JP2017166953A - Method and apparatus for evaluating damage of composite material - Google Patents

Method and apparatus for evaluating damage of composite material Download PDF

Info

Publication number
JP2017166953A
JP2017166953A JP2016052030A JP2016052030A JP2017166953A JP 2017166953 A JP2017166953 A JP 2017166953A JP 2016052030 A JP2016052030 A JP 2016052030A JP 2016052030 A JP2016052030 A JP 2016052030A JP 2017166953 A JP2017166953 A JP 2017166953A
Authority
JP
Japan
Prior art keywords
test piece
stress
signal
composite material
pseudo
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.)
Granted
Application number
JP2016052030A
Other languages
Japanese (ja)
Other versions
JP6165908B1 (en
Inventor
拓 川▲崎▼
Hiroshi Kawasaki
拓 川▲崎▼
真実 滝沢
Mami Takizawa
真実 滝沢
征一 大森
Seiichi Omori
征一 大森
佐々木 孝明
Takaaki Sasaki
孝明 佐々木
敬弘 荒川
Takahiro Arakawa
敬弘 荒川
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
IHI Inspection and Instrumentation Co Ltd
Original Assignee
IHI Inspection and Instrumentation Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by IHI Inspection and Instrumentation Co Ltd filed Critical IHI Inspection and Instrumentation Co Ltd
Priority to JP2016052030A priority Critical patent/JP6165908B1/en
Application granted granted Critical
Publication of JP6165908B1 publication Critical patent/JP6165908B1/en
Publication of JP2017166953A publication Critical patent/JP2017166953A/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for evaluating the damage of a composite material, capable of repeatedly acquiring a lot of data on the same conditions, easily finding a frequency change point and thereby properly evaluating the damaged state of a test piece.SOLUTION: A method for evaluating the damage of a composite material comprises: (S1) attaching an ultrasonic vibration source and an ultrasonic receiving sensor to a test piece consisting of a composite material at an interval; (S2) sequentially increasing a tensile load to repeat a stress load and a stress load removal to the test piece; (S3) transmitting a pseudo AE signal from the ultrasonic vibration source when stress-loaded to receive the pseudo AE signal propagating the test piece by the ultrasonic receiving sensor; (S4) performing the frequency analysis of the received signal; and (S5) acquiring the amplitude value of a time waveform in a low frequency wave region to evaluate the existence of the damage of the test piece from change in the amplitude value.SELECTED DRAWING: Figure 4

Description

本発明は、複合材料の損傷評価方法と装置に関する。   The present invention relates to a damage evaluation method and apparatus for composite materials.

繊維強化複合材料(FRP:Fiber Reinforced Plastic)は、ロケットや航空機などに用いられている。特に、炭素繊維強化複合材料(CFRP:Carbon Fiber Reinforced Plastic)は、強度と剛性に優れている。FRPでは、積層の剥離や繊維の断線が生じた後に破壊に至る。   Fiber reinforced composite materials (FRP: Fiber Reinforced Plastic) are used in rockets and aircraft. In particular, carbon fiber reinforced composite material (CFRP: Carbon Fiber Reinforced Plastic) is excellent in strength and rigidity. In FRP, breakage occurs after delamination and fiber breakage occur.

このようなFRPの引張強度を検査するために、カイザー効果を利用することが行われている。カイザー効果とは、材料に引張荷重を与え、再び、材料に引張荷重を与える場合に、この引張荷重が先に与えた引張荷重に至るまでは、材料にAE波(acoustic emissionによる音波)が生じない現象である。なお、AE波は、材料の変形や破壊などにより、材料に発生する音波である。カイザー効果は、健全な材料において得られる。   In order to inspect the tensile strength of such FRP, the Kaiser effect is used. The Kaiser effect means that when a tensile load is applied to a material and then a tensile load is applied to the material again, AE waves (acoustic emission sound waves) are generated in the material until the tensile load reaches the previously applied tensile load. There is no phenomenon. The AE wave is a sound wave generated in the material due to deformation or destruction of the material. The Kaiser effect is obtained with sound materials.

カイザー効果を利用する複合材料の損傷評価方法として、例えば特許文献1が既に提案されている。
特許文献1の「強度検査方法および強度評価用データ出力装置」は、カイザー効果の成立範囲では負荷応力に比例して重心周波数集中部が高くなり、損傷が発生すると、重心周波数集中部が低下することを利用している。
As a damage evaluation method for a composite material using the Kaiser effect, for example, Patent Document 1 has already been proposed.
In the “strength inspection method and strength evaluation data output device” of Patent Document 1, the center-of-gravity frequency concentration portion increases in proportion to the load stress within the range where the Kaiser effect is established, and the center-of-gravity frequency concentration portion decreases when damage occurs. I use that.

特許第5841081号公報Japanese Patent No. 5841081

上述した従来の方法では、負荷応力の上昇時に、重心周波数集中部が増加から減少に変化する「周波数変化点」を検出する。そのため、重心周波数のデータを多数必要とする。
しかし、従来の方法では、負荷応力の上昇中に発生するAE波を計測するため、AE波の計測が一過性であり、同一条件での計測の繰り返しができず、データが不足する可能性があった。
そのため、重心周波数集中部の変化点(すなわち周波数変化点)を見つけ難く、検出漏れや検出誤差が生じる可能性があった。
In the conventional method described above, when the load stress increases, a “frequency change point” at which the center of gravity frequency concentration portion changes from increasing to decreasing is detected. For this reason, a large amount of data on the centroid frequency is required.
However, in the conventional method, since the AE wave generated while the load stress is rising is measured, the measurement of the AE wave is temporary, and the measurement under the same condition cannot be repeated, and the data may be insufficient. was there.
Therefore, it is difficult to find a change point (that is, a frequency change point) of the center-of-gravity frequency concentration portion, and there is a possibility that a detection omission or a detection error occurs.

