JPH03176627A - Estimating method for stress of depressed pipe - Google Patents
Estimating method for stress of depressed pipeInfo
- Publication number
- JPH03176627A JPH03176627A JP31417389A JP31417389A JPH03176627A JP H03176627 A JPH03176627 A JP H03176627A JP 31417389 A JP31417389 A JP 31417389A JP 31417389 A JP31417389 A JP 31417389A JP H03176627 A JPH03176627 A JP H03176627A
- Authority
- JP
- Japan
- Prior art keywords
- stress
- pipe
- curve
- magnetostrictive sensor
- value
- 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
Links
- 238000000034 method Methods 0.000 title claims description 27
- 230000000994 depressogenic effect Effects 0.000 title abstract 3
- 239000000463 material Substances 0.000 claims abstract description 25
- 230000002093 peripheral effect Effects 0.000 abstract description 6
- 230000000881 depressing effect Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 23
- 238000005259 measurement Methods 0.000 description 17
- 238000000691 measurement method Methods 0.000 description 6
- 238000001514 detection method Methods 0.000 description 5
- 230000005284 excitation Effects 0.000 description 5
- 238000011088 calibration curve Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000035699 permeability Effects 0.000 description 4
- 238000005452 bending Methods 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、例えばパイプラインを橋台背面部等でループ
配管を行う場合に、その曲管部と直管部との溶接部近傍
に応力が集中するので、この曲管部近傍の直管部に生じ
る偏平化に伴う応力を、磁歪センサの測定値より推定す
る管の偏平応力推定方法に関するものである。[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to the case where, for example, loop piping is carried out at the back of an abutment of a pipeline, and stress is generated near the weld between the curved pipe section and the straight pipe section. This invention relates to a method for estimating flattening stress in a tube, in which the stress caused by flattening that occurs in a straight pipe section near the curved tube section is estimated from the measured value of a magnetostrictive sensor.
［従来の技術］
鋼材又は鋼製構造物等の応力及び残留応力を測定する方
性として、Ｘ線や超音波のほかに磁歪センサによる方法
がある。この磁歪センサを用いて磁化可能な丸棒、パイ
プ等円柱材料の応力を測定する方法としては先に出願し
た特願昭６３−１５３６２２号公報に示された磁歪応力
測定法がある。[Prior Art] In addition to X-rays and ultrasonic waves, there are methods using magnetostrictive sensors to measure stress and residual stress in steel materials or steel structures. As a method for measuring the stress of magnetizable cylindrical materials such as round rods and pipes using this magnetostrictive sensor, there is a magnetostrictive stress measuring method disclosed in Japanese Patent Application No. 153622/1988, which was previously filed.
磁歪応力測定法は、磁性材料に荷重が作用すると透磁率
に異方性が生じ、荷重方向の透磁率が大きくなり、反対
に荷重方向と直角方向の透磁率が小さくなるので、両道
磁率の差を励磁コイルと検出コイルを持つ磁歪センサ（
磁気異方性センサともいう）によって検出することによ
り、主応力の方向および大きさを測定する方法である。In the magnetostrictive stress measurement method, when a load is applied to a magnetic material, anisotropy occurs in the magnetic permeability, and the permeability in the direction of the load increases, while the permeability in the direction perpendicular to the direction of the load decreases, so the difference in magnetic permeability in both directions is measured. A magnetostrictive sensor with an excitation coil and a detection coil (
This method measures the direction and magnitude of principal stress by detecting it with a magnetic anisotropy sensor (also called a magnetic anisotropy sensor).
この測定方法によると、−１点の測定時間がｌＯ〜１０
０ａ＋ｓｅｃですみ、取扱いもきわめて便宜である。According to this measurement method, the measurement time for -1 point is lO~10
It only takes 0a+sec and is extremely convenient to handle.
ところが、従来の磁歪応力測定法は、一般に磁歪センサ
を被測定面に接触させて行うものであるため、被測定面
の状態によって接触面における磁気抵抗が大きく異なる
。そのため、測定誤差が大きくなるという欠点があった
。However, since conventional magnetostrictive stress measurement methods are generally performed by bringing a magnetostrictive sensor into contact with a surface to be measured, the magnetic resistance at the contact surface varies greatly depending on the state of the surface to be measured. Therefore, there was a drawback that the measurement error became large.
そこで、非接触状態、すなわち磁歪センサを被測定面か
ら一定の距離だけ離した状態で測定するという考え方が
出てくるわけであるが、この場合は磁歪感度が低下する
ため、磁歪センサの設定にありきわめて微妙な調整が必
要であるという別の問題があった。Therefore, the idea of measuring in a non-contact state, that is, with the magnetostrictive sensor a certain distance away from the surface to be measured, has come up, but in this case, the magnetostrictive sensitivity decreases, so the settings of the magnetostrictive sensor must be adjusted. There was another problem that required some very delicate adjustments.
