JP2008111739A - Tool for thickness-wise shear test on sheet-like material and thickness-wise shear test machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tool for a thickness-wise shear test used in a thickness-wise shear test machine on a sheet-like material and the thickness-wise shear test machine equipped therewith. <P>SOLUTION: This tool comprises first and second hold members holding a test piece made of a sheet material from its front and rear sides, respectively, along its plane direction. By relatively moving the first and second hold members parallel to each other along the prescribed plane direction, parallel forces are caused to act on the test piece in directions opposite to each other to thickness-wise shear-deform the sheet-like material. The directions of the parallel forces are constant before and after the thickness-wise shear deformation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a jig for a thickness direction shear test used in a thickness direction shear test machine for a sheet-like material, and a thickness direction shear test machine including the jig.

  In a situation where a sheet-like material such as paper or a product made of a sheet-like material is actually used, the material and the product often receive shear stress in the thickness direction. Therefore, when optimizing the design of paper or paper products from an engineering standpoint, it is necessary to quantitatively grasp the shear characteristics in the thickness direction of the paper. Furthermore, when the sheet material exceeds the elastic region and receives a load after the plastic region, it is necessary to take into account not only the elastic properties but also the plastic properties. Therefore, it is considered to measure a thickness direction shear stress-thickness direction strain curve while causing a thickness direction shear deformation of the sheet material.

  However, in general, it is difficult to create a pure shear stress state in the test area, and in particular, it is difficult to hold a sheet-like material from the front and back along the plane direction. There are currently few laws. In the field of paper, there is a method in which the front and back sides of a rectangular test piece are bonded to a metal block, and a parallel force in the opposite direction is applied to the metal block along the plane direction of the test piece (Non-Patent Document 1, 2). FIG. 7 shows a jig for thickness direction shear test of a sheet-like material described in Non-Patent Document 2.

Tappi / October 1975 Vol. 58, No. 10 (132-135 pages) Svensk Papperstidning Nr 3 1977 (p. 89-93)

However, since the jigs shown in Non-Patent Documents 1 and 2 change the direction of each metal block and the direction of the parallel force acting on the test piece with the shear deformation in the thickness direction of the rectangular test piece, There is a problem that it becomes difficult to measure the deformation amount of the directional shear and the shearing force in the thickness direction.
The present invention has been made by paying attention to the above-described prior art, and is capable of accurately and simply measuring the thickness direction shear characteristics of a sheet-like material such as paper or film. An object of the present invention is to provide a directional shear measurement jig and an in-plane shear test machine using the same.

  1st form of this invention is the jig for thickness direction shearing tests of a sheet-like material, Comprising: The 1st, 2nd holding member which hold | maintains the test piece which consists of the said sheet material from each front and back along a plane direction And by causing the first holding member and the second holding member to relatively translate along the predetermined plane direction, a parallel force is applied to the test piece in the opposite direction. The sheet material is subjected to shear deformation in the thickness direction, and the direction of the parallel force is constant before and after the thickness direction shear deformation.

  According to a second aspect of the present invention, the first holding member is held by a first jig body, the second holding member is held by a second jig body, and each jig body is It is characterized by moving parallel to each other along a predetermined plane direction.

  In the third aspect of the present invention, the first and second guide bars are respectively fixed to the first and second jig bodies, and the first jig body is attached to the second guide bar. The two jig bodies can be translated in parallel with each other along the predetermined plane direction while being guided by the first guide bars.

  According to a fourth aspect of the present invention, the first holding member and the second holding member in the predetermined plane direction are respectively attached to the first and second jig bodies or the members that move together with the jig body. A displacement measuring member for measuring a relative displacement amount is provided.

According to a fifth aspect of the present invention, there is provided the thickness direction shear test jig for the sheet-like material according to any one of claims 1 to 4, and the thickness direction shear of the test material held by the jig. A thickness direction shear tester for performing a test,
A load means for applying a load in a direction in which the first holding member and the second holding member are relatively translated, and a load measurement for measuring the load applied to the test piece by the load means with time. And a displacement amount measuring means for measuring a relative displacement amount of the first holding member and the second holding member in the predetermined plane direction as time elapses.