本発明は、上述した問題点を解決するために創案されたものである。すなわち、本発明の目的は、同一条件で多数のデータを繰り返し取得することができ、かつ周波数変化点を容易に見つけることができ、これにより試験片の損傷状態を的確に評価することができる複合材料の損傷評価方法と装置を提供することにある。   The present invention has been developed to solve the above-described problems. That is, an object of the present invention is a composite that can repeatedly acquire a large number of data under the same conditions and can easily find a frequency change point, thereby accurately evaluating the damaged state of the test piece. It is an object of the present invention to provide a material damage evaluation method and apparatus.

本発明によれば、(A)超音波発振源と超音波受信センサを複合材料からなる試験片に間隔を隔てて取り付け、
(B)引張荷重を順に増加させて、前記試験片に応力負荷と応力除荷を繰り返し、
(C)応力負荷時に、前記超音波発振源から疑似AE信号を発信し、前記試験片を伝搬した前記疑似AE信号を、前記超音波受信センサにより受信し、
(D)受信信号を周波数解析して、低周波域の時間波形の振幅値を取得し、
(E)前記振幅値の変化から、前記試験片の損傷の有無を評価する、複合材料の損傷評価方法が提供される。
According to the present invention, (A) an ultrasonic oscillation source and an ultrasonic reception sensor are attached to a test piece made of a composite material at an interval,
(B) Increase the tensile load in order and repeat the stress load and stress unload on the test piece,
(C) At the time of stress loading, a pseudo AE signal is transmitted from the ultrasonic oscillation source, and the pseudo AE signal propagated through the test piece is received by the ultrasonic reception sensor,
(D) Analyzing the frequency of the received signal to obtain the amplitude value of the time waveform in the low frequency range,
(E) A composite material damage evaluation method is provided that evaluates the presence or absence of damage to the test piece from the change in the amplitude value.

前記(E)において、前記応力負荷時における前記低周波域の前記振幅値が、負荷応力の増加につれて減少から増加に変化する場合に、その変化点の前記負荷応力を前記試験片の引張強度と評価する。   In (E), when the amplitude value of the low frequency region at the time of the stress load changes from decrease to increase as the load stress increases, the load stress at the change point is set as the tensile strength of the test piece. evaluate.

前記(E)において、前記応力負荷時における前記低周波域の前記振幅値が、負荷応力の増加につれて減少する場合に、前記試験片の損傷なしと評価し、増加する場合に、前記試験片の損傷有りと評価する。   In (E), when the amplitude value of the low frequency region at the time of the stress load decreases as the load stress increases, it is evaluated that the test piece is not damaged. Evaluated as damaged.

前記(C)において、さらに応力除荷時に、前記超音波発振源から前記疑似AE信号を発信し、前記試験片を伝搬した前記疑似AE信号を、前記超音波受信センサにより受信し、
前記(D)において、受信信号を周波数解析して、さらに高周波域の時間波形の前記振幅値を取得し、
前記(E)において、前記応力除荷時における前記低周波域及び前記高周波域の前記振幅値が、負荷応力の増加につれて低下する場合に、前記試験片の損傷有りと評価する。
In (C), when the stress is unloaded, the pseudo AE signal is transmitted from the ultrasonic oscillation source, and the pseudo AE signal propagated through the test piece is received by the ultrasonic receiving sensor.
In (D), the received signal is subjected to frequency analysis, and the amplitude value of the time waveform in the high frequency region is obtained,
In (E), when the amplitude values in the low frequency range and the high frequency range at the time of stress unloading decrease as the load stress increases, it is evaluated that the test piece is damaged.

前記超音波発振源と前記超音波受信センサは、AEセンサである。   The ultrasonic oscillation source and the ultrasonic reception sensor are AE sensors.

最初の応力負荷前に、前記超音波発振源から発信される前記疑似AE信号を周波数解析して、その重心周波数又はその近傍を境にして、その下方を前記低周波域に、その上方を高周波域に設定する。   Before the first stress load, the pseudo AE signal transmitted from the ultrasonic oscillation source is subjected to frequency analysis, with the center of gravity frequency or the vicinity thereof as a boundary, the lower part is the low frequency region, and the upper part is the high frequency part. Set to the area.

前記低周波域は、0〜150kHzであり、前記高周波域は、150〜850kHzである。   The low frequency region is 0 to 150 kHz, and the high frequency region is 150 to 850 kHz.

また本発明によれば、複合材料からなる試験片に間隔を隔てて取り付けられる超音波発振源及び超音波受信センサと、
引張荷重を順に増加させて、前記試験片に応力負荷と応力除荷を繰り返す引張試験装置と、
応力負荷時に、前記超音波発振源から疑似AE信号を発信し、前記試験片を伝搬した前記疑似AE信号を、前記超音波受信センサにより受信するAE装置と、
受信信号を周波数解析して、低周波域の時間波形の振幅値を取得し、前記振幅値の変化から、前記試験片の損傷の有無を評価する制御解析装置と、を備えた複合材料の損傷評価装置が提供される。
Further, according to the present invention, an ultrasonic oscillation source and an ultrasonic reception sensor that are attached to a test piece made of a composite material at an interval,
A tensile test device that increases the tensile load in order and repeats stress loading and unloading on the test piece,
An AE device that transmits a pseudo AE signal from the ultrasonic oscillation source during stress loading and receives the pseudo AE signal propagated through the test piece by the ultrasonic reception sensor;
Frequency analysis of received signal to obtain amplitude value of time waveform in low frequency range, and control analysis device for evaluating presence or absence of damage of test specimen from change of amplitude value, damage to composite material An evaluation device is provided.

前記AE装置は、さらに応力除荷時に、前記超音波発振源から前記疑似AE信号を発信し、前記試験片を伝搬した前記疑似AE信号を、前記超音波受信センサにより受信する。   The AE device further transmits the pseudo AE signal from the ultrasonic oscillation source at the time of stress unloading, and receives the pseudo AE signal propagated through the test piece by the ultrasonic receiving sensor.

前記制御解析装置は、前記受信信号を周波数解析して、さらに高周波域の時間波形の前記振幅値を取得し、前記振幅値の変化から、前記試験片の損傷の有無を評価する。   The control analysis device analyzes the frequency of the received signal, obtains the amplitude value of a time waveform in a high frequency region, and evaluates whether or not the test piece is damaged from the change in the amplitude value.