前記先願の発明においては、前記非接触計測における問
題点を解決し、磁化可能な丸棒、パイプ等の円柱材料に
対する磁歪応力測定法を非接触方式で実施できる装置を
開発し、そのｍ定装置を使用して円柱材料の円周方向の
応力分布を従来よりも精度良く測定できる方法を提供し
た。In the invention of the earlier application, the problem in the non-contact measurement was solved, and an apparatus was developed that could perform the magnetostrictive stress measurement method on cylindrical materials such as magnetizable round bars and pipes in a non-contact manner, and the m-determination method was developed. We have provided a method that uses a device to measure the stress distribution in the circumferential direction of a cylindrical material with higher accuracy than before.
第１図は先の出願に係る磁歪応力測定法を説明する図で
あり、同図（ａ）は円柱材料１に曲げ荷重を加えて、円
柱材料１の上側に引張り応力＋σ、下側に圧縮応力−σ
が働いている状態を示す。また同図（ｂ）は円柱材料１
の中心軸に対して垂直に、且つその外周面と一定の距ｉ
りＩｈのリフト・オフ（ギャップのこと）を保ちながら
、磁歪センサ２を円柱材料１の最上点即ちＯ″の角度位
置より時計廻り方向に円周方向に沿って１回転させて、
磁歪センサ２がＯ″〜３６０ ”間のそれぞれの角度位
置において検出する磁歪信号を連続的に測定する方法を
示している。FIG. 1 is a diagram explaining the magnetostrictive stress measurement method according to the previous application, and FIG. Stress - σ
indicates that it is working. In addition, the same figure (b) shows the cylindrical material 1.
perpendicular to the central axis of and at a certain distance i from the outer peripheral surface of
While maintaining the lift-off (gap) of Ih, rotate the magnetostrictive sensor 2 once along the circumferential direction in a clockwise direction from the uppermost point of the cylindrical material 1, that is, the angular position O''.
This figure shows a method of continuously measuring magnetostrictive signals detected by the magnetostrictive sensor 2 at each angular position between 0'' and 360''.
第２図は第１図の磁歪応力１Ｎ−１定法によるＳＩＮ近
似法を説明する図であり、同図（ａ）は磁歪センサ２が
円柱材料１の外周上の方位を示す角度とその応力分布を
示し、角度０″ （即ち円柱材料１の真上）において最
大引張り応力が、角度１８０ ’（即ち円柱材料１の真
下）において最大圧縮応力が発生することから、応力分
布はＳＩＮθ曲線に近似して分布する。FIG. 2 is a diagram for explaining the SIN approximation method using the magnetostrictive stress 1N-1 regular method in FIG. Since the maximum tensile stress occurs at an angle of 0'' (i.e. directly above the cylindrical material 1) and the maximum compressive stress occurs at an angle of 180' (i.e. directly below the cylindrical material 1), the stress distribution approximates a SINθ curve. distribution.
第２図（ｂ）は−２０ｋｇ／−の荷重を円柱材料に加え
たときの、歪ゲージによる応力の実測値とＳＩＮθ近似
値とを示している。この図から実際の応力分布とＳＩＮ
θ曲線とはかなり近似していることが判る。FIG. 2(b) shows the actual value of stress measured by the strain gauge and the approximate value of SINθ when a load of -20 kg/- is applied to the cylindrical material. From this figure, the actual stress distribution and SIN
It can be seen that the curve is quite similar to the θ curve.
［発明が解決しようとする課題］
上記の特願昭６３−１５３６２２号公報に示された、管
材の磁歪応力測定法によるＳＩＮθ近似法においては、
管材直管部の曲げ応力測定には適しているが、管材曲管
部近傍の直管部では曲管部の偏平化に伴う影響があり、
直管部と言えども応力分布が管周方向の角度θに対して
きれいなＳＩＮ曲線とＤらない。従って管の曲管部近傍
の直管部においては、先に出願した５ＩＮｏ近似法が適
用できないという問題点があった。[Problems to be Solved by the Invention] In the SINθ approximation method using the magnetostrictive stress measurement method of pipe materials, which is shown in the above-mentioned Japanese Patent Application No. 153622/1982,
Although it is suitable for measuring bending stress in straight sections of pipe material, it is affected by the flattening of the bent section of straight pipes near the bent section of the pipe material.
Even though it is a straight pipe, the stress distribution does not form a clean SIN curve with respect to the angle θ in the circumferential direction of the pipe. Therefore, there was a problem in that the previously applied 5INo approximation method could not be applied to straight pipe sections near curved pipe sections.
第３図（ａ）は管が偏平したときの応力状態を示す図で
あり、同図（ａ）においては、管周方向の角度で０６と
１８０ ”の位置では圧縮応力−σが、９０°と２７０
°の位置では引張応力＋σが働いていることが示される
。Fig. 3(a) is a diagram showing the stress state when the pipe is flattened. In Fig. 3(a), the compressive stress -σ is 90° at the positions of 06 and 180'' in the circumferential direction of the pipe. and 270
It is shown that tensile stress +σ is acting at the position of °.
