JPS5814047A - Detection of cracks in test pieces - Google Patents
Detection of cracks in test piecesInfo
- Publication number
- JPS5814047A JPS5814047A JP11312581A JP11312581A JPS5814047A JP S5814047 A JPS5814047 A JP S5814047A JP 11312581 A JP11312581 A JP 11312581A JP 11312581 A JP11312581 A JP 11312581A JP S5814047 A JPS5814047 A JP S5814047A
- Authority
- JP
- Japan
- Prior art keywords
- test piece
- crack
- potential difference
- distance
- lead wire
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/20—Investigating the presence of flaws
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は材料試験における試験片の亀裂検出方法に係シ
、特に電気ポテンシャル法の改善に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting cracks in specimens in materials testing, and more particularly to improvements in the electric potential method.
一般に金属材料等の強度を試験する材料試験において、
繰返し荷重等全試験片に加えて発生する亀裂の検出方法
の一つに電気ポテンシャル法力する０
第１図は従来の電気ポテンシャル法を示すもので、図示
しない材料試験機の上下プルロッド１゜２には、切欠き
３を有する試験片４が絶縁把持されておシ、この試験片
４には、リード＃５，５を介して電源６が、また亀裂電
位差検出用リード線７，７を介して増幅器８がそれぞれ
接続されている。そして増幅器８の出力側には六示器９
が接続されている。Generally, in material tests that test the strength of metal materials, etc.
One method for detecting cracks that occur in all test specimens due to repeated loading is the electric potential method. Figure 1 shows the conventional electric potential method. In this case, a test piece 4 having a notch 3 is held insulated, and a power source 6 is connected to this test piece 4 through leads #5, 5, and a power source 6 is connected to the test piece 4 through lead wires 7, 7 for detecting crack potential difference. Amplifiers 8 are connected to each. And on the output side of the amplifier 8 there is a six indicator 9.
is connected.
以上の構成において亀裂長さの検出に際しては、まずリ
ードａ５を介して試験片４の軸方向に定電流（定電圧）
を印加するとともｌこ、上下プルロッド１，２によｐ試
験片４に矢印方向の繰返し荷重を加える。そして切欠ｔ
８３に亀裂が発生すると。In the above configuration, when detecting the crack length, first, a constant current (constant voltage) is applied to the axial direction of the test piece 4 via the lead a5.
At the same time, a repeated load is applied to the test piece 4 in the direction of the arrow by the upper and lower pull rods 1 and 2. and notch t
When a crack occurs in 83.
増幅器８にはこの亀裂電位差信号が入力され、さらに表
示器９の指示によｊ）８２図に示す亀裂長さ対電位差出
力の特性曲線が得られる。This crack potential difference signal is input to the amplifier 8, and further, according to instructions from the display 9, a characteristic curve of the crack length versus potential difference output shown in FIG. 82 is obtained.
ところで、第２図１こ示す特性曲線は一般に非線形をな
しておシ、また電位差出力は試験片の材質。By the way, the characteristic curve shown in FIG. 2 is generally nonlinear, and the potential difference output depends on the material of the test piece.
形状、雰囲気温度および電源変動に影響される。Affected by shape, ambient temperature, and power supply fluctuations.
このため、従来の検出方法ではそれぞれの較正および定
電流（定電圧）化が必要で６つ友。For this reason, conventional detection methods require calibration and constant current (constant voltage) for each.
本発明の目的は、試験片の材質、形状または算囲気温贋
の較正が不要で定電流（定電圧）化の必要もない試験片
の亀裂検出方法を提供するにある。An object of the present invention is to provide a method for detecting cracks in a test piece that does not require calibration of the material, shape, or calculated ambient temperature of the test piece, and does not require constant current (constant voltage).
本発明の他の目的は、検出出力から亀裂長さを直読でき
る試験片の亀裂検出方法を提供するにある。Another object of the present invention is to provide a method for detecting cracks in a test piece that allows the length of cracks to be directly read from the detection output.
以下、本発明の実施例を図面を参照して説明する。Embodiments of the present invention will be described below with reference to the drawings.
