JP2008519249A - Gauge for measuring the linear strain of a material and its manufacturing method - Google Patents

Abstract

With respect to a gauge for measuring the linear strain of a material, this gauge is fitted with a measuring blade (2) having axes parallel to each other, at least two measuring elements (1) attachable to the material to be measured, measuring blade A portable scanning body (3) having an impression surface (4) made of a dimensionally stable material having a hardness lower than that of the material of (2). On the side where the measuring element (1) does not face the measuring blade (2), it is placed in the hole (10) of the lug (11) and attached thereto using a resin-based adhesive, the lug (11) It is attached to the surface of the material to be measured using a weld. The method of making the gauge is that the measuring element and lug are placed in a hole in the transfer rig, the blade axes are precisely set parallel to each other, and the adhesive between the measuring element and the lug and the material to be measured An adhesive having a lower hardness is attached to the lug and the measuring element is connected to the material to be measured using the lug.
[Selection] Figure 2

Description

  The present invention relates to a gauge for measuring the linear strain of a material comprising at least two measurement marks created on the material at a distance, and the present invention also relates to a method of making this gauge.

  Mechanical and optical extensometers are used to measure the linear strain of solid materials, especially metals, i.e. to measure the elongation of the material between two fixed points on the structure. As a measuring point, a drawn mark or dent is most often used. The disadvantage of this type of measurement is that if a cut or dent is created, it can damage the material. Some equipment also has the disadvantage that the marks are contaminated with contaminants and are therefore difficult to find. Such extensometers are also used to measure the line strain of materials other than metals, for example, to measure cracks in concrete, etc., within a building. Due to their limited accuracy, such extensometers require a measurement point arrangement on the material or structure with larger spacing. These distances are within a few hundred millimeters.

  A more accurate measurement of the distance between the reference points and the possibility of placing these points close to each other can be achieved by using a measuring microscope. Their main drawback is their relatively large size and weight, so bridges, large diameter pipes and especially when the pipes to be tested are placed in a confined space, for example in a nuclear power plant They cannot actually be used to measure the deformation of existing metallic structural materials such as tubes. Another major problem is that it is difficult to access test locations such as on insulated conduits, drainage conduits inside other structures, and on bridges. The measuring microscope has another drawback that it is easily damaged and its accuracy is easily reduced.

  Various types of tension meters, such as mechanical, optical, electrical, acoustic, and pneumatic, are known. The disadvantages of the mechanical, optical, acoustic and pneumatic tension meters are the same as those of the microscope described above. While electric tensiometers do not have some of the above disadvantages, the major drawback is that they can only operate within a certain temperature range. If the temperature is higher or lower, the electric tensiometers must be adjusted and their acquisition price increases from time to time.

  Another drawback of tensiometers, especially electric tensiometers, is their limited lifetime, which is reduced in proportion to the climatic conditions in which the measurements are made.

  Therefore, with a conventional tensiometer, it is basically impossible to perform outdoor measurements whose results are comparable to the measurement results under laboratory conditions.

  Said defect is lower than the hardness of the material of the measuring blade and / or the portable measuring device according to the invention, fitted with a measuring blade having axes parallel to each other and attachable to the material to be measured It can be solved to some extent by using a gauge for measuring the linear strain of a material provided with a portable scanning body having an impression surface manufactured from a dimensionally stable material having hardness. The essence is that the measuring body is placed in the hole of the lug on the side that does not face the measuring blade and is attached to it using a resin-based adhesive, and the lug uses a weld on the surface of the material to be measured Are connected.

  The lug is advantageously connected to the surface of the material to be measured using a weld made by an electric arc. The lug can be cylindrical and the hole is arranged in the direction of the cylindrical axis and advantageously mates with the internal thread.

  The measuring blade is advantageously provided with a mounting in the central section, and the measuring element can be fitted with the neck and the conical end in the bottom section.

  The measuring element and / or lug is advantageously inserted into a transfer rig comprising a transfer board with holes for the measuring element and / or lug after the axes of the measuring blades have been precisely balanced with each other The joint between the element and / or lug and the transfer rig has a lower strength than the joint between the measuring element and / or lug and the material to be measured.

  The gauge is advantageously measured with the measuring element and / or lug, with the measuring element and / or lug inserted into a hole in the transition preparation, the axis of the blade being precisely set parallel to its mutual distance. So that it is fixed in this position with an adhesive that has a lower strength than the adhesive between it and the measuring element is then connected to the material to be measured with a lug so that the transfer rig can be removed Produced.

