presence or absence of internal deterioration, even for thick concrete structures where it was difficult to determine the deterioration status. .

以上は、立体をなす多面体状の検査領域２０を想定した実施例であるが、具体的な解析をはじめ、本発明における計測手法の詳細については、本発明に含まれるいわゆる板状の測定対象物１に適用される平面（二次元）解析の場合と同様なので、後述する本発明に係る第２実施例である板状の測定対象物１に適用する平面（二次元）解析の場合で詳細に説明することにする。 The above is an example assuming a polyhedral inspection region 20 having a three-dimensional shape. For details of the measurement technique in the present invention including specific analysis, a so-called plate-shaped measurement object included in the present invention is described above. Since this is the same as the case of the plane (two-dimensional) analysis applied to 1, the case of the plane (two-dimensional) analysis applied to the plate-like measuring object 1 according to the second embodiment of the present invention to be described later is described in detail. I will explain.

（第２実施例）
図１５から理解されるように、従来、弾性波トモグラフィを利用した測定対象物１の非破壊検査システムにあっては、通常、測定対象物１の既知位置に設置された発信波形計測センサ２及び受信波形計測センサ３と、前記発信波形計測センサ２の近傍位置で測定対象物１の表面を打撃して弾性波を発信させ、前記発信波形計測センサ２及び受信波形計測センサ３に受信させる弾性波発信用器具４とを必要とする。 (Second embodiment)
As can be understood from FIG. 15, conventionally, in a nondestructive inspection system for a measurement object 1 using elastic wave tomography, a transmission waveform measurement sensor 2 usually installed at a known position of the measurement object 1. And the received waveform measuring sensor 3 and the elasticity of causing the transmitted waveform measuring sensor 2 and the received waveform measuring sensor 3 to receive an elastic wave by hitting the surface of the measurement object 1 at a position near the transmitted waveform measuring sensor 2. A wave transmitting device 4 is required.

そして、前記発信波形計測センサ２では、発信した弾性波の波形を受信して、当該弾性波の発信時刻と発信位置を特定するものであった。従って、弾性波発信器具４による打撃は、発信波形計測センサ２の近傍位置であることが必要とされていたのである。
また、前記受信波形計測センサ３では前記弾性波の波形を受信し、その受信時刻と受信位置とを特定するものである。 The transmission waveform measuring sensor 2 receives the waveform of the transmitted elastic wave and specifies the transmission time and transmission position of the elastic wave. Therefore, the impact by the elastic wave transmission device 4 is required to be in the vicinity of the transmission waveform measurement sensor 2.
The reception waveform measuring sensor 3 receives the waveform of the elastic wave and specifies the reception time and reception position.

そして、これら特定された発信時刻、発信位置、受信時刻、受信位置の値を用いて演算し、前記発信波形計測センサ２から受信波形計測センサ３までの距離における実際の弾性波伝播時間、すなわち、計測走時７を算出するものとしていた（図１５、図１６、図１７参照）。 And it calculates using the value of these specified transmission time, transmission position, reception time, reception position, the actual elastic wave propagation time at the distance from the transmission waveform measurement sensor 2 to the reception waveform measurement sensor 3, that is, The measured running time 7 was calculated (see FIGS. 15, 16, and 17).

一方、図１８に示す様に発信波形計測センサ２から受信波形計測センサ３間に複数の分岐点６・・・を設けた解析モデル５を形成し、該解析モデル５より前記発信波形計測センサ２から受信波形計測センサ３の間の理論値としての弾性波伝播時間、すなわち、理論走時８を算出するものとしている（図１９参照）。 On the other hand, as shown in FIG. 18, an analysis model 5 having a plurality of branch points 6... Is formed between the transmission waveform measurement sensor 2 and the reception waveform measurement sensor 3, and the transmission waveform measurement sensor 2 is formed from the analysis model 5. To the elastic wave propagation time as a theoretical value between the received waveform measuring sensors 3, that is, the theoretical travel time 8 is calculated (see FIG. 19).

そして、求められた理論値としての弾性波伝播時間、すなわち、理論走時８と、前記実際の弾性波伝播時間、すなわち、計測走時７とが等しくなるよう演算を行うのである。 Then, the calculation is performed so that the elastic wave propagation time as the calculated theoretical value, that is, the theoretical travel time 8 is equal to the actual elastic wave propagation time, that is, the measured travel time 7.

この際、前記分岐点６・・・を分岐線１１で囲み、分岐線１１・・・で囲まれたそれぞれの分岐線内領域９・・・でのそれぞれの速度分布を算出すると共に、算出されたそれぞれの分岐線内領域９・・・での速度分布により、例えば、速度が極端に遅い箇所の分岐線内領域９に速度が遅くなる原因、すなわち欠陥が存在するなどの破壊検査が行えるものとなっていたのである（図１９、図２０参照）。 At this time, the branch points 6... Are surrounded by the branch lines 11, and the respective velocity distributions in the respective branch line inner regions 9. In addition, the velocity distribution in each branch line region 9... Enables, for example, destructive inspection such as the cause of the slow speed in the branch line region 9 where the speed is extremely slow, that is, the presence of a defect. (See FIGS. 19 and 20).