第３図−こおいて番号１．２は、図示しない材料試験機
の上下プルロッドであシ、このプルロッド１．２には、
切欠き３を有する試験片４がピン１０を介して取付けら
れている。この試験片４の前記切欠き３を介してその上
下位置には、通電用のリード線５，５および亀裂電位差
検出用リードＭ７゜７が所要の通電距離および亀裂検出
距離をそれぞれ有して取付けられてお夛リードｌＩ！１
５には電源６が、またリード線７には増幅器８がそれぞ
れ接続されている。前記リード線５にはまた、増幅器１
１が接続され、この増幅器１１からの出力は前記増幅器
８からの出力とともに′ａ算器１２に入力されて演算さ
れ、その結果が表示器９に入力されるよりになっている
。Figure 3 - In this figure, number 1.2 is the upper and lower pull rods of the material testing machine (not shown), and this pull rod 1.2 has the following:
A test piece 4 having a notch 3 is attached via a pin 10. Lead wires 5, 5 for energization and leads M7゜7 for crack potential difference detection are attached to the upper and lower positions of the test piece 4 through the notch 3 with the required energization distance and crack detection distance, respectively. It’s time to lead! 1
5 is connected to a power source 6, and the lead wire 7 is connected to an amplifier 8. The lead wire 5 also includes an amplifier 1.
1 is connected, and the output from this amplifier 11 is input to the 'a calculator 12 together with the output from the amplifier 8 for calculation, and the result is input to the display 9.
ここで、試験片４においてリード線７．７間の切欠ｔ！
、３における亀裂抵抗をｒ、’）−ド線５，５間の試験
片抵抗をＲとすると。Here, in the test piece 4, the notch t! between the lead wires 7 and 7!
, 3 is r, and the test piece resistance between the wires 5 and 5 is R.
但し、ρ：固有抵抗
ｉ！１：リード線７．７間の距離
（亀裂検出距離）
１２：リード線５．５間の距離
（通電距離）
Ｂ：試験片４の断面積
となシ、両抵抗ｒ、Ｒは距離および断面積ｌζ関連して
いる。そして試験片４に第３図に示す矢印方向の繰返し
荷重を加えると、切欠き３からの亀裂の発生進展に伴な
い、抵抗ｒ、Ｒは第４図に示すように一方は大きく他方
は小さく変化する特性曲線となる。However, ρ: specific resistance i! 1: Distance between lead wires 7.7 (crack detection distance) 12: Distance between lead wires 5.5 (current carrying distance) B: Cross-sectional area of test piece 4 and R, both resistances r and R The area lζ is related. When a repeated load is applied to the test piece 4 in the direction of the arrow shown in Fig. 3, as a crack develops from the notch 3, the resistances r and R become larger on one side and smaller on the other as shown in Fig. 4. This results in a changing characteristic curve.
また、増幅器８，１１の増幅度をそれぞれ人、Ｂとする
と、各増幅器８．１１の出力電圧は、計測電圧ＡｒＩ・
・・増幅器８の出力電圧比較電圧ＢＲＩ・・増幅器１１
の出力電圧但し Ｉ：＊源６から試験片４に印加
される電流
として表わすことができる。そしてこれらの出力電圧は
割算器１２に入力されて（３）式の演算がなされ、両軍
圧の比が求められる。Further, if the amplification degrees of the amplifiers 8 and 11 are expressed as B and B, respectively, the output voltage of each amplifier 8 and 11 is the measured voltage ArI.
...Output voltage comparison voltage BRI of amplifier 8...Amplifier 11
The output voltage of where I: *can be expressed as the current applied from the source 6 to the test piece 4. These output voltages are then input to the divider 12, where the calculation of equation (3) is performed, and the ratio between the two military pressures is determined.
、この（３）式において、試験片４の初期状態（亀裂長
さＪ ＝ １０ における抵抗Ｒ＝Ｒ，）、ｒ＝ｒ＠
）の電圧比が１になるように増幅度Ａ、Ｂをそれぞれ調
整すると。, In this equation (3), the initial state of the test piece 4 (resistance R=R at crack length J = 10), r=r@
) by adjusting the amplification degrees A and B so that the voltage ratio becomes 1.
よシ。Yosi.
となる。この（６）式は試験片４に通電される電流Ｉに
依存しないのでこの電流■の変動に影響されず、したが
って電源６を定ｖｔ流（定電圧）源とする必要がない。becomes. Since this equation (6) does not depend on the current I applied to the test piece 4, it is not affected by fluctuations in the current (2), and therefore there is no need to use the power source 6 as a constant VT current (constant voltage) source.