上記本発明の方法と装置によれば、超音波発振源(例えば、AEセンサ)から疑似AE信号を発信し、試験片を伝搬した疑似AE信号を、超音波受信センサ(例えば、AEセンサ)により受信する。さらに、受信した疑似AE信号から、試験片の損傷の有無を評価する。
従って、実際に発生するAE波でなく、疑似AE信号を発信し受信するので、同一条件で多数の受信信号を繰り返し取得することができる。
According to the method and apparatus of the present invention, a pseudo AE signal is transmitted from an ultrasonic oscillation source (for example, AE sensor), and the pseudo AE signal propagated through the test piece is transmitted by the ultrasonic reception sensor (for example, AE sensor). Receive. Furthermore, the presence or absence of damage to the test piece is evaluated from the received pseudo AE signal.
Therefore, since a pseudo AE signal is transmitted and received instead of an actually generated AE wave, a large number of received signals can be repeatedly acquired under the same conditions.

すなわち本発明によれば、多数のデータから周波数変化点を容易に見つけることができ、これにより試験片の損傷状態を的確に評価することができる。   That is, according to the present invention, it is possible to easily find a frequency change point from a large number of data, and thereby it is possible to accurately evaluate the damaged state of the test piece.

本発明による複合材料の損傷評価装置の全体構成図である。It is a whole block diagram of the damage evaluation apparatus of the composite material by this invention. 試験片の説明図である。It is explanatory drawing of a test piece. 引張試験時の負荷パターンを示す図である。It is a figure which shows the load pattern at the time of a tension test. 本発明による複合材料の損傷評価方法の全体フロー図である。It is a whole flowchart of the damage evaluation method of the composite material by this invention. 応力負荷前に取得した疑似AE信号の周波数解析結果を示す図である。It is a figure which shows the frequency analysis result of the pseudo | simulation AE signal acquired before stress load. 応力除荷時の試験結果を示す図である。It is a figure which shows the test result at the time of stress unloading. 応力負荷時の試験結果を示す図である。It is a figure which shows the test result at the time of stress load.

以下、本発明の実施形態を、図面を参照して説明する。なお各図において、共通する部分には同一の符号を付し、重複した説明は省略する。   Embodiments of the present invention will be described below with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

図1は、本発明による複合材料の損傷評価装置10の全体構成図である。
この図において、本発明の損傷評価装置10は、超音波発振源12及び超音波受信センサ14、引張試験装置16、AE装置18、及び制御解析装置20を備える。
FIG. 1 is an overall configuration diagram of a composite material damage evaluation apparatus 10 according to the present invention.
In this figure, the damage evaluation apparatus 10 of the present invention includes an ultrasonic oscillation source 12 and an ultrasonic reception sensor 14, a tensile test apparatus 16, an AE apparatus 18, and a control analysis apparatus 20.

超音波発振源12及び超音波受信センサ14は、好ましくはAEセンサ(例えば圧電素子)であり、複合材料からなる試験片1に間隔を隔てて取り付けられる。
試験片1は、例えばFRP,CFRPなどの平板であるのがよい。
図2は、後述する実施例で使用した試験片1の説明図である。この実施例では、長さL=200mm、幅W=12.5mm、厚さt=3mmの試験片1を用いた。超音波発振源12と超音波受信センサ14のセンサ間距離L1は100mmであった。
The ultrasonic oscillation source 12 and the ultrasonic reception sensor 14 are preferably AE sensors (for example, piezoelectric elements), and are attached to the test piece 1 made of a composite material at an interval.
The test piece 1 is preferably a flat plate such as FRP or CFRP.
FIG. 2 is an explanatory diagram of the test piece 1 used in Examples described later. In this example, a test piece 1 having a length L = 200 mm, a width W = 12.5 mm, and a thickness t = 3 mm was used. The inter-sensor distance L1 between the ultrasonic oscillation source 12 and the ultrasonic reception sensor 14 was 100 mm.

引張試験装置16は、引張荷重Pを順に増加させて、試験片1に応力負荷と応力除荷を繰り返す。
図3は、後述する実施例における引張試験時の負荷パターンを示す図である。この実施例では、200時間毎に負荷応力を133MPaずつ増加させ、133,266,399,532,665,798MPaの応力負荷と、その間の応力除荷とを繰り返した。
The tensile test apparatus 16 increases the tensile load P in order, and repeats stress loading and stress unloading on the test piece 1.
FIG. 3 is a diagram showing a load pattern during a tensile test in Examples described later. In this example, the load stress was increased by 133 MPa every 200 hours, and the stress load of 133,266,399,532,665,798 MPa and the stress unloading in the meantime were repeated.

図1において、AE装置18は、応力負荷時に、超音波発振源12から疑似AE信号2を発信し、試験片1を伝搬した疑似AE信号3を、超音波受信センサ14により受信する。なお、AE装置18は、さらに応力除荷時に、同様に、疑似AE信号2を発信し、疑似AE信号3を受信することが好ましい。
以下、発信する疑似AE信号2を「発信信号2」、受信する疑似AE信号3を「受信信号3」と呼ぶ。
In FIG. 1, the AE device 18 transmits a pseudo AE signal 2 from the ultrasonic oscillation source 12 and receives the pseudo AE signal 3 propagated through the test piece 1 by the ultrasonic reception sensor 14 when stress is applied. In addition, it is preferable that the AE device 18 similarly transmits the pseudo AE signal 2 and receives the pseudo AE signal 3 at the time of stress unloading.
Hereinafter, the pseudo AE signal 2 to be transmitted is referred to as “transmission signal 2”, and the pseudo AE signal 3 to be received is referred to as “reception signal 3”.