  In the thickness direction shear measuring jig and the thickness direction shear measuring machine using the same according to the present invention, the reverse parallel force applied to the test piece by the first and second holding members is the thickness. Since there is no change before and after the directional shear deformation, it becomes possible to easily and accurately measure the thickness direction shear characteristics such as the deformation amount and the thickness direction shear force of the sheet-like material. Furthermore, since the thickness direction shearing jig can be used by being attached to a general-purpose material testing machine or the like, the equipment cost can be reduced as compared with the case where a dedicated machine is provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, a thickness direction shear test jig according to an embodiment of the present invention will be described with reference to FIGS. 1 is an exploded front view of the thickness direction shear test jig according to the embodiment of the present invention, and FIG. 2 is an overall view of the thickness direction shear test jig formed by combining those shown in FIG. It is a figure which shows a structure, (a) is a front view, (b) is a side view.

  In this embodiment, as a first and second holding member for holding a test piece made of a sheet material from the front and back sides along the plane direction, JAPAN TAPPI NO. A metal block (shown in FIG. 3) based on the internal bond strength test method (Z-axis direction tensile test method) of paper and paperboard standardized in 18-1. Although the present invention is not limited to this, as the first and second holding members in the present invention, JAPAN TAPPI NO. By using the same metal block based on the internal bond strength test method of paper and paperboard standardized in 18-1, in the thickness direction shear test of the sheet-like material and the internal bond strength test The holding member can be shared. Accordingly, there is an effect that it is easy to perform the two tests continuously or simultaneously by sampling the test pieces used for the two tests together.

  As shown in FIGS. 1 and 2, the jig 1 according to the present embodiment includes a moving side jig 10 and a fixed side jig 20. The movement side jig 10 mainly includes a movement side jig body 11, a movement side holding member 12 that holds the surface of a rectangular test piece made of a sheet material, a movement side holding member 13 that holds the movement side holding member 12, A moving side guide bar 14 having one end fixed to the moving side jig main body 11 and a joint 15 for attaching the moving side jig main body 11 to a material testing machine described later are provided.

  Further, as shown in FIG. 4, the moving side holding member 13 that holds the moving side holding member 12 positions the push pin 41 penetrating the moving side holding member 13 so as to move downward by the tip taper screw 42. The movable holding member 12 can be fixed by the push pin 41. 4 shows the structure of the fixed-side holding member 23, the replacement of the fixed-side holding member 23 with the moving-side holding member 13 is the same structure except that the upside down is reversed.

  On the other hand, the fixed-side jig 20 includes a fixed-side jig body 21, a fixed-side holding member 22, a fixed-side holding member 23, a fixed-side guide bar 24, a joint 25, and the like, like the moving-side jig 10. , And arranged at a position rotated 180 degrees with respect to the moving side jig 10.

  Further, a guide hole 11 a for inserting the guide bar 24 is formed in the movement side jig main body 11 of the movement side jig 10. Further, a guide hole 21 a for inserting the guide bar 14 is formed in the fixed-side jig main body 21 of the fixed-side jig 20. Then, the guide bar 14 of the moving jig 10 is inserted into the guide hole 21a of the fixed jig 20, and the guide bar 24 of the fixed jig 20 is inserted into the guide hole 11a of the fixed jig 10, respectively. As shown in FIG. 2, the movable jig 10 and the fixed jig 20 are combined so that they can move linearly along two guide bars 14 and 24 that are parallel to each other.

  Thus, since the movement side jig | tool 10 and the fixed side jig | tool 20 move along the guide bars 14 and 24, both jig | tool 10 and 20 move on the same plane, without producing a twist. In the present embodiment, both the guide bars 14 and 24 have a circular cross-sectional shape, and the guide holes 21a and 11a through which the guide bars 14 and 24 are inserted are each constituted by a rolling bearing. Therefore, the frictional resistance between the guide bars 14 and 24 and the guide holes 21a and 11a is suppressed to a small value that can be ignored with respect to the load during the test.