このため、試験片４への強度影響のない低電流等任意の
電流を与えることが可能となる。Therefore, it is possible to apply any current such as a low current that does not affect the strength of the test piece 4.
また、計測電圧ＡｒＩおよび比較電圧ＢＲＩは、いずれ
も試験片４から検出されるので、 ４゜、／Ｒ。Furthermore, since both the measurement voltage ArI and the comparison voltage BRI are detected from the test piece 4, 4°,/R.
状あるいは雰囲気温度に影響されない。したがってこれ
らを較正することなく表示器９の表示値からそのまま亀
裂長さを求めることが可能となる。unaffected by environmental conditions or ambient temperature. Therefore, it is possible to directly determine the crack length from the values displayed on the display 9 without calibrating them.
しかして、計測電圧と比較電圧との電圧比を用いること
によシ、試験片の材質、形状または雰囲気温度の較正が
不要とな夛、また定電流（定電圧）化の必要もない。By using the voltage ratio between the measurement voltage and the comparison voltage, there is no need to calibrate the material, shape, or ambient temperature of the test piece, and there is no need for constant current (constant voltage).
ところで、前記試験片４における亀裂抵抗ｒおよび試験
片抵抗Ｒの亀裂進展に伴なう抵抗変化は、第４図からも
明らかなようｌこ非線形をなすのが通例である。このた
め、亀裂長さｌと抵抗比 ｒ／ｒ、。By the way, as is clear from FIG. 4, the crack resistance r and the resistance change of the test piece resistance R in the test piece 4 as the crack progresses are usually non-linear. Therefore, the crack length l and the resistance ratio r/r,.
Ｒ／Ｒｏとの関係も第５図に示すように線形と鉱ならな
い。The relationship with R/Ro is also linear as shown in FIG.
しかし、これらの抵抗比 ／、／ は、前記ｒｏ
ｋＱ
（１） 、 （２）式から導びかれるようにリード線７
．７および５，５の試験片４取付距離、すなわち亀裂検
出距離および通電距離のみの関数でｈｖ、したがってこ
れらの距離を適当に設定することによシ、定範囲（第６
図ζこおりてｌ。からａまでの範囲）ζこおいて線形と
することが可能となる。そしてこれζこよシ、表示器９
の指示値から亀裂長さｌを直読することが可能となる。However, these resistance ratios /, / are
kQ As derived from equations (1) and (2), the lead wire 7
．． hv is a function of only the installation distance of test piece 4 of 7 and 5, 5, that is, the crack detection distance and the current conduction distance.Therefore, by appropriately setting these distances, it is possible to
Figure ζ Koorete l. It is possible to make it linear in the range from ζ to a). And this is ζkoyoshi, display 9
It becomes possible to directly read the crack length l from the indicated value.
しかして、亀裂検出距離および通電距離を適当に設定す
ることによシ、検出値から亀裂長さを直読することがで
きる。By appropriately setting the crack detection distance and the energization distance, the crack length can be directly read from the detected value.
以上説明したように本発明は、亀裂電位差の増幅出力と
１通電距離にυける試験片抵抗および通電電流から求め
られる試験片電位の増１隔出力との割算比を求め、その
１直から亀裂長さを測定するので、試験片の材質、形状
′または雰囲気温度の較正が不要となシ、定電流（定電
圧）化の必要もない。As explained above, the present invention calculates the division ratio of the amplified output of the crack potential difference and the increased output of the test piece potential obtained from the test piece resistance and the applied current over one energizing distance, and from that one turn. Since the crack length is measured, there is no need to calibrate the material, shape or ambient temperature of the test piece, and there is no need for constant current (constant voltage).
また、前記割算比が線形゛をなすように亀裂検出距離お
よび通電距離をそれぞれ設定し、線形をなす割算比の値
から亀裂長さを測定するので、検出値から亀裂長さを直
読することができる。In addition, the crack detection distance and energization distance are each set so that the division ratio is linear, and the crack length is measured from the linear division ratio value, so the crack length can be directly read from the detected value. be able to.
