JP6491054B2 - Apparatus and method for evaluating deformation amount of structural material - Google Patents

Description

  The present invention relates to a deformation evaluation apparatus and method for a structural material used in a place where it is difficult to install a high-precision measuring instrument such as a severe environment such as high temperature and high radiation dose, and in particular, the deformation amount of the structural material. The present invention relates to an apparatus and a method for evaluating a deformation amount of a structural material that can be evaluated by a simple method.

  Equipment that is used in a high-temperature environment during operation, such as a power plant or chemical plant, is subject to creep or damage to the metal members that make up the equipment by applying repeated loads during steady-state operation or unsteady operation such as start / stop or load fluctuations. It is assumed that characteristic damage occurs at high temperatures such as creep fatigue. When such damage accumulates, a microscopic crack grows inside the structure of the metal member, lowering the strength of the member, and finally causing destructive phenomena such as deformation and breakage of the member. Therefore, usually, a master curve corresponding to the load condition of the device is created, and the structural design of the device is made based on the predicted life from the master curve. In order to manage this life, it is necessary to detect changes such as strain in the structural material as the first step.

  In detecting changes such as strain, the following should be considered. The damage state of high-temperature equipment that operates over a long period of time depends on the accumulation of damage due to operating conditions and load conditions that change sequentially. For this reason, it is not easy to accurately predict the degree of damage in advance. Therefore, there is a demand for a technique for accurately grasping the damaged state by sequentially evaluating the members of the equipment in operation.

  In addition, it is desirable to use a non-destructive measurement method to evaluate the damage state without hindering the operation of the device. For example, it is conceivable to evaluate the damage state by transmitting ultrasonic waves from a probe brought into contact with the member surface and measuring the modulation of the ultrasonic waves that have passed through the inside of the member. In addition, by continuously measuring the amount of deformation and displacement on the surface of the member with a strain gauge or displacement meter, it is possible to detect abnormal deformation of the member as the damage progresses, in addition to estimating the stress distribution generated in the member. It is thought that it can also be done.

  However, as described at the beginning, it is not easy for personnel to enter for measurement in a harsh environment where the use environment of equipment is at a high temperature or exposed to high radiation such as a nuclear power plant. Moreover, the place and conditions where this can be installed are limited from the point of durability of the measuring device.

  In view of such a situation, a measurement technique capable of measuring deformation and displacement of an evaluation target device relatively easily even under a severe environment such as a high temperature and a high dose is desired.

  As a technique for detecting a change in a structural material, it is known to detect by irradiating a structural material, which is an object to be measured, with light and measuring the reflected scattered light. For example, Patent Document 1 provides a method for easily measuring strain (deformation) of wood, metal material, resin material, etc. by effectively using retroreflective beads. In this case, retroreflective beads are uniformly attached to the measurement surface of the object to be measured, light is applied to the attachment surface, and the amount of reflection is compared before and after the occurrence of the distortion. Measure. ”

  According to Patent Document 2, “a reflector provided with a plurality of black bars formed at predetermined intervals is attached to the surface of an object to be measured, and a light projecting optical fiber is formed on the reflector. In this method, the light reflected by the reflector is received by the optical fiber for receiving light, and the received light amount or the distortion amount corresponding to the received light amount is displayed on the display device. is there.

JP 2008-139273 A JP-A-8-101022

  In Patent Document 1, a retroreflective bead has a function of reflecting incident light in the same direction. Here, when the measured object to which the bead is attached is deformed, the bead area occupied per unit area changes. Thus, the change in the amount of reflected light is utilized. Further, Patent Document 2 utilizes the fact that the amount of reflected light changes depending on the proportion of black lines included in the measurement area when the object to be measured with the reflector attached thereto is deformed.

  In both Patent Documents 1 and 2, the amount of light accompanying the change in the proportion of the reflector (beads in Patent Document 1) or non-reflectors (black lines in Patent Document 2) in the region irradiated with light. Changes are the subject of evaluation. However, with these methods, changes in the evaluation target area are offset by fluctuations in the brightness of the entire surrounding environment, and it is difficult to measure accurately.