  FIG. 3 shows a JAPAN TAPPI NO. Used as first and second holding members for holding a test piece made of a sheet material from the front and back sides in a plane direction. It is a figure which shows the metal block based on the internal bond strength test method (Z-axis direction tensile test method) of the paper and paperboard which are standardized by 18-1, (a) is a front view, (b) is a side view. It is.

  FIG. 6 is a diagram illustrating a displacement measuring unit 32 for detecting a change in relative displacement between the moving-side jig 10 and the fixed-side jig 20. The displacement measuring unit 32 includes a pin (displacement measuring member) 16 protruding from the holding member 13 of the moving side jig 10 and a pin (displacement measuring) protruding from the fixed side jig main body 21 of the fixed side jig 20. Member) 26. When testing by applying a tensile force to the jig, in the initial state where the moving side jig 10 and the fixed side jig 20 are combined as shown in FIG. 2 and FIG. A predetermined interval is set between the pins 16 and 26 as the moving side jig 10 is separated from the fixed side jig 20. The relative displacement between the moving side jig 10 and the fixed side jig 20 is detected by detecting this distance by a sensor provided in a thickness direction shear tester described later.

  A test piece T obtained by cutting a sheet material into a rectangle is used for the thickness direction shear test jig 1 configured as described above. In order to hold the test piece T on the moving side holding member 12 and the fixed side holding member 22 in the jig 1 for in-plane shear test, a double-sided adhesive tape or an adhesive is used. When it is necessary to accurately measure the shear deformation in the thickness direction of the sheet-like material, it is desirable to use an adhesive.

  After the test piece T is fixed as described above, when a load is applied in a direction in which the moving side joint 15 and the fixed side joint 25 are separated from each other, the test piece T fixed to both the holding members 12 and 22 is relatively moved. A parallel force (load) in the opposite direction is applied, and the specimen T undergoes shear deformation in the thickness direction. At this time, since both the holding portions 12 and 22 move in parallel in the same plane without twisting, the test area of the test piece T is displaced from the plane, or both the holding members 12 and 22 rotate and the test piece T Thus, a shear stress in the thickness direction close to a pure shear stress can be generated without generating a moment.

  In addition, since the direction of the parallel force applied to the test piece T is always constant with respect to the load direction applied to both the joints 15 and 25, the shear stress and strain in the thickness direction can be easily changed by the amount of displacement of both holding members 12 and 22. Can be calculated.

  Furthermore, the thickness direction shear test jig 1 in the present embodiment is mounted on a general material testing machine used for tension, compression, etc., so that the load (parallel) in the thickness direction shear test of the sheet-like material. Power). Accordingly, if the jig 1 for the thickness direction shear test is removed, the testing machine main body 31 can be shared for tensile and compression tests other than the sheet material, and a testing machine dedicated to the thickness direction shear test for the sheet material is installed. Compared to the case, the equipment cost can be greatly reduced.

(Thickness direction shear stress tester)
Next, an embodiment of a thickness direction shear test machine using the thickness direction shear test jig 1 will be described with reference to FIGS.

  The thickness direction shear tester 30 shown in FIG. 5 is provided with a movable portion 33 that is moved up and down by a lift mechanism (not shown) provided on both sides of the tester main body 31. A load cell 34 is provided at the center of the movable portion 33. The load cell 34 is connected to the moving joint 15 of the jig 1, and the bottom 35 of the tester main body 31 is connected to the fixed joint 25 of the jig 1. The load cell 34 detects the load applied to the movable part 33 with the passage of time.

  The structure of the raising / lowering mechanism, the movable part 33, the load cell 34, etc. in the test machine main body 30 shown in FIG. However, the shear displacement in the thickness direction of the sheet-like material to be tested is very small and is required to be measured with high accuracy. Therefore, in the thickness direction shear tester in the present embodiment, the relative displacement amount of the moving side jig 10 with respect to the fixed side jig 20 is set as the displacement amount of the test piece, and as shown in FIG. The distance interval between the two pins 16 and 26 attached to the fixed jig 20 is measured by a non-contact type displacement sensor 38 as time elapses. On the other hand, the normal material testing machine measures the displacement of the test piece by the calculation formula of “moving speed × time”, so the accuracy is poor, and therefore the measurement is performed using the displacement sensor 38 as in the present embodiment. It is preferable.