しかしながら、前述したように、高速道路の床面などについて、従来のトモグラフィ解析を利用した測定対象物１の非破壊検査システムの適用は困難であり、本発明者らは、前記高速道路の床面などについて、作業者の弾性波発信行為を必要とせず、例えば高速道路を走行する車両などにより生じた音（アコースティックエミッション音：ＡＥ音）などを発信情報として捉え、該音（ＡＥ音）の発生時刻及び発生位置を算出して、従来の発信時刻及び発信位置に代替する検査システムを創案するに至ったのである。 However, as described above, it is difficult to apply the nondestructive inspection system for the measuring object 1 using the conventional tomographic analysis to the floor surface of the expressway. For example, a sound generated by a vehicle traveling on a highway (acoustic emission sound: AE sound) or the like is regarded as transmission information without requiring an operator to transmit an elastic wave, and the sound (AE sound) The inventor has come up with an inspection system that calculates the generation time and the generation position and substitutes for the conventional transmission time and transmission position.

しかして、図２４は、その一実施例を示したものであり、測定対象物１、例えば高速道路の床面の裏面に、複数の受信波形計測センサ３・・・のみ設置してある例（ここでは４つの受信波形計測センサ３を設置）を示している。そして、高速道路を走行する車両により、ＡＥ音１０が生じたとする例である。 FIG. 24 shows an example of this, and an example in which only a plurality of received waveform measuring sensors 3... Are installed on the measurement object 1, for example, the back surface of the expressway floor ( Here, four reception waveform measurement sensors 3 are installed). In this example, the AE sound 10 is generated by the vehicle traveling on the highway.

なお、４つの受信波形計測センサ３・・・で囲まれた領域、すなわち検査領域２０内には複数の分岐点６・・・が設けられ、これら分岐点６・・・を繋ぐ分岐線１１が形成されて、それぞれの分岐線内領域９・・・が確定される。 A plurality of branch points 6... Are provided in a region surrounded by the four received waveform measurement sensors 3..., That is, the inspection region 20, and a branch line 11 connecting these branch points 6. As a result, each branch line area 9... Is determined.

この例においては、前記ＡＥ音１０が生じても、その発生時刻及び発生位置は特定できない。しかしながら、図２４において、例えば、４つの受信波形計測センサ３・・・により、前記ＡＥ音１０の受信時刻及び受信位置は特定できる。よって、特定されたＡＥ音１０の受信時刻及び受信位置からＡＥ音１０の発生時刻（発信時刻）及び発生位置（発信位置）を推定する数式を用い、該式を用いて演算を行い、前記ＡＥ音１０の発生時刻（発信時刻）及び発生位置（発信位置）が推定出来るのである。 In this example, even when the AE sound 10 is generated, the generation time and generation position cannot be specified. However, in FIG. 24, for example, the reception time and reception position of the AE sound 10 can be specified by the four reception waveform measurement sensors 3. Therefore, using the mathematical expression for estimating the generation time (transmission time) and the generation position (transmission position) of the AE sound 10 from the reception time and reception position of the specified AE sound 10, the calculation is performed using the formula, and the AE The generation time (transmission time) and generation position (transmission position) of the sound 10 can be estimated.

しかして、この数式としては、たとえば、地震の震源決定法などの数式が用いられる（図２１乃至図２３参照）。なお、特定されたＡＥ音１０の受信時刻及び受信位置から、発信情報となるＡＥ音１０の発生時刻（発信時刻）及び発生位置（発信位置）を推定出来る数式であれば、前記地震の震源決定法の数式使用に限定されるものではない。 Thus, for example, mathematical formulas such as an earthquake source determination method are used (see FIGS. 21 to 23). In addition, if it is a numerical formula which can estimate the generation | occurrence | production time (transmission time) and generation | occurrence | production position (transmission position) of AE sound 10 used as transmission information from the reception time and reception position of the specified AE sound 10, the epicenter determination of the said earthquake will be carried out. It is not limited to the use of math formulas.

図２１乃至図２３から理解されるように、いわゆる受信時刻を用いた非線形最小２乗法による震源決定法によって、図２４に示す発信情報となるＡＥ音１０の発信時刻及び発信座標が算出、推定されるものとなる。
すなわち、図２３に示すｄｔ^（ｍ）がＡＥ音１０の発信時刻であり、（ｘｓ^（ｍ）、ｙｓ^（ｍ））が発信座標となる。 As understood from FIG. 21 to FIG. 23, the transmission time and transmission coordinates of the AE sound 10 that is the transmission information shown in FIG. Will be.
That is, dt ^(m) shown in FIG. 23 is a transmission time of the AE sound 10, and (xs ^(m) , ys ^(m) ) is a transmission coordinate.

そして、ＡＥ音１０の発信時刻であるｄｔ^（ｍ）、発信位置を示す発信座標（ｘｓ^（ｍ）、ｙｓ^（ｍ））を用い、図１７に示す、計測走時７に相当する値を推算し、図１９に示す、理論走時８を逆算によって算定するのである。 Then, dt ^(m) which is the transmission time of the AE sound 10 and transmission coordinates (xs ^(m) and ys ^(m) ) indicating the transmission position are used to estimate a value corresponding to the measured traveling time 7 shown in FIG. The theoretical running time 8 shown in FIG. 19 is calculated by back calculation.

すなわち、これら特定された発信時刻ｄｔ^（ｍ）、発信位置（ｘｓ^（ｍ）、ｙｓ^（ｍ））、受信時刻、受信位置の値を用いて演算し、前記ＡＥ音１０の発信位置から受信波形計測センサ３までの距離における実際の弾性波伝播時間、すなわち、計測走時７に相当する値を推算する（図１５、図１６、図１７参照）。 That is, calculation is performed using these specified transmission time dt ^(m) , transmission position (xs ^(m) , ys ^(m) ), reception time, and reception position values, and the received waveform from the transmission position of the AE sound 10 is calculated. The actual elastic wave propagation time at the distance to the measurement sensor 3, that is, a value corresponding to the measurement travel time 7 is estimated (see FIGS. 15, 16, and 17).

