Auxiliary tool for pasting strain gauge

Abstract

The utility model discloses an auxiliary tool for pasting a strain gauge, and the tool comprises a positioning plate which is provided with a first technology edge matched with a first positioning edge of a test piece, a second technology edge matched with a second positioning edge of the test piece, and a strain gauge pasting position matched with the size of the strain gauge. The distance between the center of the strain gauge pasting position and the first process edge meets a set first distance; and the distance between the center of the strain gauge pasting position and the second process edge meets a set second distance. According to the utility model, the measuring steps can be saved, the test result is prevented from being influenced by damage to the test piece in the measuring and scribing process, and the pasting precision and pasting efficiency of the strain gauge are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of composite material testing, and particularly relates to an auxiliary tool for pasting strain gauges. Background Art

[0002] The post-impact compression test is an important means to measure the damage impedance and damage tolerance of composite materials, and this test is widely used in the aviation industry to evaluate the toughness of resin-based materials. To ensure the accuracy and effectiveness of the damage impedance test performance of composite materials, it is necessary to avoid the influence of bending force on the composite material test piece during the compression process. To evaluate whether the composite material test piece is bent during the test, two strain gauges should be symmetrically pasted on each side at a position 25 mm away from the upper edge and side edge of the test piece (size: 150*100 mm) to measure the bending percentage.

[0003] Currently, when conducting the post-impact compression test, the positioning method for pasting strain gauges on the test piece mainly uses a method of measuring the distance with a caliper and drawing cross positioning lines with the tip of the caliper. This method has many drawbacks, including: ① Measuring requires adjusting the caliper, and the process is cumbersome; ② For those without caliper operation experience, it is easy to make adjustment errors; ③ When measuring with a caliper, misalignment of the edges will cause measurement errors; ④ Drawing lines with the tip of the caliper is likely to damage the surface state of the test piece, risking affecting the test results, etc. Summary of the Invention

[0004] The purpose of the utility model is to provide an auxiliary tool for pasting strain gauges, which can save the measurement steps, avoid damaging the test piece during the measurement and scribing processes, thereby affecting the test results, and improve the pasting accuracy and pasting efficiency of the strain gauges.

[0005] To achieve the above purpose, the technical solution adopted by the utility model is:

[0006] In the first aspect, an auxiliary tool for pasting strain gauges is provided, including: a positioning plate, the positioning plate has a first process edge matching the first positioning edge of the test piece, a second process edge matching the second positioning edge of the test piece, and a strain gauge pasting position for pasting the strain gauge on the surface of the test piece and matching the size of the strain gauge; the distance between the center of the strain gauge pasting position and the first process edge satisfies a set first spacing; the distance between the center of the strain gauge pasting position and the second process edge satisfies a set second spacing.

[0007] Further, a first limit card matching the first positioning edge of the test piece is arranged on the first process edge.

[0008] Further, a second limit card matching the second positioning edge of the test piece is arranged on the second process edge.

[0009] Further, one side of the strain gauge pasting position is of an open design.

[0010] Further, the positioning plate has a first surface that fits the surface of the test piece, and a pressing auxiliary surface for assisting in pressing the strain gauge is provided on the second surface opposite to the first surface.

[0011] Further, the distance between the pressing auxiliary surface and the first surface is less than the thickness of the strain gauge.

[0012] Further, the area of the pressing auxiliary surface is larger than the area of the strain gauge pasting position, and the center of the pressing auxiliary surface coincides with the center of the strain gauge pasting position.

[0013] Further, positioning auxiliary lines for assisting in positioning the strain gauge are provided on the pressing auxiliary surface.

[0014] In a second aspect, a method for pasting a strain gauge is provided. Using the strain gauge pasting auxiliary tooling described in the first aspect, the method includes: aligning the first process edge of the positioning plate with the first positioning edge of the test piece; aligning the second process edge of the positioning plate with the second positioning edge of the test piece; and pasting the strain gauge on the strain gauge pasting position of the positioning plate.