  The displacement sensor 38 includes a light emitting unit 39 that emits light (laser light or the like) and a light receiving unit 40 that receives light (laser light or the like) emitted from the light emitting unit 39, both of which are tester main bodies 31. It is fixed on the support stand 36 attached to the bottom part 35 of this. Within the range from the light emitting unit 39 to the light receiving unit 40, a position blocked by the two pins 16 and 26 (see FIG. 6) provided on the jig 1, that is, a non-light receiving position by the light receiving unit 40 is detected. The distance between the pins 16 and 26 is detected by detecting the distance between the non-light receiving positions. In this embodiment, a high-speed, high-precision digital dimension measuring instrument LS-7010 manufactured by Keyence Corporation is used as the displacement sensor.

Next, the thickness direction shear test method of the sheet-like material by the thickness direction shear tester 30 of the present embodiment and the result thereof will be described.
In the thickness direction shear test using the testing machine 30, a rectangular test piece T is fixed to the jig 1 mounted on the testing machine body 31 as shown in FIG. Thickness direction shear deformation was generated in the test piece T by applying a load (tensile force) in the upward direction to the movable portion 33 of the test machine body 31 by the lifting mechanism. Further, the load cell 34 provided in the movable portion 33 of the tester main body 31 detected a change with time of the shearing load in the thickness direction applied to the test piece T. Furthermore, the displacement of the test piece T was measured using the above-mentioned displacement sensor (High-speed / high-precision digital dimension measuring device LS-7010 manufactured by Keyence Corporation).

  FIG. 8 shows an example of a curve obtained by plotting the thickness direction shear load data and the thickness direction shear displacement data measured using the thickness direction shear tester 30 against time. Here, the tensile speed is 2 mm / min, and the test piece is white paperboard.

FIG. 9 is an example of a thickness direction shear stress-thickness direction strain curve obtained from the thickness direction shear load data and the thickness direction shear displacement data of FIG. In FIG. 9, the vertical axis represents the thickness direction shear stress (MPa), and the horizontal axis represents the thickness direction shear strain. The thickness direction shear stress and the thickness direction shear strain are given by the following equations, respectively.
Thickness direction shear stress = Thickness direction shear load / Test piece area Thickness direction shear strain = Thickness direction shear displacement / Specimen thickness

  As described above, in the thickness direction shear measuring jig 1 according to the present embodiment and the thickness direction shear test machine 30 using the same, both sides of the test piece T made of a sheet-like material are fixed and moved. The test piece T is shear-deformed in the thickness direction by applying parallel forces having different directions along each holding member, and the time change of the load and displacement generated in the test piece T is measured. At this time, since the direction of the parallel force does not change before and after shear deformation in the thickness direction of the test piece T, it is possible to easily measure the displacement and force in the direction in which the parallel force acts. Accurate thickness direction shear stress-thickness direction strain characteristics of the test piece T that could not be measured easily can be obtained.

  Further, the thickness direction shear stress-thickness direction strain characteristic obtained by the testing machine of this embodiment is a numerical analysis such as a finite element method for design optimization of a sheet-like material such as paper or a product made of a sheet-like material. It can be used as a material characteristic value when considering based on a technique, and is extremely useful.

  In the above embodiment, the thickness direction shear test jig 1 is constituted by the moving side jig 10 (first holding member) and the fixed side jig 20 (second holding member). Although only the movement-side jig 10 is moved, it is also possible to fix the first holding member and move the second holding member. Further, the thickness direction shear test machine 30 has a vertical configuration in which the movable part 33 is moved up and down, but the movable part is moved in the horizontal direction to apply a load to the thickness direction shear test jig 1. It is also possible to take a horizontal configuration.

  Further, in the thickness direction shear tester 30 in the above embodiment, light (laser light or the like) is used as a displacement measuring means for measuring the relative displacement in the linear direction between the first holding member and the second holding member. Although the displacement sensor provided with the light projecting / receiving unit is used, other displacement sensors may be used as long as the displacement of the first holding member and the second holding member can be detected with high accuracy.