制御解析装置20は、例えばコンピュータ(PC)であり、受信信号3(すなわち疑似AE信号3)を周波数解析して、低周波域の時間波形の振幅値を取得し、振幅値の変化から、試験片1の損傷の有無を評価する。なお、制御解析装置20は、受信信号3を周波数解析して、さらに高周波域の時間波形の振幅値を取得し、振幅値の変化から、試験片1の損傷の有無を評価することが好ましい。
なお、「時間波形」とは、横軸が時間、縦軸が出力波形の関係を示すデータである。
The control analysis device 20 is, for example, a computer (PC), performs frequency analysis on the received signal 3 (that is, the pseudo AE signal 3), acquires an amplitude value of a time waveform in a low frequency region, and performs a test from a change in the amplitude value. The presence or absence of damage to the piece 1 is evaluated. In addition, it is preferable that the control analysis device 20 performs frequency analysis on the received signal 3, further acquires an amplitude value of a time waveform in a high frequency region, and evaluates whether or not the test piece 1 is damaged from a change in the amplitude value.
“Time waveform” is data indicating the relationship between time on the horizontal axis and the output waveform on the vertical axis.

図4は、本発明による複合材料の損傷評価方法の全体フロー図である。
この図において、本発明の方法は、S1〜S5の各ステップ(工程)からなる。
FIG. 4 is an overall flowchart of the composite material damage evaluation method according to the present invention.
In this figure, the method of the present invention comprises steps (steps) S1 to S5.

ステップS1(センサ取り付け)では、超音波発振源12と超音波受信センサ14を複合材料からなる試験片1にセンサ間距離L1を隔てて取り付ける。この取り付けは、試験片1の表面に接着剤を用いて固定し、超音波がスムーズに送信し受信できるようにする。   In step S1 (sensor attachment), the ultrasonic oscillation source 12 and the ultrasonic reception sensor 14 are attached to the test piece 1 made of a composite material with a distance L1 between the sensors. This attachment is fixed to the surface of the test piece 1 with an adhesive so that ultrasonic waves can be transmitted and received smoothly.

ステップS2(引張試験)では、引張荷重Pを順に増加させて、試験片1に応力負荷と応力除荷を繰り返す。引張荷重Pは、例えば上述した図3の負荷パターンであるのがよい。
また、ステップS2において、最初の応力負荷前に、超音波発振源12から発信される疑似AE信号2(発信信号2)を周波数解析して、その重心周波数又はその近傍を境にして、その下方を低周波域に、その上方を高周波域に設定する。
なお、「重心周波数」とは、AE信号の周波数解析結果におけるスペクトルの代表値である。重心とは、加重平均値を指しており、周波数における成分強度の積和を、成分強度の総和で割った値となる。
後述する実施例において、低周波域は、0〜150kHzであり、高周波域は、150〜850kHzである。
In step S2 (tensile test), the tensile load P is increased in order, and the stress load and the stress unloading are repeated on the test piece 1. The tensile load P is preferably the load pattern of FIG. 3 described above, for example.
Further, in step S2, before the first stress load, the pseudo AE signal 2 (transmitted signal 2) transmitted from the ultrasonic oscillation source 12 is frequency-analyzed, and below the center of gravity frequency or its vicinity, Is set to the low frequency range and the upper part is set to the high frequency range.
The “centroid frequency” is a representative value of the spectrum in the frequency analysis result of the AE signal. The center of gravity refers to a weighted average value, which is a value obtained by dividing the product sum of the component intensities at the frequency by the sum of the component intensities.
In the examples described later, the low frequency region is 0 to 150 kHz, and the high frequency region is 150 to 850 kHz.

ステップS3(信号受信)では、応力負荷時に、超音波発振源12から疑似AE信号2を発信し、試験片1を伝搬した疑似AE信号3を、超音波受信センサ14により受信する。
また、ステップS3において、さらに応力除荷時に、同様に、疑似AE信号2を発信し、疑似AE信号3を受信することが好ましい。
In step S3 (signal reception), at the time of stress loading, the pseudo AE signal 2 is transmitted from the ultrasonic oscillation source 12, and the pseudo AE signal 3 propagated through the test piece 1 is received by the ultrasonic reception sensor 14.
Further, in step S3, it is preferable that the pseudo AE signal 2 is similarly transmitted and the pseudo AE signal 3 is received when the stress is unloaded.

ステップS4(周波数解析)では、受信信号3を周波数解析して、低周波域の時間波形の振幅値を取得する。
また、ステップS4において、同様に、受信信号3を周波数解析して、さらに高周波域の時間波形の振幅値を取得することが好ましい。
In step S4 (frequency analysis), the received signal 3 is frequency-analyzed to obtain the amplitude value of the time waveform in the low frequency region.
Similarly, in step S4, similarly, it is preferable that the received signal 3 is subjected to frequency analysis to obtain an amplitude value of a time waveform in a higher frequency range.

ステップS5(評価)では、振幅値の変化から、試験片1の損傷の有無を評価する。   In step S5 (evaluation), the presence or absence of damage to the test piece 1 is evaluated from the change in the amplitude value.

例えば、ステップS5において、応力負荷時における低周波域の振幅値が、負荷応力の増加につれて減少から増加に変化する場合に、その変化点(すなわち周波数変化点)の負荷応力を試験片1の引張強度と評価する。   For example, when the amplitude value in the low frequency region at the time of stress loading changes from decrease to increase as the load stress increases in step S5, the load stress at the change point (that is, the frequency change point) is determined as the tensile strength of the test piece 1. Assess with strength.

また、ステップS5において、応力負荷時における低周波域の振幅値が、負荷応力の増加につれて減少する場合に、試験片1の「損傷なし」と評価し、増加する場合に、試験片1の「損傷有り」と評価する。   Further, in step S5, when the amplitude value in the low frequency region at the time of stress load decreases as the load stress increases, the test piece 1 is evaluated as “no damage”. Evaluated as “damaged”.

さらに、ステップS5において、応力除荷時における低周波域及び高周波域の振幅値が、負荷応力の増加につれて低下する場合に、試験片1の「損傷有り」と評価する。   Further, in step S5, when the amplitude values in the low frequency range and the high frequency range during stress unloading decrease as the load stress increases, the test piece 1 is evaluated as “damaged”.

以下、本発明の実施例を説明する。   Examples of the present invention will be described below.