第３図（ｂ）は同図（ａ）の管の偏平応力状態における
磁歪センサ出力を示す図であり、横軸は磁歪センサを管
材の中心軸に対して垂直な管外周面上を時計廻りに１回
転させたときに、該センサの管周上の方位を示す角度で
ある。また縦軸は磁歪センサ出力（単位はボルト）であ
り、該センサの計測値が図中の十印で示される。FIG. 3(b) is a diagram showing the output of the magnetostrictive sensor when the tube shown in FIG. 3(a) is in a state of flattened stress. This is the angle that indicates the direction of the sensor on the pipe circumference when the sensor is rotated once. The vertical axis is the output of the magnetostrictive sensor (in volts), and the measured value of the sensor is indicated by the cross mark in the figure.
この第３図（ｂ）により管の曲管部近傍では、直管部と
いえどもＳＩＮθ近似法が適用でないという問題点が明
らかとなっている。FIG. 3(b) clearly shows the problem that the SINθ approximation method is not applicable near the curved portion of the pipe, even in the case of a straight pipe portion.
本発明はかかる問題点を解決するためになされたもので
、管材の曲管部近傍の直管部において計測された磁歪セ
ンサ出力に基づき、前記直管部に生じる偏平化に伴う応
力値を推定することができる管の偏平応力推定方法を得
ることを目的とする。The present invention has been made to solve this problem, and based on the magnetostrictive sensor output measured in the straight pipe section near the bent pipe section of the pipe material, the stress value due to the flattening that occurs in the straight pipe section is estimated. The purpose of this study is to obtain a method for estimating flattened stress in pipes.
［課題を解決するための手段］
この発明に係る管の偏平応力推定方法は、磁歪センサが
管材の外周面上または内周面上を非接触状態で相対移動
する測定装置を用いて、前記管材の管周方向の応力分布
をＳＩＮ曲線で近似して推定する方法において、管材曲
管部近傍の直管部において計測された磁歪センサ出力よ
りＳＩＮθ近似値を減算して得られた偏差値をＳＩＮ２
θ曲線により近似し、該近似した５ＩＮ２θ曲線の信号
振幅値より対応する前記直管部に生じる偏平化に伴う応
力値を推定する管の偏平応力推定手段を備えたものであ
る。[Means for Solving the Problems] A method for estimating flat stress in a pipe according to the present invention uses a measuring device in which a magnetostrictive sensor moves relatively on the outer peripheral surface or inner peripheral surface of the pipe material in a non-contact state. In the method of estimating the stress distribution in the tube circumferential direction by approximating it with a SIN curve, the deviation value obtained by subtracting the SINθ approximate value from the magnetostrictive sensor output measured in the straight pipe section near the curved section of the pipe material is calculated as SIN2.
The pipe is approximated by a θ curve and includes a tube flattening stress estimating means for estimating a stress value due to flattening occurring in the corresponding straight pipe portion from the signal amplitude value of the approximated 5IN2θ curve.
［作用コ
この発明においては、磁歪センサが管材の外周面上また
は内周面上を非接触状態で相対移動する測定装置を用い
て、前記管材の管周方向の応力分布をＳＩＮ曲線で近似
して推定する方法において、管の偏平応力推定手段によ
り管材曲管部近傍の直管部において計測された磁歪セン
サ出力よりＳＩＮθ近似値を減算して得られた偏差値を
ＳＩＮ２θ曲線により近似し、該近似したＳ ＩＮ２θ
曲線の信号振幅値より対応する前記直管部に生じる偏平
化に伴う応力値を推定する。[Operation] In this invention, the stress distribution in the circumferential direction of the tube is approximated by a SIN curve using a measuring device in which a magnetostrictive sensor moves relatively on the outer circumferential surface or the inner circumferential surface of the tube in a non-contact state. In this method, the deviation value obtained by subtracting the SINθ approximate value from the magnetostrictive sensor output measured in the straight pipe section near the bent pipe section by the tube flattening stress estimation means is approximated by the SIN2θ curve, and the deviation value obtained by subtracting the SINθ approximate value is Approximate S IN2θ
A stress value due to flattening occurring in the corresponding straight pipe portion is estimated from the signal amplitude value of the curve.