一方、ＡＥ音１０（図１９では発信点）から受信波形計測センサ３間に複数の分岐点６・・・を設けた解析モデル５を形成し、該解析モデルから前記ＡＥ音１０（図１９の発信点）から受信波形計測センサ３の間の理論値としての弾性波伝播時間、すなわち、理論走時８を算出する（図１９参照）。 On the other hand, an analysis model 5 in which a plurality of branch points 6... Are provided between the AE sound 10 (the transmission point in FIG. 19) and the received waveform measurement sensor 3 is formed, and the AE sound 10 (of FIG. 19) is formed from the analysis model. An elastic wave propagation time as a theoretical value between the transmission point) and the received waveform measuring sensor 3, that is, a theoretical travel time 8 is calculated (see FIG. 19).

そして、求められた理論値としての弾性波伝播時間、すなわち、理論走時８を前記実際の弾性波伝播時間、すなわち、計測走時７に相当する値を収束させる演算を行って、前記分岐点６・・・を分岐線１１・・・で繋ぎ、それらの分岐線１１・・・で分岐されたそれぞれの分岐線内領域９・・・のそれぞれの速度を算出し、もって前記それぞれの分岐線内領域９・・・における速度分布を形成し、形成された速度分布により、例えば、速度が極端に遅い箇所の分岐線内領域９に速度が遅くなる原因、すなわち欠陥が存在するなどの破壊検査が行えるのである（図２０参照）。 Then, an elastic wave propagation time as the calculated theoretical value, that is, a theoretical travel time 8 is calculated to converge the actual elastic wave propagation time, that is, a value corresponding to the measured travel time 7, and the branch point 6... Are connected by branch lines 11... And the respective velocities in the branch line regions 9... Branched by these branch lines 11. A speed distribution is formed in the inner region 9..., And the cause of the speed becoming slow in the branch line inner region 9 at a place where the speed is extremely slow, for example, a defect exists due to the formed speed distribution. (See FIG. 20).

しかしながら、前記の例はあくまで、測定対象物１の物性が均質である場合を想定したものであり、コンクリート構造物などの測定対象物１の物性が不均質のものとして構成されている場合には、前述した手法によって正確な発信時刻や発信位置が特定できるものではない。なぜなら、前述の数式で用いられる弾性波の伝播速度については、測定対象物1の物性が均質で。検査領域20では全て同じ伝播速度であることが前提になっているからである。 However, the above example is supposed only when the physical properties of the measurement object 1 are homogeneous, and when the physical properties of the measurement object 1 such as a concrete structure are configured as heterogeneous. The accurate transmission time and transmission position cannot be specified by the above-described method. This is because the physical properties of the object 1 to be measured are uniform with respect to the propagation velocity of the elastic wave used in the above formula. This is because all the inspection areas 20 are premised on the same propagation velocity.

そこで、本件発明者らはさらに新しい発明を創案し、たとえ測定対象物１の物性が不均質な場合、すなわち、例えば前記測定対象物１の構成材料などに不均質部材が多く含まれていたり、あるいは測定対象物１に使用した材料に経年変化などによる劣化が不均一に生じたり、さらに測定対象物分岐線内領域９・・・を１内の一部箇所に空洞やひび割れが生じたりした場合であっても、例えばＡＥ音１０の発生点、換言すれば、発信点、すなわち発信時刻や発信位置を正確に特定することが出来、もって、測定対象物１の物性が不均質な場合であっても弾性波によるトモグラフィによる非破壊検査システムが正確に、かつ確実に運用できる方法を発明するに至ったのである。 Therefore, the present inventors have created a new invention, even if the physical property of the measurement object 1 is inhomogeneous, that is, for example, the constituent material of the measurement object 1 contains many heterogeneous members, Alternatively, when the material used for the measurement object 1 is deteriorated unevenly due to aging, etc., or the measurement object branch line region 9... However, for example, the generation point of the AE sound 10, in other words, the transmission point, that is, the transmission time and the transmission position can be specified accurately, and thus the physical property of the measurement object 1 is inhomogeneous. However, the inventors have invented a method that can operate the nondestructive inspection system by tomography using elastic waves accurately and reliably.

ここで、本発明の手法を従来法と比較して説明する。
図２から理解されるように、（１）４つの受信波形計測センサ３・・・で囲まれた対象となる領域、すなわち検査領域２０内に、複数の分岐点６・・・を設け、これら分岐点６・・・を繋ぐ分岐線１１を形成して、それぞれの分岐線内領域９・・・を確定する。すなわち、検査領域20を分岐線内領域９・・・（ここでは４つの分岐線内領域９）、すなわち小領域のセルに分割するのである。 Here, the method of the present invention will be described in comparison with the conventional method.
As can be understood from FIG. 2, (1) a plurality of branch points 6... Are provided in a target region surrounded by four received waveform measurement sensors 3. A branch line 11 that connects the branch points 6... Is formed, and each branch line inner region 9. That is, the inspection area 20 is divided into branch line inner areas 9... (Here, four branch line inner areas 9), that is, small area cells.

そして、各セル、すなわち分岐線内領域９・・・は均質の物性で構成されていると仮定し、それぞれのセル、すなわち分岐線内領域９・・・に弾性波が伝播する伝播速度を同じ速度として与えておく。 Assuming that each cell, that is, the branch line region 9 is composed of homogeneous physical properties, the propagation velocity of the elastic wave propagating to each cell, that is, the branch line region 9 is the same. Give it as a speed.