[0015] Compared with the prior art, the beneficial effects achieved by the present utility model are as follows: The present utility model provides a first process edge on the positioning plate that matches the first positioning edge of the test piece, a second process edge that matches the second positioning edge of the test piece, and a strain gauge pasting position that matches the size of the strain gauge; the distance between the center of the strain gauge pasting position and the first process edge meets a set first spacing; the distance between the center of the strain gauge pasting position and the second process edge meets a set second spacing; this saves the measurement steps during the strain gauge pasting process, avoids damage to the test piece during the measurement and scribing processes, which may affect the test results, and improves the pasting accuracy and efficiency of the strain gauge. Description of the Drawings

[0016] Figure 1 is a schematic plan view of a composite material test piece used in an embodiment of the present utility model Figure 1 ;

[0017] Figure 2 is a schematic plan view of a composite material test piece used in an embodiment of the present utility model Figure 2 ;

[0018] Figure 3 is a schematic structural diagram of a strain gauge pasting auxiliary tooling provided by an embodiment of the present utility model;

[0019] Figure 4It is a schematic diagram of pasting a strain gauge on a test piece using an auxiliary tool for pasting a strain gauge provided by an embodiment of the present invention;

[0020] In the figure: 10, the second surface; 11, the first process edge; 111, the first limit card; 12, the second process edge; 121, the second limit card; 13, the strain gauge pasting position; 131, the pressing auxiliary surface; 132, the positioning auxiliary line; 20, the strain gauge; a, the first positioning edge; b, the second positioning edge; x, the second spacing; y, the first spacing. Detailed implementation manners

[0021] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0022] The present invention explains the structure and usage method of the auxiliary tool for pasting a strain gauge through the process of pasting a strain gauge on a composite material test piece during the post - impact compression test of the composite material.

[0023] As Figure 1 shown, the post - impact compression test of the composite material requires pasting two strain gauges 20 symmetrically on each side at a position 25 mm away from the upper edge (the first positioning edge a) and the side edge (the second positioning edge b) of the composite material test piece (size: 150 * 100 mm) to measure the bending percentage. The calculation method of the bending percentage is shown in formula (1). Generally, it is considered that the test is valid when the bending percentage is less than 10% during the test process.

[0024] Bending percentage = (1)

[0025] Among them, represents the indicated strain of the strain gauge on one surface, represents the indicated strain of the strain gauge on the back surface.

[0026] Currently, the positioning method for pasting a strain gauge on a post - impact compression test piece is mainly to measure the distance using a caliper and draw a cross - shaped positioning line with the tip of the caliper. As Figure 2 shown. This method has many drawbacks, so an auxiliary tool for pasting a strain gauge is specially designed.

[0027] Embodiment 1:

[0028] As Figure 3 、 Figure 4As shown in the figure, a strain gauge pasting auxiliary tooling includes a positioning plate. The positioning plate has a first process edge 11 that matches the first positioning edge a of the composite material test piece, a second process edge 12 that matches the second positioning edge b of the composite material test piece, and a strain gauge pasting position 13 for pasting the strain gauge on the surface of the test piece and matching the size of the strain gauge. The distance between the center of the strain gauge pasting position 13 and the first process edge 11 meets the set first spacing y (y = 25 mm, and y can also be other sizes required by the test). The distance between the center of the strain gauge pasting position 13 and the second process edge 12 meets the set second spacing x (x = 25 mm, and x can also be other sizes required by the test). It should be noted that the center of the strain gauge pasting position 13 coincides with the center of the pasted strain gauge.

[0029] During use, first align the first process edge 11 of the positioning plate with the first positioning edge a of the composite material test piece; then align the second process edge 12 of the positioning plate with the second positioning edge b of the composite material test piece; then, paste the strain gauge at the strain gauge pasting position 13 of the positioning plate. To prevent the tooling from adhering to the composite material test piece during the strain gauge pasting process, the tooling can be treated with anti-adhesion.

[0030] In the present utility model, the first spacing y and the second spacing x are obtained by processing according to the actual experimental requirements, saving the measurement steps during the strain gauge pasting process, avoiding damage to the test piece during the measurement and scribing processes, which may affect the test results, and improving the pasting accuracy and pasting efficiency of the strain gauge.

[0031] Embodiment 2:

[0032] Based on Embodiment 1, this embodiment adds the following settings: a first limit card 111 that matches the first positioning edge a of the composite material test piece is provided on the first process edge 11, or a second limit card 121 that matches the second positioning edge b of the test piece is provided on the second process edge 12, or a first limit card 111 that matches the first positioning edge a of the composite material test piece is provided on the first process edge 11, and a second limit card 121 that matches the second positioning edge b of the test piece is provided on the second process edge 12.

[0033] During use, press the first limit card 111 tightly against the first positioning edge a of the composite material test piece, and the first process edge 11 of the positioning plate can be aligned with the first positioning edge a of the composite material test piece. Press the second limit card 121 tightly against the second positioning edge b of the composite material test piece, and the second process edge 12 of the positioning plate can be aligned with the second positioning edge b of the composite material test piece.