［実施例］
第４図は本発明の管の偏平応力推定方法を適用する管の
応力測定装置のブロック図である。図においてｌＯは走
行装置部であり、磁気異方性センサ１１及び走行台車１
２を内蔵する。磁気異方性センサ１１は非接触により管
材の円周方向の磁気異方性を検出するためのセンサであ
り、例えば直交する励磁コイ−ルと検出コイルとを備え
、励磁コイルに一定の励振電流を流して、応力の作用に
よって生じる磁気異方性を検出コイルから得られる電圧
信号として検出するものである。走行台車１２は例えば
管外周上に設けられたレール又は／及びギヤ上を走行し
、磁気異方性センサＩＩを管の円周方向に移動させ計測
を行わせるための走行機構である。ｉ３は磁歪測定部で
あり、磁気異方性センサ１１の励磁コイルに定電流を供
給し、同時に該センサ１ｔの検出コイルより得られる検
出信号を増幅し、磁気異方性に比例した電圧信号として
出力する磁歪測定部である。１４はモータ・ドライバで
あり、走行台車Ｉ２に走行駆動信号を供給し走行させ、
その走行結果の位置情報としてエンコーダ信号が帰還さ
れる。１５ハＡ／Ｄ変換器、１６は例えばＲ３２３２Ｃ
等のインタフェース、１７はパーソナル・コンピユー７
（以下パソコンという）、１８はＣＲＴ又は液晶等を用
いたデータ表示部である。[Example] FIG. 4 is a block diagram of a pipe stress measuring device to which the pipe flat stress estimation method of the present invention is applied. In the figure, lO is a traveling device section, which includes a magnetic anisotropy sensor 11 and a traveling trolley 1.
Built-in 2. The magnetic anisotropy sensor 11 is a sensor for detecting magnetic anisotropy in the circumferential direction of a tube material in a non-contact manner, and includes, for example, an excitation coil and a detection coil that are perpendicular to each other, and a constant excitation current is applied to the excitation coil. is applied, and the magnetic anisotropy caused by the action of stress is detected as a voltage signal obtained from the detection coil. The traveling trolley 12 is a traveling mechanism that travels, for example, on rails and/or gears provided on the outer periphery of the tube, and moves the magnetic anisotropy sensor II in the circumferential direction of the tube to perform measurements. i3 is a magnetostriction measurement unit that supplies a constant current to the excitation coil of the magnetic anisotropy sensor 11, and at the same time amplifies the detection signal obtained from the detection coil of the sensor 1t, and converts it into a voltage signal proportional to the magnetic anisotropy. This is a magnetostriction measurement unit that outputs. 14 is a motor driver which supplies a travel drive signal to the traveling trolley I2 to cause it to travel;
An encoder signal is fed back as position information of the driving result. 15 h A/D converter, 16 is for example R3232C
17 is a personal computer 7
(hereinafter referred to as a personal computer), 18 is a data display section using a CRT or liquid crystal.
第４図の動作を説明する。管材の円周方向の応力を；ｊ
ＰＪ定するには、例えば管材の中心軸に対する垂直面上
の管材外周面に、図示されないレール又は／及びギヤを
取付け、このレール又は／及びギヤ上にホルダを介して
走行装置部１ｏを走行可能に取付ける。次にパソコン１
７はインタフェース１Ｇを介してモータ・ドライバ１４
に１回転の走行指令を与え、モータ・ドライバ１４は前
記レール又は／及びギヤ上の走行装置ｌＯを管周に沿っ
て１回転走行させる０この走行中に、磁気異方性センサ
ＩＩ（磁歪センサ２と同一のもの）が第１図（ｂ）に示
される管材外周面上の０°〜３６０９間の各角度位置に
おいて、該センサｌｌからそれぞれ検出された各検出信
号は磁歪ｄｐｊ定部１３により信号増幅後出力され、さ
らに該出力はＡ／Ｄ変換器１５により量子化され、パソ
コン１７に供給される。パソコン１７は磁気異方性セン
サ１１の管材外周上の方位を示す各角度に対するセンサ
出力値をデータ表示部１８に表示させ、必要の場合図示
されないプリンタによりハードコピーを出力する。本測
定装置のデータ表示部１８に表示されたデータ又はプリ
ンタにより出力されたハードコピーデータに基づき、本
発明に係る管の偏平応力推定処理を行うことができる。The operation shown in FIG. 4 will be explained. The stress in the circumferential direction of the pipe material;
To determine the PJ, for example, a rail or/and a gear (not shown) is attached to the outer circumferential surface of the pipe on a plane perpendicular to the central axis of the pipe, and the traveling device section 1o can run on this rail or/and gear via a holder. Attach to. Next, computer 1
7 is the motor driver 14 via the interface 1G.
The motor driver 14 causes the traveling device lO on the rail or/and gear to travel one rotation along the circumference of the pipe.During this traveling, the magnetic anisotropy sensor II (magnetostrictive sensor At each angular position between 0° and 3609 on the outer circumferential surface of the tube shown in FIG. After the signal is amplified, it is output, and the output is further quantized by the A/D converter 15 and supplied to the personal computer 17. The personal computer 17 causes the data display section 18 to display the sensor output value for each angle indicating the direction on the outer circumference of the tube material of the magnetic anisotropy sensor 11, and outputs a hard copy using a printer (not shown) if necessary. Based on the data displayed on the data display section 18 of the measuring device or the hard copy data output by the printer, the flat stress estimation process of the tube according to the present invention can be performed.