複数の分岐点６・・・は、いわゆるセルの構成節点になり、検査領域２０内において、発信点の候補となる点であるが、（２）さらに前記４つの分岐線内領域９内に、複数の中間節点２２・・・を分布させておく。 The plurality of branch points 6 are so-called cell constituent nodes, and are points that are candidates for transmission points in the inspection region 20, (2) Further, in the four branch line in-regions 9, A plurality of intermediate nodes 22... Are distributed.

そして、（３）受信点２４から全節点６・・・、２２・・・までの走査線における伝播時間を、４つの分岐線内領域９・・・（各４つのセル）に与えられた伝播速度と、４つの分岐線内領域９・・・（各４つのセル）を横切る走査線長を基に算出していく。 (3) Propagation time on the scanning lines from the receiving point 24 to all the nodes 6... 22... Is propagated to the four branch line regions 9. The calculation is based on the speed and the length of the scanning line that crosses the four branch line regions 9... (Four cells each).

ついで、（４）各受信時刻より伝播時間を引くことで全節点６・・・、２２・・・における推定発信時刻（受信点数分）を求めるのである。
そして、（５）前記求められた推定発信時刻の分散値、すなわち誤差の量が最小となる節点６・・・、２２・・・を発信点と暫定する。これを暫定発信点と仮に名付ける。 Next, (4) by subtracting the propagation time from each reception time, the estimated transmission time (for the number of reception points) at all nodes 6.
Then, (5) the obtained dispersion value of the estimated transmission time, that is, nodes 6... , 22. This is tentatively named as a temporary transmission point.

ついで、図３から理解されるように、（６）前記の暫定発信点から各受信点までの走査線における伝播時間を算出する（この時、発信時刻は推定発信時刻の平均値を用いる）。 Next, as understood from FIG. 3, (6) the propagation time in the scanning line from the provisional transmission point to each reception point is calculated (at this time, the average value of the estimated transmission time is used as the transmission time).

さらに、（７）発信時刻と受信時刻から求められる伝播時間（計測走時）と、解析モデル５上で４つの分岐線内領域９・・・（４つのセル）に与えられた伝播速度および４つの分岐線内領域９・・・（４つのセル）を横切る走査線長から求められる伝播時間（理論走時）が等しくなるように、４つの分岐線内領域９・・・（各４つのセル）に与えられた伝播速度を補正していく。 Furthermore, (7) the propagation time (measurement travel time) obtained from the transmission time and the reception time, the propagation speed given to the four branch line regions 9 (four cells) on the analysis model 5 and 4 Four branch line regions 9... (Four cells each) so that the propagation times (theoretical travel times) obtained from the scanning line lengths across the two branch line regions 9. ) Will be corrected.

そして、（８）補正された４つの分岐線内領域９・・・（４つのセル）の伝播速度を基に再度受信点から全節点までの走査線における伝播時間および推定発信時刻を求めていく。 Then, (8) the propagation time and the estimated transmission time on the scanning line from the reception point to all the nodes are obtained again based on the corrected propagation speed of the four branch line regions 9... (4 cells). .

さらに、前述した（３）乃至（８）の動作を繰り返し行うことにより、局所的な不均質性が、４つの分岐線内領域９・・・（各４つのセル）で補正される伝播速度によって反映されながら、正しい発信点が特定されていくのである。 Further, by repeating the operations (3) to (8) described above, the local inhomogeneity is corrected by the propagation velocity corrected in the four branch line regions 9 (four cells each). The correct transmission point is identified while being reflected.

以上のように、本発明は、測定対象物1の物性の不均質性を反映した発信点特定（同定）手法であり、また、調査・対象となる領域をセル分割したモデルを使用した発信点特定（同定）手法であって、『理論走時（解析モデルによる）』が、『計測走時（暫定発信点と推定発信時刻による）』と等しくなるように各セルの伝播速度を補正し、セル内の伝播速度が補正されることで、測定対象物1の物性の不均質性を反映した発信点特定（同定）が可能となるのである。さらに、この特定（同定）精度は、中間節点２２・・・の分布密度を高くすることにより任意に調整でき、特定精度の向上が出来るものとなっている。 As described above, the present invention is a transmission point identification (identification) technique that reflects the heterogeneity of the physical properties of the measurement object 1, and the transmission point using a model in which the area to be investigated / target is divided into cells. It is a specific (identification) method, and the propagation speed of each cell is corrected so that “theoretical travel time (according to the analysis model)” is equal to “measured travel time (according to the provisional transmission point and estimated transmission time)” By correcting the propagation velocity in the cell, it is possible to identify (identify) the transmission point that reflects the heterogeneity of the physical properties of the measurement object 1. Further, the identification (identification) accuracy can be arbitrarily adjusted by increasing the distribution density of the intermediate nodes 22... And the identification accuracy can be improved.

ここで、さらに図を参照して説明する。
まず、図５乃至図８は、本発明に関連する従来手法による発信点位置同定を説明する説明図であり、潜在する（目視でわからない）箇所も含め物性が均質な測定対象物１と仮定した場合のモデルでの解析となっている。 Here, further description will be made with reference to the drawings.
First, FIG. 5 to FIG. 8 are explanatory diagrams for explaining transmission point position identification by a conventional method related to the present invention, and it is assumed that the measurement object 1 has a uniform physical property including a latent (not visible) portion. Analysis with case model.