  In view of the above, it is an object of the present invention to provide a structural material deformation amount evaluation apparatus and method that are effective in appropriately measuring and evaluating the deformation and displacement of equipment and structural materials that operate in harsh environments. .

  In order to solve the above problems, for example, the configuration described in the claims is adopted. The present invention includes a plurality of means for solving the above problems. To give an example, a structure for detecting deformation in a structural material using a structural material having an uneven region formed on the surface as a measurement object. An apparatus for evaluating a deformation amount of a material, a light irradiation unit for irradiating light on an uneven region on a surface of a structural material, a light observation unit for measuring the wavelength of light reflected and scattered in the uneven region, and a plurality of front and back It is characterized by comprising a determination unit for detecting deformation in the structural material using the wavelength difference of the reflected and scattered light obtained from the light observation result.

  In addition, a structural material with an uneven area formed on the surface is a measurement object, and a structural material deformation amount evaluation method for detecting deformation in the structural material. The uneven surface area of the structural material is irradiated with light, The wavelength of the light reflected and scattered by the uneven region is measured, and the deformation in the structural material is detected using the wavelength difference of the reflected and scattered light obtained from a plurality of light observation results.

  According to the present invention, the deformation and displacement of the measurement object can be evaluated by observing the reflection and scattered light generated by the deformation of the uneven area in conjunction with the measurement object. In particular, if the amount of deformation of the object to be measured, and the correlation between the amount of displacement and the optical characteristics are known in advance, the amount of deformation can be accurately evaluated without using a highly accurate measuring device.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the deformation amount evaluation apparatus of the structural material which concerns on Example 1 of this invention, and is a figure which shows the initial state at the time of structural material installation. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the deformation evaluation apparatus of the structural material which concerns on Example 1 of this invention, and is a figure which shows the state at the time of observation. The schematic diagram which shows the correlation with the angle of the light observation part in the deformation amount evaluation method of this invention, and the main wavelengths of the observed light. It is a schematic diagram which shows the deformation amount evaluation apparatus of the structural material which concerns on Example 2 of this invention, and is a figure which shows the initial state at the time of structural material installation. It is a schematic diagram which shows the deformation evaluation apparatus of the structural material which concerns on Example 2 of this invention, and is a figure which shows the state at the time of observation. The schematic diagram which shows the correlation with the angle of the light observation part in the deformation amount evaluation method of this invention, and the main wavelengths of the observed light.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a structural material deformation amount evaluation method and a deformation amount evaluation apparatus according to the present invention will be described with reference to the drawings.

  A structural material deformation amount evaluation method and a deformation amount evaluation apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS.

  FIG. 1 shows a structural material deformation amount evaluation apparatus 20 according to an embodiment of the present invention. The deformation amount evaluation apparatus 20 is provided on the surface of the device under test 10 and monitors the uneven region 1 that can be deformed following the deformation of the device under test 10. The deformation amount evaluation apparatus 20 includes a light irradiating unit 2 for irradiating light from the normal direction of the surface of the concavo-convex region 1 and a concavo-convex region for observing light scattered and reflected on the concavo-convex surface region 1. The light observation unit 3 is installed at a position that forms an angle θ with respect to the normal line 1, the determination unit 4 obtains the amount of change in wavelength using the wavelength detected by the light observation unit, and the like.

  Here, the uneven shape provided on the surface of the uneven region 1 causes diffraction and interference of the irradiated light if the light irradiated from the light irradiation unit 2 is visible light (wavelength 380 to 780 nanometers). Therefore, an uneven shape having a size equal to or smaller than the wavelength of light is provided, and this uneven shape can be appropriately set according to the evaluation method. For example, a columnar shape, a hole shape, a lamellar shape (a bowl shape), and the like can be mentioned. In the present invention, since the diffraction and interference of light irradiated to the uneven region 1 is used, the uneven shape is not randomly arranged, but according to a desired function. It is desirable to have a regular arrangement.