(試験概要)
トレカプリプレグT700SCを0−45−90に積層し、L200×W12.5×t3mmとしたCFRP試験片(試験片1)を用いた。AEセンサ(超音波発振源12と超音波受信センサ14)として、富士セラミックス社製AE144Aを2個使用し、試験片1の中央から50mmの位置にそれぞれ設置した(センサ間距離L1=100mm)。
一方のAEセンサ(超音波発振源12)よりパルス信号(疑似AE信号2)を励起し、他方のAEセンサ(超音波受信センサ14)で受信することにより超音波の伝搬傾向を確認した。
引張試験は、図3に示した負荷パターンで、試験片1が破断(本試験では829MPa)するまで実施し、その過程で133MPa毎に負荷応力を除荷し、除荷時と応力負荷時の二つのタイミングで超音波伝搬傾向の確認を行った。
(Study outline)
A CFRP test piece (test piece 1) in which Trecapprepreg T700SC was laminated on 0-45-90 and L200 × W12.5 × t3 mm was used. Two AE 144A manufactured by Fuji Ceramics Co., Ltd. were used as the AE sensors (the ultrasonic oscillation source 12 and the ultrasonic reception sensor 14), and each was installed at a position 50 mm from the center of the test piece 1 (inter-sensor distance L1 = 100 mm).
A pulse signal (pseudo AE signal 2) was excited from one AE sensor (ultrasonic oscillation source 12) and received by the other AE sensor (ultrasonic reception sensor 14), and the propagating tendency of ultrasonic waves was confirmed.
The tensile test is performed until the test piece 1 breaks (829 MPa in the present test) with the load pattern shown in FIG. 3, and the load stress is unloaded every 133 MPa in the process. The ultrasonic wave propagation tendency was confirmed at two timings.

(試験結果)
図5は、応力負荷前に取得した疑似AE信号2の周波数解析結果を示す図である。この図において、横軸は周波数、縦軸は信号強度である。またこの図における重心周波数は、約150kHzであった。
(Test results)
FIG. 5 is a diagram showing the frequency analysis result of the pseudo AE signal 2 acquired before stress loading. In this figure, the horizontal axis represents frequency and the vertical axis represents signal intensity. The center-of-gravity frequency in this figure was about 150 kHz.

図5から、80kHz近傍と、200kHz近傍にスペクトラムのピークを確認することができる。そのため、0〜150kHz(低周波域)と150〜850kHz(高周波域)の二つの周波数域で、試験片1を伝搬した超音波における時間波形の振幅値を比較した。   From FIG. 5, spectrum peaks can be confirmed in the vicinity of 80 kHz and in the vicinity of 200 kHz. Therefore, the amplitude value of the time waveform in the ultrasonic wave which propagated through the test piece 1 was compared in two frequency ranges of 0 to 150 kHz (low frequency range) and 150 to 850 kHz (high frequency range).

図6は、応力除荷時の試験結果を示す図であり、図7は、応力負荷時の試験結果を示す図である。   FIG. 6 is a diagram showing a test result at the time of stress unloading, and FIG. 7 is a diagram showing a test result at the time of stress loading.

各図において、横軸は試験片1に負荷した応力であり、縦軸は受信信号3の最大振幅値である。なお図中の丸印(○)は低周波域、菱形(◇)は高周波域における時間波形の最大振幅値を示している。また、図中に矢印Aで示す点線は引張試験中におけるAE信号の重心周波数集中部が低下した応力を示す。
「重心周波数集中部」とは、横軸に時間、縦軸に重心周波数をプロットした図において、プロットした点が集中する部分を意味する。言い換えれば、矢印Aで示す応力において、試験片1は損傷を受けているといえる。
なお、矢印Bで示す点線は試験片1の破断時の応力である。
In each figure, the horizontal axis represents the stress applied to the test piece 1, and the vertical axis represents the maximum amplitude value of the received signal 3. In the figure, the circle (◯) indicates the maximum amplitude value of the time waveform in the low frequency region, and the diamond (◇) indicates the time waveform in the high frequency region. In addition, the dotted line indicated by the arrow A in the figure indicates the stress at which the center of gravity frequency concentration portion of the AE signal is reduced during the tensile test.
The “centroid frequency concentration portion” means a portion where the plotted points are concentrated in the graph in which time is plotted on the horizontal axis and the center frequency is plotted on the vertical axis. In other words, it can be said that the test piece 1 is damaged in the stress indicated by the arrow A.
In addition, the dotted line shown by the arrow B is the stress at the time of fracture of the test piece 1.

図6において、応力除荷時に取得した受信信号3では、負荷応力が高くなるにつれて受信信号3の振幅値が低くなっている。このことは、材料中の損傷が大きくなり、音が通り難くなったため、受信信号3が減衰していると考えることができる。   In FIG. 6, in the received signal 3 acquired at the time of stress unloading, the amplitude value of the received signal 3 decreases as the load stress increases. This can be considered that the received signal 3 is attenuated because the damage in the material has increased and it has become difficult for sound to pass through.

一方、図7において、応力負荷時の受信信号3を確認すると、高周波域はほぼ一定、ないし少し減衰傾向にあるが、低周波域の結果では300〜400MPa付近から受信信号3の振幅値が高くなっている。
このことより、応力負荷時では超音波の伝搬傾向が変化し、試験片1の損傷後(矢印Aで示す点線より右側)は、損傷により音が通り難くなっているにも関わらず、低周波域の信号が増幅されることが確認できた。
On the other hand, in FIG. 7, when the received signal 3 at the time of stress loading is confirmed, the high frequency range is almost constant or slightly attenuated. However, in the low frequency range result, the amplitude value of the received signal 3 is high from around 300 to 400 MPa. It has become.
From this, the propagation tendency of the ultrasonic wave changes at the time of stress loading, and after the test piece 1 is damaged (right side from the dotted line indicated by the arrow A), although the sound is difficult to pass due to the damage, the low frequency It was confirmed that the signal of the region was amplified.