図６に示す様に、実際に得られた４つの受信時刻を基に、全ての候補点（図５に示すように×印で示すＮｏ．１乃至Ｎｏ．４９候補点）に対する伝播時間および推定発信時刻を求めていく。 As shown in FIG. 6, based on the four reception times actually obtained, propagation times and estimations for all candidate points (No. 1 to No. 49 candidate points indicated by X as shown in FIG. 5). We will ask for outgoing time.

そして、図７に示す様に、発信された1つの信号に対して、４つのセンサで受信していることから、各センサの受信時刻を基に算出された４つの推定発信時刻が等しい（または分散が最小となる）候補点が発信点として特定（同定）される。 As shown in FIG. 7, since four sensors receive one transmitted signal, the four estimated transmission times calculated based on the reception time of each sensor are equal (or Candidate points with the smallest variance are identified (identified) as transmission points.

なお、ここで、分散とは、平均に対してどの程度離れているか、すなわちバラツキの程度を表す統計量であり、誤差の量とも言える。この例の場合、次式で求められる。
４つの推定発信時刻の分散：

Here, the variance is a statistic indicating how far away from the average, that is, the degree of variation, and can be said to be the amount of error. In this example, it is obtained by the following equation.
Dispersion of four estimated transmission times:

その結果、
候補点[Ｎｏ．31]が発信点とされる（図８参照）。
（ただし、

は４つの推定発信時刻の平均値）
ここで、候補点[Ｎｏ．25]は真の正しい発信点であるが、該候補点[Ｎｏ．25]における分散：8.437E-09 になっているからである。 as a result,
Candidate points [No. 31] is the transmission point (see FIG. 8).
(However,

Is the average of four estimated transmission times)
Here, the candidate point [No. 25] is a true correct transmission point, but the candidate point [No. This is because the variance in 25] is 8.437E-09.

しかして、図８に示す様に、測定対象物1の物性を均質として考え、検査領域２０内の伝播速度は全て一定：４、０００m/秒としてあるモデルのため、分散、すなわち誤差の量が最小となる候補点は、真の正しい発信点とはならないのである。 Therefore, as shown in FIG. 8, since the physical property of the measurement object 1 is considered to be uniform and the propagation velocity in the inspection region 20 is all constant: 4,000 m / sec, the dispersion, that is, the amount of error is The smallest candidate point is not the true correct origin.

すなわち、前述したように、真の発信点である候補点[Ｎｏ．25]における分散値は8.437E-09 であるのに対し、候補点[Ｎｏ．31]における分散値は4.079E-09 となっており、従来手法では、真の発信点である候補点[Ｎｏ．25]より分散値、すなわち誤差の量が候補点[Ｎｏ．31]が少なく、その結果、候補点[Ｎｏ．31]が発信点と決定されてしまうのである。 That is, as described above, the candidate point [No. 25] is 8.437E-09, while the candidate point [No. 31] is 4.079E-09. In the conventional method, the candidate point [No. 25], the variance value, that is, the amount of error is the candidate point [No. 31], and as a result, candidate points [No. 31] is determined as the transmission point.

このことは、測定対象物1内に、測定対象物の構成材料などに不均質部材が含まれており、伝播速度が遅くなる箇所があっても従来の均質モデルには反映されず、『時間が掛かる＝他のセンサよりも遠かった』と見なされることによるものである。
そこで、本発明では、測定対象物１の物性がたとえ不均質であったとしても、正確に発信点を特定（同定）出来るものとした。 This is because the measurement object 1 contains non-homogeneous materials in the constituent material of the measurement object, and even if there is a place where the propagation speed is slow, it is not reflected in the conventional homogeneous model. It is because it is regarded as “It was farther than other sensors”.
Therefore, in the present invention, even if the physical properties of the measurement object 1 are inhomogeneous, the transmission point can be accurately specified (identified).

本発明による測定対象物１の物性がたとえ不均質であったとしても、正確に発信点を特定（同定）出来る発信点位置同定につき、図９乃至図１４を参照して説明する。 With reference to FIG. 9 to FIG. 14, transmission point position identification that can specify (identify) a transmission point accurately even if the physical properties of the measurement object 1 according to the present invention are inhomogeneous will be described.

まず、４つの小領域（セル）に分割した解析モデル５を用いるのは従来と同様である。そして、各４つのセルには、それぞれ伝播速度を与える。図９では初期値として全てに４、０００m/秒の伝搬速度を与えている。 First, the analysis model 5 divided into four small regions (cells) is used as in the conventional case. A propagation speed is given to each of the four cells. In FIG. 9, a propagation velocity of 4,000 m / sec is given to all as initial values.

次に、図１０に示すように、各セルの伝播速度とセル内を横切る長さから候補点までの伝播時間を算出する。これも従来法と同様である。 Next, as shown in FIG. 10, the propagation time from the propagation speed of each cell and the length across the cell to the candidate point is calculated. This is also the same as the conventional method.

さらに、図１１に示す様に、この場合において、４つのセルに与えられた初期値が全て４、０００m/秒（均質モデルと同様）であるため、分散値、すなわち誤差の量が最小となるのは従来手法と同じ候補点[Ｎｏ．31]となってしまっている。 Further, as shown in FIG. 11, in this case, since the initial values given to the four cells are all 4,000 m / sec (similar to the homogeneous model), the dispersion value, that is, the amount of error is minimized. Is the same candidate point [No. 31].

しかし、本発明では、図１２に示す様に、推定発信時刻の平均、すなわち前述の候補点[Ｎｏ．31]での推定発信時刻の平均を暫定発信時刻としてまず、暫定発信点を仮に決めておく。 However, in the present invention, as shown in FIG. 12, the average of the estimated transmission time, that is, the candidate point [No. 31] First, the provisional transmission point is provisionally determined with the average of the estimated transmission time in [31] as the provisional transmission time.