  As the light irradiation unit 2, for example, a lamp that irradiates white light including a continuous wavelength distribution in the visible range can be used. Moreover, as the light observation part 3, the camera which can discriminate | determine the color of the light reflected and scattered on the uneven | corrugated area | region 1 surface with a color image, for example can be used.

  Next, a method for evaluating the deformation amount of the structural material will be described. In FIG. 1, the white light emitted from the light irradiator 2 to the uneven region 1 is scattered by diffraction and interference due to the effect of the uneven shape applied to the surface of the uneven region 1, and the normal line and angle of the uneven region 1. The light is observed as scattered light having the wavelength λ1 by the light observation unit 3 provided at the position forming θ, and the wavelength λ1 is stored in the determination unit 4 as the first wavelength. Here, the state of FIG. 1 is assumed to be an initial state when a structural material as the DUT 10 is installed. In the initial state, it is assumed that the length in the height direction of the DUT 10 is H1, and the length in the height direction of the uneven region 1 installed in the height direction of the DUT 10 is X1.

  On the other hand, FIG. 2 shows an observation state after a lapse of time from the initial state. During this time, the length 10 of the object to be measured is displaced to H2 for some reason, and accordingly, the length in the height direction of the uneven area 1 installed in the height direction of the object 10 to be measured is also displaced to X2. It shall be. In this case, it is assumed that there is no change in the arrangement relationship between the light irradiation unit 2 and the light observation unit 3. In this case, in response to the fact that the uneven shape of the uneven region 1 is changed due to the influence of the displacement in the height direction, the light observation unit 3 observes the scattered light having the wavelength λ2, and the determination unit 4 displays The wavelength λ2 is stored as the wavelength and is used for the subsequent comparison processing. The concavo-convex shape of the concavo-convex region 1 in this case assumes that, for example, the concavo-convex of 1 nanometer pitch is transformed into the concavo-convex of 1.2 nanometer pitch.

  FIG. 3 shows the angle θ formed by the normal line of the uneven region 1 verified by the present inventors and the correlation expressed by replacing the color of the light observed by the light observation unit 3 at that time with the wavelength λ. Yes. The horizontal axis is the angle θ, and the vertical axis is the wavelength λ. The larger the angle θ, the longer the wavelength of the scattered light and the closer to red. In addition, this characteristic shows a tendency of saturation, and also shows a characteristic of saturation tendency that varies depending on the shape of the uneven region 1. Here, shape A and shape B are the results of samples having similar shapes and different dimensions, but from this result, even when the angle θ is the same, the main wavelength λ of light observed when the uneven shape changes Indicates that the color of light changes.

  That is, when the main wavelength of the scattered light for the shape A observed by the light observation unit 3 in FIG. 1 is λ1, the vertical dimension of the DUT 10 is from H1 to H2 as shown in FIG. As the dimension of the concavo-convex region 1 extends from X1 to X2 as it extends, the concavo-convex shape changes, and then the main wavelength of the scattered light of the shape B observed by the light observation unit 3 changes to λ2. The present invention captures that a change in wavelength Δλ12 occurs during this time. The determination unit 4 compares the wavelength λ1 in the initial state of FIG. 1 with the wavelength λ2 at the time of observation in FIG. 2, detects a change in position or the like according to the value of the difference, and further determines the direction and magnitude of the displacement. Is obtained by calculation.

  As described above, the deformation of the uneven region 1 can be evaluated by the change of the wavelength λ of the scattered light by the configuration of the present invention. In particular, as shown in FIG. 3, the correlation between the difference in pattern shape and the wavelength λ of scattered light is investigated in advance, and compared with the wavelength of light actually observed by the light observation unit 3, the DUT 10 It is also possible to quantitatively evaluate the amount of deformation occurring in the measurement object, and the amount of deformation of the DUT 10 can be determined by the difference in the color of the scattered light.

  Therefore, the determination unit 4 stores the characteristics of FIG. 3, detects the occurrence of deformation from the wavelength difference, and determines the magnitude of deformation in the structural material from the predetermined relationship between the wavelength difference and the deformation amount. It is possible to estimate and output the length.