[0034] In this embodiment, by providing the first limit card 111 and / or the second limit card 121, the alignment speed and accuracy between the first process edge 11 of the positioning plate and the first positioning edge a of the composite material test piece can be improved; the alignment speed and accuracy between the second process edge 12 of the positioning plate and the second positioning edge b of the composite material test piece can be improved; and thus, the pasting speed of the strain gauge can be increased.

[0035] Embodiment 3:

[0036] Based on the strain gauge pasting auxiliary tooling described in Embodiment 1 and Embodiment 2, this embodiment further includes the following settings: One side of the strain gauge pasting position 13 is of an open design, which is convenient for taking and placing the strain gauge during the pasting of the strain gauge and facilitates operation.

[0037] Furthermore, the positioning plate has a first surface that fits the surface of the composite material test piece, and a pressing auxiliary surface 131 for assisting in pressing the strain gauge is provided on the second surface 10 opposite to the first surface. The distance between the pressing auxiliary surface 131 and the first surface is less than the thickness of the strain gauge. When installing the strain gauge, it is convenient to apply pressure to the strain gauge to ensure that the strain gauge can be firmly pasted on the composite material test piece.

[0038] Furthermore, the area of the pressing auxiliary surface 131 is larger than the area of the strain gauge pasting position 13, and the center of the pressing auxiliary surface 131 coincides with the center of the strain gauge pasting position 13, which can further improve the pasting accuracy of the strain gauge.

[0039] Furthermore, positioning auxiliary lines 132 for assisting in positioning the strain gauge are provided on the pressing auxiliary surface 131, and the positioning auxiliary lines 132 are used to align with the cross lines of the strain gauge. When the positioning auxiliary lines 132 are provided, the intersection point of each positioning auxiliary line 132 is the center of the pasted strain gauge; at this time, the center of the strain gauge pasting position 13 and the center of the pasted strain gauge may not coincide; the first distance y refers to the distance between the first process edge 11 and the corresponding positioning auxiliary line 132; the second distance x refers to the distance between the second process edge 12 and the corresponding positioning auxiliary line 132.

[0040] Embodiment 4:

[0041] Based on the strain gauge pasting auxiliary tooling described in Embodiments 1 to 3, this embodiment provides a strain gauge pasting method, including: aligning the first process edge 11 of the positioning plate with the first positioning edge a of the test piece; aligning the second process edge 12 of the positioning plate with the second positioning edge b of the test piece; and pasting the strain gauge on the strain gauge pasting position 13 of the positioning plate.

[0042] The above are only the preferred embodiments of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present utility model, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present utility model.

Claims

1. A strain gauge pasting auxiliary tool, characterized in that: include: A positioning plate, the positioning plate having a first process edge (11) for aligning with a first positioning edge (a) of the test piece, a second process edge (12) for aligning with a second positioning edge (b) of the test piece, and a strain gauge pasting position (13) for pasting the strain gauge on the surface of the test piece and having the same size as the strain gauge; The distance between the center of the strain gauge pasting position (13) and the first process edge (11) satisfies a set first spacing (y); the distance between the center of the strain gauge pasting position (13) and the second process edge (12) satisfies a set second spacing (x); A first limiting card (111) is provided on the first process edge (11) for being closely attached to the first positioning edge (a) of the test piece; A second limiting card (121) is provided on the second process edge (12) for being closely attached to the second positioning edge (b) of the test piece.

2. The strain gauge pasting auxiliary tooling according to claim 1 is characterized in that: One side of the strain gauge pasting position (13) is of open design.

3. The strain gauge pasting auxiliary tooling according to claim 1 is characterized in that: The positioning plate has a first surface that fits the surface of the test piece, and a second surface (10) opposite to the first surface is provided with a pressing auxiliary surface (131) for assisting in pressing the strain gauge.

4. The strain gauge pasting auxiliary tooling according to claim 3 is characterized in that: The distance between the pressing auxiliary surface (131) and the first surface is smaller than the thickness of the strain gauge.

5. The strain gauge pasting auxiliary tooling according to claim 3 is characterized in that: The area of ​​the pressing auxiliary surface (131) is larger than the area of ​​the strain gauge pasting position (13), and the center of the pressing auxiliary surface (131) coincides with the center of the strain gauge pasting position (13).

6. The strain gauge pasting auxiliary tooling according to claim 3 is characterized in that: A positioning auxiliary line (132) for assisting the positioning of the strain gauge is provided on the pressing auxiliary surface (131).

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