そして、図１２に示す４つの各受信点における受信時刻を算出し、実際に得られた受信時刻との誤差を求めていくのである。 Then, the reception time at each of the four reception points shown in FIG. 12 is calculated, and an error from the actually obtained reception time is obtained.

そして、図１３に示す様に、解析モデル５における暫定発信点を用いた４つの受信点での受信時刻が、実際に得られた受信時刻と等しくなるように、分岐線内領域９（セル）に与えた伝播速度を補正し、補正モデルで再度推定発信時刻を求めていくのである。 Then, as shown in FIG. 13, the branch line area 9 (cell) is set so that the reception times at the four reception points using the temporary transmission points in the analysis model 5 are equal to the actually obtained reception times. The propagation speed given to is corrected, and the estimated transmission time is obtained again by the correction model.

これにより、図１３から理解されるように、ひび割れや劣化が潜在し、物性が不均一とされる箇所、すなわち経路２の箇所では、伝播速度が当初の４、０００ｍ／秒から２、５００ｍ／秒及び１、５００ｍ／秒と補正されるのである。 Thus, as understood from FIG. 13, the propagation speed is increased from the initial 4,000 m / second to 2,500 m / second in the portion where the cracks and deterioration are latent and the physical properties are not uniform, that is, the route 2 portion. Seconds and 1,500 m / s are corrected.

そして、図１４に示す様に、経路２において伝播速度が補正された補正モデルで、再度計算を行い、その結果、候補点[Ｎｏ．25]における分散値、補正の量が1．00E-10との値となり、全候補点での最小の分散値、すなわち補正の量とされ、もって、候補点[Ｎｏ．25]が真の発信点と認定できるのである。 Then, as shown in FIG. 14, the calculation is performed again with the correction model in which the propagation velocity is corrected in the path 2, and as a result, the candidate point [No. 25] is a value of 1.00E-10, which is the minimum variance value at all candidate points, that is, the amount of correction, and thus the candidate point [No. 25] can be recognized as a true transmission point.

しかして、物性が不均質な測定対象物につき、前記の様に真の発信点が確定できた後は、従来と同様に、該真の発信点における発信時刻及び発信位置並びに受信時刻及び受信位置の値を用いる、すなわち、これら特定された発信時刻ｄｔ^（ｍ）、発信位置（ｘｓ^（ｍ）、ｙｓ^（ｍ））、受信時刻、受信位置の値を用いて演算し、前記真の発信位置（候補点[Ｎｏ．25]）から受信波形計測センサ３までの距離における実際の弾性波伝播時間、すなわち、計測走時７を算出する（再度図１５、図１６、図１７参照）。 Thus, after the true transmission point can be determined as described above for a measurement object with non-homogeneous physical properties, the transmission time and transmission position, reception time and reception position at the true transmission point are the same as in the past. That is, the true transmission position is calculated using the specified transmission time dt ^(m) , transmission position (xs ^(m) , ys ^(m) ), reception time, and reception position values. The actual elastic wave propagation time at the distance from the (candidate point [No. 25]) to the received waveform measurement sensor 3, that is, the measurement travel time 7 is calculated (see FIGS. 15, 16, and 17 again).

一方、真の発信点（候補点[Ｎｏ．25]：図１９では発信点）から受信波形計測センサ３間に複数の分岐点６・・・を設けた解析モデル５を形成し、該解析モデルから前記真の発信点（候補点[Ｎｏ．25]：図１９では発信点）から受信波形計測センサ３の間の理論値としての弾性波伝播時間、すなわち、理論走時８を算出する（図１９参照）。 On the other hand, an analysis model 5 is formed in which a plurality of branch points 6... Are provided between the true transmission point (candidate point [No. 25]: transmission point in FIG. 19) and the received waveform measurement sensor 3. From the true transmission point (candidate point [No. 25]: transmission point in FIG. 19) to the received wave measurement sensor 3, the elastic wave propagation time, that is, the theoretical travel time 8 is calculated (see FIG. 19).

そして、求められた理論値としての弾性波伝播時間、すなわち、理論走時８を前記実際の弾性波伝播時間、すなわち、計測走時７に近づける演算を行って、前記分岐点６・・・を分岐線１１・・・で繋ぎ、それらの分岐線１１・・・で分岐されたそれぞれの分岐線内領域９・・・のそれぞれの速度を算出し、もって前記測定対象物1の物性がたとえ不均質であったとしても前記それぞれの分岐線内領域９・・・における速度分布が正確に形成でき、該正確に形成された速度分布により、例えば、速度が極端に遅い箇所の分岐線内領域９に速度が遅くなる原因、すなわち欠陥が存在するなどの破壊検査が行えるのである（図２０参照）。 Then, a calculation is performed to bring the elastic wave propagation time as the calculated theoretical value, that is, the theoretical travel time 8 close to the actual elastic wave propagation time, that is, the measurement travel time 7, and the branch point 6. The speed of each of the branch line regions 9... Connected by the branch lines 11... And branched by the branch lines 11. Even if it is homogeneous, the velocity distribution in each of the branch line inner regions 9... Can be accurately formed, and the accurately formed velocity distribution allows, for example, the branch line inner region 9 at a place where the speed is extremely low. In addition, destructive inspections such as the cause of the slow speed, that is, the presence of defects can be performed (see FIG. 20).