  This is because, by applying the present invention to actual plant equipment, in addition to the uneven area provided on the surface of the object to be measured, the deformation amount of the object to be measured by a relatively simple device such as the lamp 2 and the monitoring camera 3, for example. It means that can be evaluated.

  A structural material deformation amount evaluation method according to Embodiment 2 of the present invention will be described with reference to FIGS.

  The deformation amount evaluation apparatus shown in FIGS. 4 and 5 basically has the same configuration as the deformation amount evaluation apparatus described in the first embodiment. In FIGS. 1 and 2, the detection of the height direction displacement H is described, but in FIGS. 4 and 5, it is detected that the lateral width W has changed. A method for evaluating the deformation amount of the structural material using the deformation amount evaluation apparatus of the present invention even when the position of the uneven region 1 provided on the surface of the object to be measured changes will be described.

  In FIG. 4, the deformation amount evaluation apparatus according to the second embodiment is similar to the deformation amount evaluation apparatus according to the first embodiment described above. A light observation unit 3 for observing light scattered and reflected from the uneven surface area 1, a determination unit 4 for obtaining a change in wavelength using the wavelength detected by the light observation unit 3, and the like. In the second embodiment, unlike the first embodiment, the device under test 10 originally has the width W1 as shown in FIG. 4, but extends in the horizontal direction as shown in FIG. This shows that the position is displaced in the normal direction approaching the light irradiation unit 3 by Δ from the position.

  Thus, before and after the uneven region 1 is displaced by Δ in the normal direction, when the uneven region 1 is within the field of view of the light observation unit 3, the normal direction of the uneven region 1 is Whereas the angle in the installation direction of the light observation unit 3 is θa, the angle in the installation direction of the light observation unit 3 after the uneven region 1 is displaced changes to θb as shown in FIG. Here, FIG. 6 is a diagram showing the same correlation between the angle θ and the wavelength as in FIG. 3, but the above phenomenon in FIG. 6 is the same pattern shape (for example, shape A). It is shown that the wavelength λ changes from λa to λb and changes in Δλab.

  That is, when the main wavelength of the scattered light observed by the light observation unit 3 in FIG. 4 is λa, the position of the uneven region 1 changes as shown in FIG. As θ changes from θa to θb, the main wavelength of the scattered light observed by the light observation unit 3 changes to λb, and a change in the wavelength Δλab occurs between them. Therefore, it can be said that the displacement amount of the DUT 10 can be evaluated in the same manner as in the first embodiment.

  So far, it has been described that the deformation amount and displacement amount of the object to be measured can be evaluated by the uneven area 1 provided on the surface of the object to be measured, the light irradiation unit 2, the light observation unit 3, and the determination unit 4. However, in an actual plant, both deformation and displacement of the uneven region 1 may overlap. In such a case, for example, the evaluation device 20 of the present invention may be arranged at a plurality of positions of the object to be measured, and the respective measurement results may be combined to correct each other, or obtained by other than the evaluation device 20 of the present invention. Correction may be performed using the obtained information.

  In the second embodiment, the displacement of the uneven area 1 due to the deformation of the object to be measured has been described. However, the uneven area may be displaced due to a deviation in the installation position of the object to be measured. In this case, the deformation amount of the device under test is not evaluated, but can be used for evaluating the position where the device under test 10 is installed. For example, it is possible to evaluate and determine whether plant equipment structures, various pipes and supporting members are installed at their original correct positions, and the deformation amount evaluation apparatus and evaluation method of the present invention can be applied to the entire plant. It can be said that this is an effective technique for maintaining the soundness of the company.

  In Example 1 and Example 2, the characteristics of FIGS. 3 and 6 have been described. If this characteristic is used, it is possible to obtain one step forward and convert it into information on the amount of deformation rather than simply detecting deformation.

  For example, in FIG. 3, it is assumed that only the wavelength changes by Δλ12 while the angle θ remains the same. Further, assuming that the initial shape is A and possesses characteristics of a plurality of shapes, it is possible to specify the characteristics of the shape B with reference to the variation Δλ12. In this case, since the shapes A and B are information having the concept of length, the deformation amount can be estimated as a difference in length.