第５図（ａ）〜（ｃ）は本発明に係る管の偏平応力をＳ
ＩＮ２θ曲線により近似する方法を説明する図である。FIGS. 5(a) to 5(c) show the flattening stress S of the tube according to the present invention.
FIG. 3 is a diagram illustrating a method of approximation using an IN2θ curve.
第５図（ａ）は管の偏平応力状態における磁歪センサ出
力を示す図であり、磁歪センサの管周上の方位を示す角
度に対する各磁歪センサ出力（単位はボルトである）を
それぞれ十印で示している。FIG. 5(a) is a diagram showing the output of the magnetostrictive sensor in the state of flattening stress of the tube, and the output of each magnetostrictive sensor (unit: volt) is indicated by a 10 mark for each angle indicating the direction of the magnetostrictive sensor on the circumference of the tube. It shows.
第５図（ｂ）は同図（ａ）の磁歪センサ出力よりＳＩＮ
θ近似値を減算して得られた偏差値を示す図であり、同
図（ａ）と同一角度に対する各偏差値（単位はボルト）
をそれぞれ十印で示している。Figure 5(b) shows the SIN from the magnetostrictive sensor output in Figure 5(a).
It is a diagram showing the deviation values obtained by subtracting the θ approximate value, and each deviation value (unit is volt) for the same angle as in the figure (a).
are each indicated by a ten mark.
第５図（ｃ）は第５図（ｂ）で示された偏差値とこれに
近似する５ＩＮ２θ近似曲線を示す図でありり、同図（
ｂ）と同一角度に対して、十印が各偏差値（単位はボル
ト）を、実線が５ＩＮ２θ近似曲線を示している。第５
図（ｃ）により管の偏平状態の応力計測値よりＳＩＮθ
近似値を減算して得られた偏差値は、磁歪センサが管周
方向に沿って１回転するときに、磁歪センサの１７２回
転毎に周期的に変化するＳＩＮ２θ曲線によりほぼ近似
し得ることが判る。FIG. 5(c) is a diagram showing the deviation value shown in FIG. 5(b) and a 5IN2θ approximate curve that approximates it.
For the same angle as in b), the cross marks indicate each deviation value (in volts), and the solid line indicates the 5IN2θ approximate curve. Fifth
From the stress measurement value in the flat state of the pipe, SINθ is shown in Figure (c).
It can be seen that the deviation value obtained by subtracting the approximate value can be approximately approximated by the SIN2θ curve that changes periodically every 172 rotations of the magnetostrictive sensor when the magnetostrictive sensor rotates once along the pipe circumferential direction. .
第６図（ａ）及び（ｂ）は−膜内な偏平応力と本発明に
係る５ＩＮ２θ近似曲線を説明する図である。FIGS. 6(a) and 6(b) are diagrams for explaining the flat stress within the film and the 5IN2θ approximate curve according to the present invention.
同図（ａ）は偏平応力の最大値の方位が第３図（ａ）と
角度φだけ異る一般的な場合の偏平応力状態を示してい
る。また同図（ｂ）は同図（ａ）の偏平応力状態におけ
る前記５ＩＮ２θ近似曲線である、Ａ−ｓｉｎ２（θ＋
φ）を示している。ここでＡは最大信号振幅値、φは偏
平の軸と磁歪センサの基準軸（角度０’）との角度差で
ある。FIG. 3(a) shows a general flattened stress state in which the direction of the maximum value of flattened stress differs from that in FIG. 3(a) by an angle φ. In addition, the figure (b) is the 5IN2θ approximation curve in the flat stress state of the figure (a), A-sin2(θ+
φ) is shown. Here, A is the maximum signal amplitude value, and φ is the angular difference between the flat axis and the reference axis (angle 0') of the magnetostrictive sensor.
第７図は配管の曲管近傍の直管部における各測定位置の
例を示す図であり、いま曲管近傍の溶接位置より３４５
ｍｍ離れた位置に橋台等に架管する固定位置があり、こ
の溶接位置から固定位置に至る間のそれぞれ図示された
４つの位置に、測定位置■、■、■及び■を設けたこと
を示している。Figure 7 is a diagram showing an example of each measurement position in a straight pipe section near a curved pipe.
This indicates that there is a fixed position where the pipe is installed on an abutment, etc., at a position mm apart, and measurement positions ■, ■, ■, and ■ are provided at the four positions shown in the diagram between this welding position and the fixed position. ing.
第８図（ａ）〜（ｄ）は第７図に示された各測定位置■
〜■における磁歪センサ出力をそれぞれ示す図である。Figures 8(a) to (d) show each measurement position shown in Figure 7.
It is a figure which shows the magnetostrictive sensor output in - (■), respectively.