このように、逐次補正されるモデルにより、推定発信時刻の分散が最小となる発信点を求めることで、測定対象物の構成材料などに不均質部材が含まれていた場合、ひび割れや劣化など局所的な不均質箇所場合などを反映した発信点の位置特定（同定）が可能となるのである。 In this way, by obtaining a transmission point that minimizes the variance of the estimated transmission time by using a model that is sequentially corrected, if a heterogeneous member is included in the constituent material of the measurement object, local problems such as cracking and deterioration are observed. This makes it possible to specify (identify) the location of the transmission point reflecting the case of a typical inhomogeneous location.

さらに、発信点が増えれば、発信点の数だけ本発明の手法を行うことになり、その結果、さらに真の発信点の特定（同定）の精度が高くなり、精度の高い弾性波トモグラフィによる非破壊検査システムを提供できることになる。 Further, if the number of transmission points increases, the method of the present invention is performed by the number of transmission points, and as a result, the accuracy of identification (identification) of the true transmission point is further increased, and high-accuracy elastic wave tomography is used. A non-destructive inspection system can be provided.

すなわち、図２５に示すように、複数箇所に発生した複数のAE音１０・・・を発信情報として採用して本発明の手法を行うのである。これにより、詳細な測定対象物１の非破壊検査を行うことも出来る。 That is, as shown in FIG. 25, the method of the present invention is performed by adopting a plurality of AE sounds 10... Thereby, the nondestructive inspection of the detailed measuring object 1 can also be performed.

そして、本発明の主要な装置構成としては、ＡＥ音１０を受信するＡＥセンサ（受信波形計測センサ）、ＡＥ音の波形を記録する記録装置、及び表示装置、また真の発信点を解析する解析装置などが挙げられる。 The main device configuration of the present invention includes an AE sensor (received waveform measuring sensor) that receives the AE sound 10, a recording device that records the waveform of the AE sound, a display device, and an analysis that analyzes a true transmission point. Examples thereof include devices.

本発明の方法は、上記の装置を用いて行われ、まず、受信波形計測センサ３・・・を対象となる物性が不均質な測定対象物１の所定箇所へ設置し、地上側の記録装置や表示装置、解析装置へ有線接続若しくは無線接続し、所定期間、ＡＥ音１０によるＡＥ波を計測し、計測したデータは記録装置へ記録する。 The method of the present invention is performed using the above-described apparatus. First, the reception waveform measurement sensors 3... Are installed at predetermined positions of the measurement object 1 having non-homogeneous physical properties, and a recording apparatus on the ground side. The AE wave by the AE sound 10 is measured for a predetermined period, and the measured data is recorded in the recording device.

そして、記録装置により記録された記録（波形時刻歴）を用い、複数設置した受信波形計測センサ３・・・の各位置関係から、解析装置により真のＡＥ波受信箇所を解析・特定する。 Then, using the record (waveform time history) recorded by the recording device, the analysis device analyzes and identifies the true AE wave reception location from the respective positional relationships of the plurality of received waveform measuring sensors 3.

なお、解析・特定は、ひとつのAE音によるAE波を受信する複数のセンサで囲まれた領域内で得られることが基本とされる。
ここで得られた真の発信点のコンピュータへの記録は、いわゆる打音検査位置の自動記録にもなる。 Analysis / specification is basically obtained in an area surrounded by a plurality of sensors that receive AE waves from one AE sound.
The recording of the true transmission point obtained here to the computer is also an automatic recording of the so-called hammering test position.

すなわち、従来、弾性波トモグラフィのための測定対象物１の打音検査では、打音した位置を点検図に手書きで記録するため手間が掛かっていた。
しかるに、本発明では、この打音検査を実施する領域にセンサを設置して本発明を適用することにより、打音検査位置が座標データで自動的に記録できるからである。 That is, conventionally, in the sound hit inspection of the measuring object 1 for elastic wave tomography, it takes time to record the hit position in a check drawing by hand.
However, in the present invention, the sensor is installed in the area where the hammering test is performed and the present invention is applied, so that the hammering test position can be automatically recorded as coordinate data.

これは通常の打音検査のみならず、打撃や超音波入力を用いて健全性を評価する非破壊検査手法（リバウンドハンマ法、機械インピーダンス法、衝撃弾性波法、超音波法など）の検査位置も自動的に記録できるとのメリットがある。
This is not only a normal hammering test, but also a non-destructive testing method (rebound hammer method, mechanical impedance method, impact elastic wave method, ultrasonic method, etc.) that evaluates soundness using hammering or ultrasonic input. Has the advantage of being able to record automatically.

１測定対象物
２発信波形計測センサ
３受信波形計測センサ
４弾性波発信用器具
５解析モデル
６分岐点
７計測走時
８理論走時
９分岐線内領域
１０ AE音
２０検査領域
２２中間節点 1 Measurement Object 2 Transmitted Waveform Measurement Sensor 3 Received Waveform Measurement Sensor 4 Elastic Wave Transmitting Instrument 5 Analytical Model 6 Branch Point 7 Measurement Travel Time 8 Theoretical Travel Time 9 Branch Line Area 10 AE Sound 20 Inspection Area 22 Intermediate Node