It is a front view which decomposes | disassembles and shows the thickness direction shear jig | tool in embodiment of this invention. It is a figure which shows the whole structure of the jig | tool for thickness direction shear tests which combines what was shown in FIG. 1, (a) is a front view, (b) is a side view. JAPAN TAPPI NO. Used as first and second holding members for holding a test piece made of a sheet material from the front and back sides along the plane direction. It is a figure which shows the metal block based on the internal bond strength test method (Z-axis direction tensile test method) of the paper and paperboard which are standardized by 18-1, (a) is a front view, (b) is a side view. It is. It is a figure which shows the structure of the fixed side clamping member which clamps a fixed side holding member in the jig | tool for thickness direction shear tests shown in FIG. 2, (a) is a front view, (b) is a side view. It is a figure which shows one Embodiment of the thickness direction shear test machine using the jig | tool for thickness direction shear tests shown in FIG. 1, (a) is a front view, (b) is a side view. FIG. 6 is a detailed view showing two pin portions detected by a displacement sensor of the thickness direction shear tester shown in FIG. 5, wherein (a) is a front view and (b) is a side view. It is a figure which shows the jig | tool for the thickness direction shear test of the conventional sheet-like material described in the nonpatent literature 2. FIG. FIG. 6 is a diagram showing an example of a curve obtained by plotting the thickness direction shear load data and the thickness direction shear displacement data measured using the thickness direction shear test machine shown in FIG. 5 against time. It is a diagram which shows an example of the thickness direction shear stress-thickness direction shear strain curve calculated | required from the thickness direction shear load data and thickness direction shear displacement data shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Jig 10 Movement side jig 11 Movement side jig main body 12 Movement side holding member 13 Movement side holding member 14 Movement side guide bar 15 Movement side joint 16 Pin 20 Fixed side jig 21 Fixed side jig main body 22 Fixed side Holding member 23 Fixed side holding member 24 Fixed side guide bar 25 Fixed side joint 26 Pin 30 Thickness direction shear tester 31 Tester main body 32 Displacement measuring part 33 Movable part 34 Load cell 35 Bottom part 36 of tester main body Projecting part and Light receiving unit mounting base 38 Displacement sensor 39 Light projecting unit 40 Light receiving unit 41 Push pin 42 Tapered tip

Claims (5)

A jig for shear test in the thickness direction of a sheet material,
Having first and second holding members for holding the test piece made of the sheet material from the front and back sides along the plane direction;
By causing the first holding member and the second holding member to relatively translate along the predetermined plane direction, a parallel force is applied to the test piece in the opposite direction to thereby change the sheet-like material. A jig for thickness direction shear test of a sheet-like material, wherein the jig is subjected to shear deformation in the thickness direction, and the direction of the parallel force is constant before and after the thickness direction shear deformation.   The first holding member is held by a first jig body, the second holding member is held by a second jig body, and the jig bodies are parallel to each other along the predetermined plane direction. The jig for thickness direction shear test of the sheet-like material according to claim 1, wherein   First and second guide bars are fixed to the first and second jig bodies, respectively, the first jig body is the second guide bar, and the second jig body is the first The jig for thickness direction shear test of a sheet-like material according to claim 1 or 2, wherein the jig can be translated in parallel with each other along the predetermined plane direction while being guided by guide bars.   In order to measure the relative displacement in the predetermined plane direction between the first holding member and the second holding member on each of the first and second jig bodies or the members moving together therewith. 4. A jig for thickness direction shear test of a sheet-like material according to claim 1, wherein a displacement measuring member is provided. A thickness direction shear tester comprising the thickness direction shear test jig for a sheet-like material according to any one of claims 1 to 4, wherein the thickness direction shear test is performed on the test material held by the jig. Because
A load means for applying a load in a direction to relatively translate the first holding member and the second holding member;
Load measuring means for measuring the load applied to the test piece by the load means as time passes;
Displacement amount measuring means for measuring the relative displacement amount of the first holding member and the second holding member in the predetermined plane direction with the passage of time. Thickness direction shear tester.

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