  In FIG. 6, it is assumed that the angle θ changes and the wavelength changes by Δλab. The premise is that a change in angle is detected. If the change in angle and the change in wavelength match on the characteristics of the shape A, the deformation amount can be estimated from the angle information. When the change in the angle and the change in the wavelength do not coincide with each other in the characteristics of the shape A, it is possible to estimate the displacement of the complex shape by judgment including information on other shapes.

  As mentioned above, although embodiment regarding the deformation evaluation apparatus and method of this invention was described, this invention is not limited to these structures.

  For example, even if the light irradiation unit 2 is installed at a position that forms an angle with respect to the normal direction of the concavo-convex region 1 in FIGS. 1 and 2, evaluation is possible if scattered light reaches the light observation unit 3. is there. Further, even if the light irradiation unit 2 and the light observation unit 3 are switched to the opposite positions, they are optically equivalent and there is no problem, and scattered light generated by irradiating the uneven region 1 from the light irradiation unit 2 is the light observation unit. As long as it reaches 3, the relative positions of the uneven region 1, the light irradiation unit 2, and the light observation unit 3 may be changed according to the state of the installation location.

  Moreover, although the above-mentioned Example assumes fixing each position of the uneven | corrugated area | region 1, the light irradiation part 2, and the light observation part 3, For example, angle (theta) which the light observation part 3 makes with the normal line of the uneven | corrugated area | region 1 Can be continuously changed, and more data can be obtained by measuring the distribution of the angle θ and the observed wavelength λ. Further, if the light observation unit 3 is installed not only in the vertical direction in which deformation occurs in FIG. 1 but also in the direction perpendicular to the paper surface (not shown), the amount of deformation in each direction can be evaluated simultaneously. Alternatively, if one light observation unit 3 can be rotated around the uneven region 1, data from each direction can be obtained continuously.

  Next, although it is the method of providing the uneven | corrugated area | region 1 in the to-be-measured object 10 surface, you may provide an uneven | corrugated shape directly to the to-be-measured object surface. However, the present invention requires a fine uneven shape of approximately 1 micrometer or less in order to use light diffraction and interference, and it is difficult to form this by machining. Therefore, for example, a mold having a fine concavo-convex pattern formed in advance using a processing technique such as semiconductor or MEMS, is pressed or stamped on the surface of the object to be measured 10 to transfer the fine concavo-convex shape, and the concavo-convex region 1 is formed. It may be formed. When the object to be measured 10 is a hard material such as stainless steel that is difficult to engrave, a layer of a relatively soft material such as aluminum is formed on the surface of the object to be measured 10 by vapor deposition or sputtering. The uneven region 1 may be formed by transferring the shape.

  Further, instead of directly forming the uneven region 1 on the surface of the device under test 10, a sheet-like member provided with a fine uneven shape in advance may be attached to the surface of the device under test 10. As this sheet-like member, for example, a nickel plating replica obtained by removing the silicon wafer original plate after nickel plating is applied to the surface of the silicon wafer original plate on which the concavo-convex shape is formed by a semiconductor process. Further, depending on the use environment, a resin material replica having relatively good heat resistance such as polyimide can be used instead of nickel plating.

  Furthermore, although the case where white light having a continuous wavelength distribution is used has been described so far, it is also conceivable to use light such as laser light having a substantially single wavelength instead of white light. In the case of laser light, when the uneven region 1 is irradiated, it is reflected at a specific angle corresponding to the uneven shape. Therefore, it becomes possible to evaluate the deformation amount and the displacement amount of the object to be measured from the angle θ when the position of the light observation unit 3 is adjusted and the laser beam can be observed. Alternatively, when the object to be measured 10 is in a normal shape or position, the light observation unit 3 is fixed at a position where the light reflected from the uneven region 1 can be observed, and an abnormality occurs in the shape or position of the object to be measured 10. In such a case, the presence or absence of an abnormality can be detected by reducing the amount of light reflected from the uneven region 1 or observing it.