上述したように、本発明により、試験体(試験片1)が健全であれば負荷した応力に比例するように重心周波数集中部が高くなり、損傷が発生した際には重心周波数集中部が低くなることを確認した。   As described above, according to the present invention, if the specimen (test piece 1) is healthy, the center-of-gravity frequency concentration portion is increased in proportion to the applied stress, and when damage occurs, the center-of-gravity frequency concentration portion is decreased. It was confirmed that

また上述した実施例から、上述したステップS5において、応力負荷時における低周波域の振幅値が、負荷応力の増加につれて減少から増加に変化する場合に、その変化点の負荷応力を試験片1の引張強度と評価する、ことができる。   Further, from the above-described embodiment, when the amplitude value in the low frequency region at the time of stress loading changes from a decrease to an increase as the load stress increases in the above-described step S5, the load stress at the change point of the test piece 1 is determined. It can be evaluated as tensile strength.

また、ステップS5において、応力負荷時における低周波域の振幅値が、負荷応力の増加につれて減少する場合に、試験片1の損傷なしと評価し、増加する場合に、試験片1の損傷有りと評価する、ことができる。   In step S5, when the amplitude value in the low frequency region at the time of stress load decreases as the load stress increases, it is evaluated that the test piece 1 is not damaged, and when it increases, it is determined that the test piece 1 is damaged. Can be evaluated.

さらに、ステップS5において、応力除荷時における低周波域及び高周波域の振幅値が、負荷応力の増加につれて低下する場合に、試験片1の損傷有りと評価する、ことができる。   Furthermore, in step S5, when the amplitude values in the low frequency range and the high frequency range during stress unloading decrease as the load stress increases, it can be evaluated that the test piece 1 is damaged.

上述した本発明の方法と装置によれば、超音波発振源12(例えば、AEセンサ)から疑似AE信号2(発信信号2)を発信し、試験片1を伝搬した疑似AE信号3(受信信号3)を、超音波受信センサ14(例えば、AEセンサ)により受信する。さらに、受信した疑似AE信号3(受信信号3)から、試験片1の損傷の有無を評価する。
従って、実際に発生するAE波でなく、疑似AE信号2,3を発信し受信するので、同一の試験片1を用いて、同一条件で多数の受信信号3を繰り返し取得することができる。
According to the above-described method and apparatus of the present invention, the pseudo AE signal 2 (transmission signal 2) is transmitted from the ultrasonic oscillation source 12 (for example, AE sensor) and propagated through the test piece 1 (reception signal). 3) is received by the ultrasonic wave reception sensor 14 (for example, AE sensor). Further, the presence or absence of damage to the test piece 1 is evaluated from the received pseudo AE signal 3 (received signal 3).
Therefore, since the pseudo AE signals 2 and 3 are transmitted and received instead of the actually generated AE wave, a large number of received signals 3 can be repeatedly obtained under the same conditions using the same test piece 1.

すなわち本発明によれば、多数のデータから周波数変化点を容易に見つけることができ、これにより試験片1の損傷状態を的確に評価することができる。   That is, according to the present invention, it is possible to easily find the frequency change point from a large number of data, and thereby the damage state of the test piece 1 can be accurately evaluated.

なお、本発明は、上述した実施形態に限定されず、本発明の要旨を逸脱しない範囲で種々に変更することができることは勿論である。   In addition, this invention is not limited to embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.

P 引張荷重、1 試験片(FRP,CFRP)、
2 疑似AE信号(発信信号)、3 疑似AE信号(受信信号)、
10 損傷評価装置、12 超音波発振源(AEセンサ)、
14 超音波受信センサ(AEセンサ)、16 引張試験装置、
18 AE装置、20 制御解析装置(PC)
P tensile load, 1 test piece (FRP, CFRP),
2 pseudo AE signal (transmission signal), 3 pseudo AE signal (reception signal),
10 damage evaluation device, 12 ultrasonic oscillation source (AE sensor),
14 ultrasonic receiving sensor (AE sensor), 16 tensile testing device,
18 AE equipment, 20 Control analysis equipment (PC)

前記(C)において、さらに応力除荷時に、前記超音波発振源から前記疑似AE信号を発信し、前記試験片を伝搬した前記疑似AE信号を、前記超音波受信センサにより受信し、
前記(D)において、受信信号を周波数解析して、さらに高周波域の時間波形の振幅値を取得し、
前記(E)において、前記応力除荷時における前記低周波域及び前記高周波域の前記振幅値が、負荷応力の増加につれて低下する場合に、前記試験片の損傷有りと評価する。
In (C), when the stress is unloaded, the pseudo AE signal is transmitted from the ultrasonic oscillation source, and the pseudo AE signal propagated through the test piece is received by the ultrasonic receiving sensor.
In (D), the received signal is subjected to frequency analysis, and the amplitude value of the time waveform in the high frequency region is obtained,
In (E), when the amplitude values in the low frequency range and the high frequency range at the time of stress unloading decrease as the load stress increases, it is evaluated that the test piece is damaged.

前記制御解析装置は、前記受信信号を周波数解析して、さらに高周波域の時間波形の振幅値を取得し、前記振幅値の変化から、前記試験片の損傷の有無を評価する。
The control analysis device frequency-analyzes the received signal, further acquires an amplitude value of a time waveform in a high frequency region, and evaluates whether the test piece is damaged from the change in the amplitude value.