  The measuring element is advantageously placed in the hole in the lug before being inserted into the hole in the transfer rig and connected to the lug using a resin-based adhesive, so that the blade axes are parallel to the exact mutual distance. Once set, the lug is welded to the material to be measured and the transport rig is removed.

  In the following advantageous manner, the lugs are welded to the material to be measured, and the measuring elements arranged in the transfer rig are inserted into the lugs and connected to them using a resin-based adhesive, Once the is cured, the transport rig is removed.

  Since the measuring elements are fitted with measuring blades whose axes are parallel to each other, it is possible to measure their exact distance and possibly the bending of the material to be measured. Separate measuring elements on various structures that cannot be connected to other measuring devices in general, such as aircraft structures, power equipment surfaces, etc., by being fixedly connected to the surface of the material to be measured Can be arranged. The material of the impression surface of the scanning body, due to its dimensional stability, allows the impression to be maintained for a long time, thereby allowing the measured material to be monitored and compared over its entire lifetime And Due to the fact that the hardness is lower than the hardness of the material of the measuring element, the measuring element will not wear out even after many measurements.

  Considering the small dimensions of the measuring elements and the materials used for the measuring elements, especially the measuring element materials are difficult to weld or the contact surface is too small, so these measuring elements are connected to the material to be measured It may be difficult to do. However, if the measuring element is placed in the hole of the lug on the side that does not face the measuring blade, it can be connected using a resin-based adhesive, in which case the joint transmits shear and tensile stresses However, its strength is greatly increased. Resin-based adhesives provide a permanent connection even under extreme conditions such as large temperature differences and external influences.

  The lugs are in this case connected to the surface of the material to be measured using a weld, and optimally using a weld that has the least possible influence on the properties of the material to be measured. This particularly refers to a weld made by an electric arc. With current technology, it is possible to produce welds within a few milliseconds, and the necessary equipment is small and light enough to be transported anywhere.

  If the lug is cylindrical, the hole is arranged in the direction of the cylindrical axis, creating a larger contact surface when the hole fits inside the internal thread, and the joint between the measuring element and the lug has a higher strength .

  The measuring blade can have a mounting in its central section, thereby reducing the strength required to produce the impression, between the measuring element and the lug, and between the lug and the material to be measured. The contact area can be reduced. This is because the stress these joints undergo during measurement is smaller. If the measuring element fits in the bottom section with the neck and the conical end, they create a condition that increases the strength of the joint between the measuring element and the lug.

  Since the measuring elements and / or lugs are inserted into the transfer rig after precise setting of each other, the measuring elements can be transported and installed essentially anywhere and measured if the precise settings are maintained. After placing them on the material to be measured, the measuring element and the transfer rig can be easily brought into engagement.

  The gauge fabrication method described above allows the measuring element to be accurately placed in the transfer rig and on the material to be measured, strengthening the joint between the element and the material to be measured, and having a long service life To do.

  According to one method, the measuring element can be first connected to the lug and then the lug can be welded to the material to be measured, and according to another method, the lug is first welded to the material to be measured and then they are Can be fitted to the measuring element. A specific method will be selected based on current needs and possibilities.

  The gauge specified in the present invention enables accurate measurement of permanent material deformation on the section to be measured by using a highly precise measuring instrument such as a measuring microscope. This large and heavy device cannot be installed directly on a bridge, pipeline, ship, or other structure whose condition must be monitored after an excessive load, such as an earthquake, is applied. It is therefore advantageous to use a gauge according to the invention in which the measurement of the distance between measuring elements before and after being loaded is carried out with a measuring microscope on the impressions of the measuring points produced on the collected impression bodies. Become.

  The present invention will be described in more detail with respect to specific embodiments using the accompanying drawings.

  An exemplary linear strain gauge for a material comprises at least two measuring elements 1 that mate with a measuring blade 2 having parallel axes. These measuring elements 1 can be attached to the material to be measured. The gauge also comprises a portable scanning body 3 having an impression surface 4 made of a dimensionally stable material having a lower hardness than the material of the measuring blade 2, or the scanning body 3 is replaced by a portable measuring device Or it can be complemented. On the side not facing the measuring blade 2, the measuring element 1 is placed in the hole 10 of the lug 11 and attached thereto using a resin-based adhesive. The lug 11 has a cylindrical shape, and the hole 10 is disposed in the direction of the cylindrical axis and fits with the female screw portion 12. The lug 11 is attached to the surface of the material to be measured using a weld made by an electric arc.

  The measuring blade 2 has a mounting part 5 in its central section, and the measuring element 1 fits with the neck 6 and the conical end 7 in its bottom section.