  In the present invention, a change in wavelength, that is, a change in color is used. However, since a method for specifically grasping a change in wavelength (= color) can employ many already known methods, The detailed explanation in is omitted. In this specification, the term “wavelength” is used as a comprehensive concept including information such as a color that changes due to a change in wavelength.

  The technique of the patent document described above and the present invention are largely different in the following two points. The first difference is that an uneven area is provided on the object to be measured and this is used as a monitoring target part. The second point is a point paying attention to the color and wavelength of reflected light determined by the deformation and displacement amount of the uneven region. Regarding this point, in the patent document, the change in the amount of light accompanying the change in the proportion of the reflector (the bead in Patent Document 1) or the non-reflector (the black line in Patent Document 2) in the region irradiated with light is evaluated. It is targeted.

  Thereby, the deformation | transformation and displacement of a to-be-measured object can be evaluated by observing the reflection and the scattered light which arise when an uneven | corrugated area | region deform | transforms in connection with a to-be-measured object. In particular, if the amount of deformation of the object to be measured, and the correlation between the amount of displacement and the optical characteristics are known in advance, the amount of deformation can be accurately evaluated without using a highly accurate measuring device. In particular, it can be made less susceptible to the brightness of the surrounding environment.

1: Uneven region 2: Light irradiation unit 3: Light observation unit 4: Determination unit 10: Object to be measured 20: Deformation amount evaluation device

Claims (7)

A structural material deformation amount evaluation device for detecting deformation in the structural material, with the structural material having an uneven area formed on the surface as a measurement object,
From the light irradiation part for irradiating the uneven | corrugated area | region of the surface of the said structural material with light, the light observation part which measures the wavelength of the reflected scattered light reflected and scattered in the said uneven | corrugated area | region, and several light observation results before and behind A determination unit that detects deformation in the structural material using a wavelength difference of the obtained reflected scattered light,
The determination unit is configured to determine an angle of reflected / scattered light that is reflected and scattered by the light irradiation unit to the light observation unit and reflected by the uneven region, and a wavelength of the reflected / scattered light detected by the light observation unit. A structural material deformation amount evaluation apparatus characterized in that a correlation characteristic is held for the uneven regions having a plurality of shapes, and the deformation amount is estimated . The deformation evaluation apparatus for a structural material according to claim 1,
The apparatus for evaluating a deformation amount of a structural material, wherein the light emitted from the light irradiation unit is light having a predetermined wavelength distribution. The deformation evaluation apparatus for a structural material according to claim 1 or 2 ,
An apparatus for evaluating the amount of deformation of a structural material, characterized in that the uneven region directly forms an uneven shape on the surface of the material constituting the object to be measured. The deformation evaluation apparatus for a structural material according to claim 1 or 2 ,
A structural material characterized in that a material layer that is easier to process than the material constituting the object to be measured is provided on the surface of the object to be measured, and the uneven region is formed by forming an uneven shape on the material layer. Deformation amount evaluation apparatus. The deformation evaluation apparatus for a structural material according to claim 1 or 2 ,
An apparatus for evaluating a deformation amount of a structural material, wherein the uneven region is formed by attaching a member formed with an uneven shape in advance to the surface of the object to be measured. The deformation evaluation apparatus for a structural material according to any one of claims 1 to 5 ,
The apparatus for evaluating deformation amount of a structural material, wherein the light observation unit observes at least one of luminance, color, and wavelength distribution of light reflected and scattered by the uneven region. A method for evaluating the amount of deformation of a structural material for detecting deformation in the structural material, with a structural material having an uneven area formed on the surface as a measurement object,
Irradiating light to the concavo-convex region on the surface of the structural material, measuring the wavelength of the reflected scattered light reflected and scattered by the concavo-convex region, and the wavelength difference of the reflected scattered light obtained from a plurality of light observation results before and after thereby detecting the deformation of the structural member using,
Correlation characteristics between the angle of the reflected scattered light when the irradiated light is reflected and scattered by the uneven area and the wavelength of the reflected scattered light are held for the uneven area of a plurality of shapes, and the amount of deformation is A method for evaluating a deformation amount of a structural material, characterized by estimating .

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