Claims (10)

(A)超音波発振源と超音波受信センサを複合材料からなる試験片に間隔を隔てて取り付け、
(B)引張荷重を順に増加させて、前記試験片に応力負荷と応力除荷を繰り返し、
(C)応力負荷時に、前記超音波発振源から疑似AE信号を発信し、前記試験片を伝搬した前記疑似AE信号を、前記超音波受信センサにより受信し、
(D)受信信号を周波数解析して、低周波域の時間波形の振幅値を取得し、
(E)前記振幅値の変化から、前記試験片の損傷の有無を評価する、複合材料の損傷評価方法。
(A) An ultrasonic oscillation source and an ultrasonic reception sensor are attached to a test piece made of a composite material at an interval,
(B) Increase the tensile load in order and repeat the stress load and stress unload on the test piece,
(C) At the time of stress loading, a pseudo AE signal is transmitted from the ultrasonic oscillation source, and the pseudo AE signal propagated through the test piece is received by the ultrasonic reception sensor,
(D) Analyzing the frequency of the received signal to obtain the amplitude value of the time waveform in the low frequency range,
(E) A damage evaluation method for a composite material, wherein the presence or absence of damage to the test piece is evaluated from the change in the amplitude value.
前記(E)において、前記応力負荷時における前記低周波域の前記振幅値が、負荷応力の増加につれて減少から増加に変化する場合に、その変化点の前記負荷応力を前記試験片の引張強度と評価する、請求項1に記載の複合材料の損傷評価方法。   In (E), when the amplitude value of the low frequency region at the time of the stress load changes from decrease to increase as the load stress increases, the load stress at the change point is set as the tensile strength of the test piece. The damage evaluation method for a composite material according to claim 1, which is evaluated. 前記(E)において、前記応力負荷時における前記低周波域の前記振幅値が、負荷応力の増加につれて減少する場合に、前記試験片の損傷なしと評価し、増加する場合に、前記試験片の損傷有りと評価する、請求項1に記載の複合材料の損傷評価方法。   In (E), when the amplitude value of the low frequency region at the time of the stress load decreases as the load stress increases, it is evaluated that the test piece is not damaged. The composite material damage evaluation method according to claim 1, wherein the composite material is evaluated as damaged. 前記(C)において、さらに応力除荷時に、前記超音波発振源から前記疑似AE信号を発信し、前記試験片を伝搬した前記疑似AE信号を、前記超音波受信センサにより受信し、
前記(D)において、受信信号を周波数解析して、さらに高周波域の時間波形の前記振幅値を取得し、
前記(E)において、前記応力除荷時における前記低周波域及び前記高周波域の前記振幅値が、負荷応力の増加につれて低下する場合に、前記試験片の損傷有りと評価する、請求項1に記載の複合材料の損傷評価方法。
In (C), when the stress is unloaded, the pseudo AE signal is transmitted from the ultrasonic oscillation source, and the pseudo AE signal propagated through the test piece is received by the ultrasonic receiving sensor.
In (D), the received signal is subjected to frequency analysis, and the amplitude value of the time waveform in the high frequency region is obtained,
In (E), when the amplitude values of the low frequency region and the high frequency region at the time of stress unloading decrease as the load stress increases, it is evaluated that the test piece is damaged. The damage evaluation method of the described composite material.
前記超音波発振源と前記超音波受信センサは、AEセンサである、請求項1に記載の複合材料の損傷評価方法。   The damage evaluation method for a composite material according to claim 1, wherein the ultrasonic oscillation source and the ultrasonic reception sensor are AE sensors. 最初の応力負荷前に、前記超音波発振源から発信される前記疑似AE信号を周波数解析して、その重心周波数又はその近傍を境にして、その下方を前記低周波域に、その上方を高周波域に設定する、請求項1に記載の複合材料の損傷評価方法。   Before the first stress load, the pseudo AE signal transmitted from the ultrasonic oscillation source is subjected to frequency analysis, with the center of gravity frequency or the vicinity thereof as a boundary, the lower part is the low frequency region, and the upper part is the high frequency part. The damage evaluation method for a composite material according to claim 1, wherein the damage evaluation method is set to a region. 前記低周波域は、0〜150kHzであり、前記高周波域は、150〜850kHzである、請求項6に記載の複合材料の損傷評価方法。   The damage evaluation method for a composite material according to claim 6, wherein the low frequency range is 0 to 150 kHz, and the high frequency range is 150 to 850 kHz. 複合材料からなる試験片に間隔を隔てて取り付けられる超音波発振源及び超音波受信センサと、
引張荷重を順に増加させて、前記試験片に応力負荷と応力除荷を繰り返す引張試験装置と、
応力負荷時に、前記超音波発振源から疑似AE信号を発信し、前記試験片を伝搬した前記疑似AE信号を、前記超音波受信センサにより受信するAE装置と、
受信信号を周波数解析して、低周波域の時間波形の振幅値を取得し、前記振幅値の変化から、前記試験片の損傷の有無を評価する制御解析装置と、を備えた複合材料の損傷評価装置。
An ultrasonic oscillation source and an ultrasonic reception sensor attached to a test piece made of a composite material at an interval;
A tensile test device that increases the tensile load in order and repeats stress loading and unloading on the test piece,
An AE device that transmits a pseudo AE signal from the ultrasonic oscillation source during stress loading and receives the pseudo AE signal propagated through the test piece by the ultrasonic reception sensor;
Frequency analysis of received signal to obtain amplitude value of time waveform in low frequency range, and control analysis device for evaluating presence or absence of damage of test specimen from change of amplitude value, damage to composite material Evaluation device.
前記AE装置は、さらに応力除荷時に、前記超音波発振源から前記疑似AE信号を発信し、前記試験片を伝搬した前記疑似AE信号を、前記超音波受信センサにより受信する、請求項8に記載の複合材料の損傷評価装置。   The said AE apparatus further transmits the said pseudo AE signal from the said ultrasonic oscillation source at the time of stress unloading, and receives the said pseudo AE signal which propagated the said test piece by the said ultrasonic reception sensor. The composite material damage evaluation apparatus described. 前記制御解析装置は、前記受信信号を周波数解析して、さらに高周波域の時間波形の前記振幅値を取得し、前記振幅値の変化から、前記試験片の損傷の有無を評価する、請求項8に記載の複合材料の損傷評価装置。   The control analysis apparatus performs frequency analysis on the received signal, obtains the amplitude value of a time waveform in a higher frequency region, and evaluates whether or not the test piece is damaged from the change in the amplitude value. The damage evaluation apparatus for composite materials described in 1.
JP2016052030A 2016-03-16 2016-03-16 Damage evaluation method and apparatus for composite materials Active JP6165908B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2016052030A JP6165908B1 (en) 2016-03-16 2016-03-16 Damage evaluation method and apparatus for composite materials

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2016052030A JP6165908B1 (en) 2016-03-16 2016-03-16 Damage evaluation method and apparatus for composite materials