同図の（ａ）は測定位置の、（ｂ）は測定位置■、（ｃ
）は測定位置■、（ｄ）はｉ’１ｌｌＪ定位置■のそれ
ぞれの位置における磁歪センサの各測定値（単位はボル
ト）を、横軸の管周上の方位を示す角度に対応してそれ
ぞれ十印で示している。In the same figure, (a) is the measurement position, (b) is the measurement position ■, (c
) is the measurement position ■, (d) is the i'1llJ fixed position ■, and the measured values (units are volts) of the magnetostrictive sensor are shown in correspondence to the angle indicating the direction on the tube circumference of the horizontal axis. It is indicated by ten marks.
第９図（ａ） 〜（ｄ）は第８図（ａ） 〜（ｄ）の各
磁歪センサ出力よりそれぞれＳＩＮθ近似値を減算して
得られた偏差値をＳ ＩＮ２θ曲線により近似した結果
を示す図である。同図の（ａ）〜（ｄ）はそれぞれ測定
位置■〜■において、第８図の横軸と同一の角度に対す
る上記各偏差値を十印で示し、実線はこの偏差値を近似
する５ＩＮ２θ近似曲線をそれぞれ示している。Figures 9(a) to (d) show the results of approximating the deviation values obtained by subtracting the SINθ approximate value from each magnetostrictive sensor output in Figures 8(a) to (d) using the SIN2θ curve. It is a diagram. (a) to (d) of the same figure indicate the above deviation values with respect to the same angle as the horizontal axis of Fig. 8 at measurement positions ■ to ■, respectively, with 10 marks, and the solid line is a 5IN2θ approximation that approximates this deviation value. Each curve is shown.
第１０図（ａ） 〜（ｄ）は第８図（ａ） 〜（ｄ）の
各磁歪センサ出力よりそれぞれ５ＩＮ２θ近似値を減算
して得られた偏差値をＳＩＮθ曲線により近似した結果
を示す図である。同図の（ａ）〜（ｄ）はそれぞれ測定
位置■〜■において、第８図の横軸と同一の角度に対す
る上記各偏差値をそれぞれ十印で示し、実線はこの偏差
値に近似するＳＩＮθ近似曲線をそれぞれ示している。Figures 10(a) to (d) are diagrams showing the results of approximating the deviation values obtained by subtracting the 5IN2θ approximate value from each magnetostrictive sensor output in Figures 8(a) to (d) using a SINθ curve. It is. (a) to (d) of the same figure indicate the above-mentioned deviation values for the same angle as the horizontal axis of Fig. 8 at the measurement positions ■ to ■, respectively, with 10 marks, and the solid line indicates the SIN θ that approximates this deviation value. Each approximate curve is shown.
第９図（ａ） 〜（ｄ）及び第１Ｏ図（ａ） 〜（ｄ）
により判るように、曲管近傍の直管部における測定位置
■及び■においては、偏平化の影響による５ＩＮ２θ成
分が存在するため、第９図（ａ）及び（ｂ）に示される
ように前記偏差値（計測値とＳＩＮθ近似値との偏差値
）を５ＩＮ２θ近似曲線により十分近似し得ることが明
らかである。Figures 9(a) to (d) and Figures 10(a) to (d)
As can be seen from Figure 9(a) and (b), there is a 5IN2θ component due to the influence of flattening at measurement positions ■ and ■ in the straight pipe near the curved pipe. It is clear that the value (deviation value between the measured value and the SINθ approximate value) can be sufficiently approximated by the 5IN2θ approximate curve.
本発明においては、あらかじめ曲管近傍の直管部におけ
る偏平化応力を歪ゲージ等により実測し、この実測値と
前記５ＩＮ２θ近似値とを対応させた較正曲線（図示せ
ず）を作成しておく。従って曲管近傍の磁歪センサ出力
より前記５ＩＮ２θ近似値を算出し、この算出値と前記
較正曲線とから対応する管偏平化に伴う応力を推定する
ことができる。In the present invention, the flattening stress in the straight pipe section near the curved pipe is actually measured using a strain gauge, etc., and a calibration curve (not shown) is created by correlating the measured value with the 5IN2θ approximate value. . Therefore, the 5IN2θ approximate value can be calculated from the output of the magnetostrictive sensor near the curved pipe, and the stress associated with the corresponding flattening of the pipe can be estimated from this calculated value and the calibration curve.
また曲管から離れるに従い偏平化の影響は小さくなり、
直管部のａＦＪ定位置■及び■においては、第１Ｏ図（
Ｃ）及び（ｄ）に示されるように前記偏差値（計測値と
５ＩＮ２θ近似値との偏差値）をＳＩＮθ近似曲線で近
似し得ることが判る。これは曲げ応力成分はＳＩＮθ成
分を有することによるものである。In addition, the effect of flattening becomes smaller as you move away from the curved pipe.
At aFJ fixed positions ■ and ■ of the straight pipe section, see Figure 1O (
As shown in C) and (d), it can be seen that the deviation value (deviation value between the measured value and the 5IN2θ approximate value) can be approximated by the SINθ approximate curve. This is because the bending stress component has a SINθ component.