Claims

Using the transmission time of the sound emitted from the measurement object, the transmission position and the reception time of the sound, the reception position, the actual elastic wave propagation time between the reception waveform measurement sensor and the transmission waveform measurement sensor is calculated,
An analysis model in which a plurality of branch points are provided between the transmission waveform measurement sensor and the reception waveform measurement sensor is formed, and an elastic wave propagation time as a theoretical value between the transmission waveform measurement sensor and the reception waveform measurement sensor is determined from the analysis model. And calculating the velocity distribution of the elastic wave propagation velocity in the branch line area branched at the branch point by calculating the elastic wave propagation time as the calculated theoretical value close to the actual elastic wave propagation time. A non-destructive inspection method for an object to be measured using tomographic analysis for forming and performing a destructive inspection with the formed velocity distribution,
A polyhedral inspection region is provided in a three-dimensional measurement object, and apexes of the polyhedral inspection region are formed on the surface of the measurement object, and reception waveform measurement sensors are installed at four or more formed vertices. The received waveform measurement sensor receives the sound emitted from the measurement object without using the transmission waveform measurement sensor, and the reception time and reception position specified by the reception waveform measurement sensor and the sound are received in plural. Calculated by using a mathematical expression that estimates the transmission time and transmission position based on the value of the same propagation velocity set when reaching the waveform measurement sensor, to determine the estimated transmission time and estimated transmission position of the emitted sound,
In the non-destructive inspection method of the measurement object that performs the tomography analysis using the obtained estimated transmission time and the estimated transmission position value,
When the measurement object is composed of inhomogeneous physical properties, the inspection region or the inspection region is appropriately set instead of the value of the same propagation velocity set when the sound reaches a plurality of received waveform measurement sensors. In the divided small areas, the propagation speed value corresponding to the heterogeneous physical properties is calculated using mathematical formulas, and the estimated transmission time and estimated transmission position of the sound emitted using the calculated different propagation speed values. To calculate
The calculation is repeated until the reception times specified by the plurality of received waveform measurement sensors are substantially equal, and the propagation speed in a small area obtained by appropriately dividing the inspection area or the inspection area is obtained, and the obtained Determine the velocity distribution of the propagation velocity for each of the inspection areas of the measurement object or the small areas obtained by appropriately dividing the inspection area according to the difference in propagation velocity, and configure the measurement object based on the obtained velocity distribution of the measurement object When the material contains an inhomogeneous substance, the true transmission position and the transmission time of the sound reflecting the cracked or deteriorated inhomogeneous part can be specified, and the inspection area or the small area obtained by dividing the inspection area as appropriate The degradation status of the measurement object at can be specified,
A method of simultaneously specifying a transmission point and a physical property state (deterioration state) in elastic wave tomography performed on a measurement object of heterogeneous physical properties.

Using the transmission time of the sound emitted from the measurement object, the transmission position and the reception time of the sound, the reception position, the actual elastic wave propagation time between the reception waveform measurement sensor and the transmission waveform measurement sensor is calculated,
An analysis model in which a plurality of branch points are provided between the transmission waveform measurement sensor and the reception waveform measurement sensor is formed, and an elastic wave propagation time as a theoretical value between the transmission waveform measurement sensor and the reception waveform measurement sensor is determined from the analysis model. And calculating the velocity distribution of the elastic wave propagation velocity in the branch line area branched at the branch point by calculating the elastic wave propagation time as the calculated theoretical value close to the actual elastic wave propagation time. A non-destructive inspection method for an object to be measured using tomographic analysis for forming and performing a destructive inspection with the formed velocity distribution,
Without using the transmission waveform measurement sensor, the sound emitted from the measurement object is provided with an inspection area so as to form a polygon on the surface of the measurement object, and a plurality of sounds are installed at positions that are at least the vertexes of the polygon. Received by the received waveform measurement sensor, and the transmission time based on the reception time specified by the received waveform measurement sensor, the reception position, and the value of the same propagation velocity set when the sound reaches a plurality of received waveform measurement sensors. And calculating using the mathematical formula for estimating the transmission position, and determining the estimated transmission time and estimated transmission position of the emitted sound,
In the non-destructive inspection method of the measurement object that performs the tomography analysis using the obtained estimated transmission time and the estimated transmission position value,
When the measurement object is composed of inhomogeneous physical properties, the inspection region or the inspection region is appropriately set instead of the value of the same propagation velocity set when the sound reaches a plurality of received waveform measurement sensors. In the divided small areas, the propagation speed value corresponding to the heterogeneous physical properties is calculated using mathematical formulas, and the estimated transmission time and estimated transmission position of the sound emitted using the calculated different propagation speed values. To calculate
The calculation is repeated until the reception times specified by the plurality of reception waveform measurement sensors are substantially equal to each other , and the propagation speed in the inspection region or a small region obtained by appropriately dividing the inspection region is obtained and obtained. The velocity distribution of the propagation velocity is obtained for each of the inspection regions of the measurement object or the small areas obtained by appropriately dividing the inspection region according to the difference in the propagation velocity, and the measurement object is measured by the velocity distribution of the obtained measurement objects. When the component material contains an inhomogeneous material, cracks, and the sound's true transmission position and transmission time reflecting the inhomogeneous portion of the deterioration can be specified, and the inspection region or a small region obtained by dividing the inspection region as appropriate The deterioration status of the measurement object can be specified in
A method of simultaneously specifying a transmission point and a physical property state (deterioration state) in elastic wave tomography performed on a measurement object of heterogeneous physical properties.

The sound emitted from the measurement object is an AE sound that is a minute sound naturally generated by an external force load.
The method for simultaneously specifying a transmission point / physical property state (deterioration state) in elastic wave tomography performed on a measurement object having heterogeneous physical properties according to claim 1, characterized in that:

The measurement object consisting of the heterogeneous physical properties is a bridge floor board or a highway floor board that can use AE sound that naturally occurs due to traffic load as transmission information.
The transmission point / physical property status (deterioration status) simultaneous identification method in elastic wave tomography performed for a measurement object having heterogeneous physical properties according to any one of claims 1 to 3.