Publications (2)

Publication Number Publication Date
JP6165908B1 JP6165908B1 (en) 2017-07-19
JP2017166953A true JP2017166953A (en) 2017-09-21

Family

ID=59351272

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2016052030A Active JP6165908B1 (en) 2016-03-16 2016-03-16 Damage evaluation method and apparatus for composite materials

Country Status (1)

Country Link
JP (1) JP6165908B1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020170360A1 (en) * 2019-02-20 2020-08-27 株式会社Ihi検査計測 Strength inspection method and strength inspection device
WO2020170359A1 (en) * 2019-02-20 2020-08-27 株式会社Ihi検査計測 Device and method for evaluating soundness of fiber-reinforced composite material
EP3779400A4 (en) * 2018-03-26 2021-04-28 IHI Inspection and Instrumentation Co., Ltd. Strength testing method and strength evaluation device
KR102362577B1 (en) * 2020-10-08 2022-03-17 부경대학교 산학협력단 Apparatus for analyzing dynamic characteristics of carbon fiber reinforced materials considering temperature, fiber direction and external loading pattern, and dynamic characteristics analyzing method using the same

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109374870B (en) * 2018-12-27 2024-03-29 中交武汉港湾工程设计研究院有限公司 Method and device for evaluating repairing performance of cement-based self-repairing material

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04299233A (en) * 1991-03-28 1992-10-22 Nippon Steel Corp Method of detecting crack in metal material in repeated bending test of the metal material or the like
JPH1090235A (en) * 1996-09-13 1998-04-10 Nippon Cement Co Ltd Method of judging deterioration of concrete structure
JPH11352042A (en) * 1998-06-11 1999-12-24 Agency Of Ind Science & Technol Method for diagnosing degree of damage to base rock
JP2014142273A (en) * 2013-01-24 2014-08-07 Ihi Inspection & Instrumentation Co Ltd Strength inspection method and data output device for strength evaluation

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04299233A (en) * 1991-03-28 1992-10-22 Nippon Steel Corp Method of detecting crack in metal material in repeated bending test of the metal material or the like
JPH1090235A (en) * 1996-09-13 1998-04-10 Nippon Cement Co Ltd Method of judging deterioration of concrete structure
JPH11352042A (en) * 1998-06-11 1999-12-24 Agency Of Ind Science & Technol Method for diagnosing degree of damage to base rock
JP2014142273A (en) * 2013-01-24 2014-08-07 Ihi Inspection & Instrumentation Co Ltd Strength inspection method and data output device for strength evaluation

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3779400A4 (en) * 2018-03-26 2021-04-28 IHI Inspection and Instrumentation Co., Ltd. Strength testing method and strength evaluation device
US11680879B2 (en) 2018-03-26 2023-06-20 Ihi Inspection And Instrumentation Co., Ltd. Strength testing method and strength evaluation device
WO2020170360A1 (en) * 2019-02-20 2020-08-27 株式会社Ihi検査計測 Strength inspection method and strength inspection device
WO2020170359A1 (en) * 2019-02-20 2020-08-27 株式会社Ihi検査計測 Device and method for evaluating soundness of fiber-reinforced composite material
JPWO2020170359A1 (en) * 2019-02-20 2021-12-23 株式会社Ihi検査計測 Soundness evaluation device and method for fiber reinforced composite materials
JP7166426B2 (en) 2019-02-20 2022-11-07 株式会社Ihi検査計測 Apparatus and method for evaluating soundness of fiber-reinforced composite material
KR102362577B1 (en) * 2020-10-08 2022-03-17 부경대학교 산학협력단 Apparatus for analyzing dynamic characteristics of carbon fiber reinforced materials considering temperature, fiber direction and external loading pattern, and dynamic characteristics analyzing method using the same

Also Published As

Publication number Publication date
JP6165908B1 (en) 2017-07-19

Similar Documents

Publication Publication Date Title
JP6165908B1 (en) Damage evaluation method and apparatus for composite materials
EP3070467B1 (en) Ultrasonic test system, ultrasonic test method and method of manufacturing aircraft part
US7546769B2 (en) Ultrasonic inspection system and method
US10180410B2 (en) Ultrasonic test system, ultrasonic test method and aircraft structural object
CN104407054A (en) Ultrasonic micro-damage location detection method and device based on collinear aliasing of Lamb waves
JP7243983B2 (en) Non-contact acoustic analysis system
JP2012141230A (en) Nondestructive testing system
JP5841081B2 (en) Strength inspection method and strength evaluation data output device
KR20100060257A (en) Method and apparatus for damage diagnosis of coatings by acoustic emission technique
US11226312B1 (en) In-process, layer-by-layer non-destructive testing of additive manufactured components using linear and nonlinear vibrational resonance
JP2010019622A (en) Ultrasonic flaw detection method and device
JP2005148064A (en) Device and method for detecting change or damage to pressure vessel during or after pressure test
US20150089792A1 (en) Acoustic testing of sapphire components for electronic devices
Dostál et al. Visualisation of corrosion acoustic signals using quality tools
JP6598045B2 (en) Ultrasonic inspection method
KR101877769B1 (en) Apparatus for hybrid multi-frequency ultrasound phased array imaging
JP6710653B2 (en) Sensor adhesion state determination system, sensor adhesion state determination device, and sensor adhesion state determination method
RU2461820C1 (en) Method of determining strength characteristics of polymer composite materials
JP2020041814A (en) Detection system, detection method, and server device
CN105651857A (en) Dynamic real-time monitoring method of airplane plate hole connection structure fatigue damage
US10794867B2 (en) System and method of diagnosing tube sensor integrity by analysis of excited stress waves
JP5841027B2 (en) Inspection apparatus and inspection method
EP2869068A1 (en) Method for ultrasonic testing of bolted and riveted joints in structures
RU2640956C1 (en) Device of ultrasonic controlling state of products
JP2015021749A (en) Inspection device and inspection method

Legal Events

Date Code Title Description
A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20170511

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20170609

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20170621

R150 Certificate of patent or registration of utility model

Ref document number: 6165908

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250