前記偏平応力の推定の場合と同様に、曲管よりやや離れ
た直管部における応力を歪ゲージ等により実測し、この
実測値と前記ＳＩＮθ近似値とを対応させた較正曲線（
図示せず）をあらかじめ作成しておけば、前記直管部に
おける磁歪センサ出力より前記ＳＩＮθ近似値を算出し
、この算出値と前記較正曲線から対応する曲げ応力を推
定することができる。As in the case of estimating the flattened stress, the stress in the straight pipe section slightly distant from the curved pipe is actually measured using a strain gauge, etc., and a calibration curve (
(not shown) is created in advance, the SINθ approximate value can be calculated from the output of the magnetostrictive sensor in the straight pipe section, and the corresponding bending stress can be estimated from this calculated value and the calibration curve.
また上記実施例においては、磁歪センサを管材の外周面
上を非接触で走行させる例を示したが、同様に磁歪セン
サを管材の内周面上を非接触で走行させるようにしても
よい。またこの場合に磁歪センサを走行させずに、管材
をその中心軸に対して回転させ、磁歪センサを固定する
ようにしてもよい。いずれの場合も磁歪センサと管材と
が相対移動をすればよく、一方を固定し他方を移動させ
ることにより同一効果を得ることができる。Further, in the above embodiment, an example was shown in which the magnetostrictive sensor runs on the outer circumferential surface of the tube without contact, but the magnetostrictive sensor may similarly run on the inner circumference of the tube in a non-contact manner. Further, in this case, the magnetostrictive sensor may be fixed by rotating the tube material about its central axis without causing the magnetostrictive sensor to travel. In either case, the magnetostrictive sensor and the tube only need to move relative to each other, and the same effect can be obtained by fixing one and moving the other.
［発明の効果］
以上のように本発明によれば、磁歪センサが管材の外周
面上または内周面上を非接触状態でト目苅移動するｉＰ
ｊ定装置を用いて、前記管材の管周方向の応力分布をＳ
ＩＮ曲線で近似して推定する方法において、管材曲管部
近傍の直管部において計？＋Ｉ１１された磁歪センサ出
力ＳＩＮθ近似値を減算して得られた偏差値をＳ ＩＮ
２θｔＩＩＩ線により近似し、該近似した５ＩＮ２θ曲
線のｆ３号振幅値より対応する前記直管部に生じる偏差
化に伴う応力値を推定することができるようにしたので
、従来磁歪センサを用いたＳＩＮ近似法では計測できな
かった偏平応ツノを計Ａ１１１可能とし、磁歪センサの
計１１１１１ｊ範囲拡大の効果が得られる。[Effects of the Invention] As described above, according to the present invention, the magnetostrictive sensor moves on the outer peripheral surface or the inner peripheral surface of the pipe material in a non-contact state.
The stress distribution in the circumferential direction of the tube material is determined by using a
In the method of estimation by approximation using an IN curve, the total ? The deviation value obtained by subtracting the +I11 magnetostrictive sensor output SINθ approximate value is S IN
The 2θtIII line is approximated, and the stress value due to deviation occurring in the corresponding straight pipe portion can be estimated from the f3 amplitude value of the approximated 5IN2θ curve, so SIN approximation using the conventional magnetostrictive sensor The oblate horn, which could not be measured by the method, can be measured by a total of A111, and the effect of expanding the range of the magnetostrictive sensor by a total of 11111j can be obtained.
第１図（ａ＞及び（ｂ）は先願に係る磁歪応力ＡｐＪ定
法を説明する図、第２図（ａ）及び（ｂ）は第１図の磁
歪応力Ａｌ１１定広によるＳＩＮ近似注を説明する図、
第３図（ａ）は管が偏平したときの応力状態を示す図、
第３図（ｂ）は同図（ａ）の状態における磁歪センサ出
力を示す図、第４図は本発明の管の偏平応力推定方法を
適用する管の応力測定装置のブロック図、第５図（ａ）
〜（ｃ）は本発明に係る管の偏平応力をＳＩＮ２θ曲線
により近似する方法を説明する図、第６図（ａ）及び（
ｂ）は−膜内な偏平応力と本発明に係る５ＩＮ２θ近似
曲線を説明する図、第７図は配管の曲管近傍の直管部に
おける各測定位置の例を示す図、第８図（ａ）〜（ｄ）
は第７図に示された各ＪＩＩＪ定位置における磁歪セン
サ出力をそれぞれ示す図、第９図（ａ）〜（ｄ）は第８
図（ａ）〜（ｄ）の各磁歪センサ出力よりそれぞれＳＩ
Ｎθ近似値を減算し、その結果を５ＩＮ２θ曲線により
近似した結果を示す図、第１０図（ａ）〜（ｄ）は第８
図（ａ）〜（ｄ）の各磁歪センサ出力よりそれぞれ５Ｉ
Ｎ２θ近似値を減算し、その結果をＳＩＮθ曲線により
近似した結果を示す図である。
図において、１は円柱材料、２は磁歪センサ、１０は走
行装置部、１１は磁気異方性センサ、１２は走行台車、
１３は磁歪？ｔＦＪ定部、１４はモータ・ドライバ、１
５はＡ／Ｄ変換器、１Ｂはインタフェース、１７はパソ
コン、１８はデータ表示部である。Figures 1 (a) and (b) are diagrams explaining the magnetostrictive stress ApJ standard method according to the prior application, and Figures 2 (a) and (b) are diagrams explaining the SIN approximation note using the magnetostrictive stress Al11 constant widening in Figure 1. figure,
Figure 3(a) is a diagram showing the stress state when the tube is flattened;
FIG. 3(b) is a diagram showing the magnetostrictive sensor output in the state of FIG. 3(a), FIG. 4 is a block diagram of a tube stress measuring device to which the tube flat stress estimation method of the present invention is applied, and FIG. (a)
~(c) are diagrams illustrating a method of approximating the flat stress of a pipe according to the present invention by a SIN2θ curve, and Figures 6(a) and (
b) is a diagram explaining the flat stress in the membrane and the 5IN2θ approximate curve according to the present invention; FIG. 7 is a diagram showing an example of each measurement position in a straight pipe section near a curved pipe; )~(d)
9 shows the output of the magnetostrictive sensor at each JIIJ fixed position shown in FIG. 7, and FIGS.