第１図は従来の電気ポテンシャル法を示す説明図、第２
図は従来の′亀裂長さ対電位差出力の特性図、第３図は
本発明の実施例を示す説明図、第４図および第５図は亀
裂長さ対亀裂抵抗、試験片抵抗の特性図、第６図は亀裂
長さ対割算器出力の特性図である。
３・・・切欠き、４・・・試験片、５・・・通電相リー
ド線。
７・・・亀裂電位差検出用リード線、８，１１・・増幅
器、９・・・表示器、１２・・・割算器。
出願人代理人 猪 股 清第１図
□１裟炙こ
第３図
４
第４図
１０ □龜鼠臭さｔ
第５図
第６図
（。 □・龜袈畏之［
２５２−Figure 1 is an explanatory diagram showing the conventional electric potential method, Figure 2
The figure is a conventional characteristic diagram of crack length versus potential difference output, Figure 3 is an explanatory diagram showing an embodiment of the present invention, and Figures 4 and 5 are characteristic diagrams of crack length versus crack resistance and test piece resistance. , FIG. 6 is a characteristic diagram of crack length versus divider output. 3... Notch, 4... Test piece, 5... Current-carrying phase lead wire. 7... Lead wire for crack potential difference detection, 8, 11... Amplifier, 9... Display, 12... Divider. Applicant's agent Kiyoshi Inomata Figure 1 □ 1 Roasted Figure 3 Figure 4 Figure 4 10 □ The odor of a rat Figure 5 Figure 6 (.
Claims (1)
よび亀裂電位差検出用リード線をそれぞれ接続するとと
もに、この試験片１こ繰返し荷重を加え、亀裂電位差検
出用リード線を介して検出される亀裂電位差出力から亀
裂長さを求めるものにおいて、前記亀裂電位差の増幅出
力と１通電距離における試験片抵抗および通電電流から
求められる試験片電位の増幅出力との割算比を求め、そ
の値から亀裂長さを測定することを特徴とする試験片の
亀裂検出方法。 ２、試験片に設けた切欠きの両側に通電用リード線およ
び亀裂電位差検出用リード線をそれぞれ接続するととも
に、この試験片に繰返し荷重を加え、亀裂電位差検出用
リード線を介して検出される亀裂電位差出力から亀裂長
さを求めるものにおいて、前記亀裂電位差の増幅出力と
、通電距離における試験片抵抗および通電電流から求め
られる試験片電位の増幅出力との割算比を求めるととも
に、この割算比が線形をなすように亀裂検出距離および
通電距離をそれぞれ設定し、線形をなす割算比の値から
亀裂長さを測定することを特徴とする試験片の亀裂検出
方法。[Scope of Claims] 1. Connect the current-carrying lead wire and the crack potential difference detection lead wire to each side of the notch provided in the test piece, and apply a repeated load to the test piece to detect the crack potential difference. In determining the crack length from the output of the crack potential difference detected through the lead wire, divide the amplified output of the crack potential difference and the amplified output of the test piece potential determined from the test piece resistance and the energized current at one energizing distance. A method for detecting cracks in a test piece, characterized by determining the ratio and measuring the crack length from that value. 2. Connect current-carrying lead wires and crack potential difference detection lead wires to both sides of the notch provided in the test piece, apply repeated loads to this test piece, and detect crack potential difference detection via the crack potential difference detection lead wires. In determining the crack length from the output of the crack potential difference, find the division ratio between the amplified output of the crack potential difference and the amplified output of the test piece potential determined from the test piece resistance at the energizing distance and the energized current, and also calculate the division ratio. A method for detecting cracks in a test piece, characterized in that a crack detection distance and an energization distance are each set so that the ratio is linear, and the crack length is measured from the value of the linear division ratio.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11312581A JPS5814047A (en) | 1981-07-20 | 1981-07-20 | Detection of cracks in test pieces |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11312581A JPS5814047A (en) | 1981-07-20 | 1981-07-20 | Detection of cracks in test pieces |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS5814047A true JPS5814047A (en) | 1983-01-26 |
Family
ID=14604158
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11312581A Pending JPS5814047A (en) | 1981-07-20 | 1981-07-20 | Detection of cracks in test pieces |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5814047A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007003436A (en) * | 2005-06-27 | 2007-01-11 | Tokyo Electric Power Co Inc:The | Sensor for crack depth measuring device and crack depth measuring device |
-
1981
- 1981-07-20 JP JP11312581A patent/JPS5814047A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007003436A (en) * | 2005-06-27 | 2007-01-11 | Tokyo Electric Power Co Inc:The | Sensor for crack depth measuring device and crack depth measuring device |
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