  Following the precise setting of the axes of the measuring blade 2 parallel to each other, the measuring element 1 is inserted into a transfer rig 8 including a transfer board having a hole 9 for the measuring element 1, and the measuring element 1 and the transfer The joint between the rigs 8 has a lower strength than the joint between the measuring element 1 and the material to be measured.

  The gauge is manufactured so that the measuring element 1 is inserted into the hole 9 in the rig 8 and the exact mutual distance and parallelism of the axis of the blade 2 are set, after which the measuring element 1 is measured with the measuring element 1. It is fixed in this position using an adhesive having a lower strength than the adhesive used with the adhesive material. Thereafter, the measuring element 1 is attached to the material to be measured with a lug 11 and the transfer rig 8 can be removed after the measuring element 1 is connected.

  According to one method, the measuring element 1 is placed in the hole 10 of the lug 11 before being inserted into the hole 9 in the transfer rig 8 and connected to the lug 11 using a resin-based adhesive, After setting the exact distance and parallelism of the axis of the blade 2, the lug is welded to the material to be measured and the transfer rig 8 is removed.

  According to another method, the lugs 11 are first welded to the material to be measured and the measuring element 1 arranged in the transfer rig 8 is inserted into the lug 11 and attached to them using a resin-based adhesive. Connected. When the joint is cured, the transport rig 8 is removed.

  In the case of a method for measuring the permanent line strain of a material, where the change in the original distance between two points on the surface of the material is confirmed, the impression of the measuring element 1 fixed on the surface of the material to be measured is scanned. The exact distance of the confirmed position of both impressions produced on the impression surface 4 of the body 3 is measured within the spacing of the measuring element 1 and a first pair of impressions is produced before the strain, measuring element 1 Another pair of impressions is produced after the critical strain, and the distance between the first pair of impressions and the second pair of impressions is compared. The gauge thus comprises a fixed part attached to the section of material to be measured and a portable part.

  The gauge for measuring the linear strain of a material and the manufacturing method thereof according to the present invention can be applied to various industrial fields such as outer space, ships, electric power, and construction.

It is a top view which shows the position of two measurement elements. FIG. 4 is a side cross-sectional view of a measuring element in a lug with an impression body.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Measuring element, 2 ... Measuring blade, 3 ... Scanning body, 4 ... Impression surface, 8 ... Rig, 11 ... Lug

Claims (8)

  At least two measuring elements (1), which fit into a measuring blade (2) having axes parallel to each other and are attachable to the material to be measured, have a hardness lower than the hardness of the material of said measuring blade (2) A portable scanning body (3) having an impression surface (4) made of a dimensionally stable material and / or a portable measuring device, the measuring element (1) not facing the measuring blade (2) A material which is placed in the hole (10) of the lug (11) on the side and attached thereto using a resin-based adhesive, said lug (11) being attached using welding to the surface of the material to be measured Gauge for measuring the line strain.   Gauge according to claim 1, characterized in that the lug (11) is attached to the surface of the material to be measured using a weld made by an electric arc.   Gauge according to claim 1 or 2, characterized in that the lug (11) is cylindrical and the hole (10) is arranged in the direction of the cylinder axis and fits with an internal thread (12).   The measuring blade (2) has a mounting part (5) in its central section, and the measuring element (1) fits in the bottom section with the neck (6) and the conical end (7). The gauge according to any one of claims 1 to 3, which is characterized.   After the measuring element (1) and / or the lug (11) has precisely set the mutually parallel axes of the measuring blade (2), holes for the measuring element (1) and the lug (11) ( 9) is inserted into a transfer rig (8) formed by a transfer board having a measuring board (1) and / or a joint between the lug (11) and the transfer rig (8) Gauge according to any one of the preceding claims, characterized in that it has a lower strength than the joint between the element (1) and / or the lug (11) and the material to be measured.   The measuring element and / or lug is inserted into a hole in a transfer rig, the blade axes are set parallel with a precise mutual distance, and between the measuring element and / or the lug and the material to be measured It is fixed in this position using an adhesive having a lower strength than the adhesive, after which the measuring element is connected to the material to be measured using the lug and the transfer rig is removable. The manufacturing method of the gauge as described in any one of Claims 1-5.   The measuring element is placed in the lug hole before being inserted into the hole in the transfer rig and attached to the lug using a resin-based adhesive, and the blade axis is placed at a precise mutual distance. The method according to claim 6, characterized in that, after setting in parallel, the lug is welded onto the material to be measured and the transfer rig is removed.   The lug welded to the material to be measured and the measuring element arranged in the transfer rig are then inserted into the lug and connected to them using a resin-based adhesive, the joint being The method of claim 6, wherein upon curing, the transfer rig is removed.

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