SI from each magnetostrictive sensor output in figures (a) to (d)
Figures 10 (a) to (d) show the results of subtracting the Nθ approximation value and approximating the result by a 5IN2θ curve.
5I from each magnetostrictive sensor output in figures (a) to (d)
FIG. 7 is a diagram showing the result of subtracting the N2θ approximation value and approximating the result by a SINθ curve. In the figure, 1 is a cylindrical material, 2 is a magnetostrictive sensor, 10 is a traveling device section, 11 is a magnetic anisotropy sensor, 12 is a traveling trolley,
Is 13 magnetostrictive? tFJ constant part, 14 is motor driver, 1
5 is an A/D converter, 1B is an interface, 17 is a personal computer, and 18 is a data display section.
Claims (1)
状態で相対移動する測定装置を用いて、前記管材の管周
方向の応力分布をＳＩＮ曲線で近似して推定する方法に
おいて、 管材曲管部近傍の直管部において計測された磁歪センサ
出力よりＳＩＮθ近似値を減算して得られた偏差値をＳ
ＩＮ２θ曲線により近似し、該近似したＳＩＮ２θ曲線
の信号振幅値より対応する前記直管部に生じる偏平化に
伴う応力値を推定することを特徴とする管の偏平応力推
定方法。[Claims] Using a measuring device in which a magnetostrictive sensor moves relatively on the outer circumferential surface or inner circumferential surface of the tube material in a non-contact state, the stress distribution in the circumferential direction of the tube material is estimated by approximating it with a SIN curve. In the method of
A method for estimating flattening stress in a pipe, comprising: approximating an IN2θ curve, and estimating a stress value due to flattening occurring in the corresponding straight pipe portion from a signal amplitude value of the approximated SIN2θ curve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31417389A JPH0769226B2 (en) | 1989-12-05 | 1989-12-05 | Tube flat stress estimation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31417389A JPH0769226B2 (en) | 1989-12-05 | 1989-12-05 | Tube flat stress estimation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03176627A true JPH03176627A (en) | 1991-07-31 |
| JPH0769226B2 JPH0769226B2 (en) | 1995-07-26 |
Family
ID=18050130
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31417389A Expired - Lifetime JPH0769226B2 (en) | 1989-12-05 | 1989-12-05 | Tube flat stress estimation method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0769226B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07110270A (en) * | 1993-10-13 | 1995-04-25 | Osaka Gas Co Ltd | Method for measuring magnetostrictive stress of pipe |
| JP2010025604A (en) * | 2008-07-16 | 2010-02-04 | Tokyo Gas Co Ltd | Bent pipe stress evaluation method and bent pipe stress evaluation device |
| JP2010025606A (en) * | 2008-07-16 | 2010-02-04 | Tokyo Gas Co Ltd | Bent pipe stress evaluation method and bent pipe stress evaluation device |
-
1989
- 1989-12-05 JP JP31417389A patent/JPH0769226B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07110270A (en) * | 1993-10-13 | 1995-04-25 | Osaka Gas Co Ltd | Method for measuring magnetostrictive stress of pipe |
| JP2010025604A (en) * | 2008-07-16 | 2010-02-04 | Tokyo Gas Co Ltd | Bent pipe stress evaluation method and bent pipe stress evaluation device |
| JP2010025606A (en) * | 2008-07-16 | 2010-02-04 | Tokyo Gas Co Ltd | Bent pipe stress evaluation method and bent pipe stress evaluation device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0769226B2 (en) | 1995-07-26 |
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