Stress detection device

Abstract

To provide a stress detection device that can detect stress with high sensitivity. [Solution] The system comprises an installation portion provided in a structure and a stress sensor installed in the installation portion, wherein the installation portion is such that, in a cross-section taken by a plane perpendicular to the plane on which the stress applied to the installation portion is measured, the cross-sectional area of ​​the structure including the installation portion is smaller than the cross-sectional area of ​​the structure excluding the installation portion. The installation portion is a suspension member suspended in an opening formed in the structure, and the stress sensor is installed on the suspension member.

Description

Technical Field

[0001] The present disclosure relates to a stress detection device.

Background Art

[0002] Conventionally, for the purpose of measuring stress distribution, it is known to attach and fix a strain gauge to the surface of a measurement target (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0004] However, when the installation portion for the strain gauge that is the measurement target is a site with a large stress gradient, the measured value may be affected by misalignment of the installation position. In addition, when the installation portion for the strain gauge that is the measurement target is a site with a small stress gradient, such as a thin-walled portion, noise may be mixed into the measured value due to the influence of secondary bending deformation or the like.

[0005] Accordingly, an object of the present disclosure is to provide a stress detection device capable of detecting stress with high sensitivity.

Means for Solving the Problems

[0006] A stress detection device of the present disclosure includes an installation portion provided in a structure, and a stress sensor installed in the installation portion, and in a cross-section cut along a plane orthogonal to the surface for measuring the stress applied to the installation portion, the cross-sectional area of the structure including the installation portion is smaller than the cross-sectional area of the structure not including the installation portion.

[0007] Furthermore, other stress detection devices of this disclosure include a stress detection member installed on a structure and an evaluation chart for evaluating stress based on the state of the stress detection member, wherein the stress detection member has a cross-sectional area in which it is cut by a plane perpendicular to the plane on which the stress applied to the stress detection member is measured, such that the cross-sectional area of ​​the structure including the stress detection member is smaller than the cross-sectional area of ​​the structure not including the stress detection member, and includes a fracture site that breaks when stress is applied. [Effects of the Invention]

[0008] According to this disclosure, stress can be detected with high sensitivity. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram of a stress detection device according to the first embodiment. [Figure 2] Figure 2 is a schematic cross-sectional view of a stress detection device according to the first embodiment. [Figure 3] Figure 3 is a plan view showing an example of a suspension member. [Figure 4] Figure 4 is a plan view showing an example of a suspension member. [Figure 5] Figure 5 is a schematic diagram of a stress detection device according to the second embodiment. [Figure 6] Figure 6 is a schematic diagram of an evaluation chart used to assess stress. [Modes for carrying out the invention]

[0010] Embodiments relating to this disclosure will be described in detail below with reference to the drawings. However, these embodiments do not limit this disclosure. Furthermore, some components in the embodiments described below are substituted or substantially identical to those easily substituted by those skilled in the art. Moreover, the components described below can be combined as appropriate, and if there are multiple embodiments, each embodiment can be combined.

[0011] [First Embodiment] The stress detection device 10 according to the first embodiment detects the stress applied to the structure 5. Furthermore, the stress detection device 10 may also detect and monitor the load applied to the structure 5, the strain applied to the structure 5, damage to the structure 5, etc., based on the detected stress.

[0012] Figure 1 is a schematic diagram of a stress detection device according to the first embodiment. Figure 2 is a schematic cross-sectional view of the stress detection device according to the first embodiment. Figures 3 and 4 are plan views showing an example of a suspension member.

[0013] As shown in Figure 1, the structure 5 on which the stress detection device 10 is installed is, for example, a longitudinally extending member with an H-shaped cross-section. Note that the structure 5 shown in Figure 1 is just an example and is not particularly limited. The structure 5 shown in Figure 1 has a web 5a in which an opening 6 is formed, and a pair of flanges 5b provided on both sides of the web 5a in the width direction. The opening 6 is, for example, an existing weight-reducing hole for reducing the weight of the structure 5.

[0014] (Stress detection device) The stress detection device 10 is installed in an opening 6 formed in the structure 5. The stress detection device 10 comprises an installation part and a stress sensor 12. Examples of the stress detection device 10 include the stress detection device 10a shown in Figure 3 and the stress detection device 10b shown in Figure 4. The stress detection device 10a in Figure 3 and the stress detection device 10b in Figure 4 differ in the shape of their installation parts, resulting in different types of stress being detected.

[0015] The stress detection device 10a in Figure 3 is designed to handle stresses such as tensile stress applied in the in-plane direction of the web 5a.

[0016] The installation portion of the stress detection device 10a in Fig. 3 is a suspension member 11 suspended in an opening 6 formed in the structure 5. The suspension member 11 is a disk-shaped member in which a plurality of rod portions 11a extending radially from the center of the opening 6 and an annular portion 11b provided along the peripheral edge of the opening 6 are integrated. The annular portion 11b is fixed to the structure 5, and transmits the stress applied to the structure 5 to the rod portions 11a.

[0017] Here, the cross section of the structure 5 will be described with reference to Fig. 1 and Fig. 2. The structure 5 on which the suspension member 11 is installed has a cross section taken along a plane orthogonal to the plane for measuring the stress applied to the suspension member 11 (for example, the plane including the vertical direction and the front-rear direction in Fig. 2), which is as shown in Fig. 2. The diagram on the left side of Fig. 2 is cross section A of the structure 5 that does not include the suspension member 11. The diagram on the right side of Fig. 2 is cross section B of the structure 5 that includes the suspension member 11. As shown in Fig. 2, the cross-sectional area of cross section B of the structure 5 including the suspension member 11 is smaller than the cross-sectional area of cross section A of the structure 5 not including the suspension member 11. For this reason, the stress applied to the structure 5 is applied to the rod portions 11a of the suspension member 11 having a small cross-sectional area, so that the rod portions 11a can be appropriately displaced.

[0018] The stress sensor 12 is, for example, a strain gauge. The stress sensor 12 is disposed on each of the plurality of rod portions 11a. The plurality of stress sensors 12 are disposed at equal angles with different phases within the plane of the web 5a. Therefore, the plurality of stress sensors 12 can detect the vector component and magnitude of the stress applied in the in-plane direction of the web 5a.

[0019] The stress detection device 10b in Fig. 4 is a device designed on the assumption that bending stress is applied to the web 5a.

[0020] The installation portion of the stress detection device 10b in Figure 4 is a suspension member 21 that is suspended in an opening 6 formed in the structure 5. The suspension member 21 is a disc-shaped member in which two diagonal portions 21a arranged on diagonals with the center of the opening 6 as the intersection, four side portions 21b arranged on the four sides of a square whose diagonals are the two diagonal portions 21a, and an annular portion 21c provided along the peripheral edge of the opening 6 are integrated. The annular portion 21c is fixed to the structure 5, and transmits the stress applied to the structure 5 to the diagonal portions 21a and the side portions 21b.

[0021] In the stress detection device 10b of Figure 4, similar to the stress detection device 10a of Figure 3, the cross-sectional area of the cross section B of the structure 5 including the suspension member 21 is smaller than the cross-sectional area of the cross section A of the structure 5 not including the suspension member 21. For this reason, the stress applied to the structure 5 is applied to the diagonal portions 21a and the side portions 21b of the suspension member 21 having a small cross-sectional area, so that the diagonal portions 21a and the side portions 21b can be appropriately displaced.

[0022] The stress sensor 12 is, for example, a strain gauge. The stress sensor 12 is disposed on each of the two diagonal portions 21a and the four side portions 21b. The plurality of stress sensors 12 are arranged in a square frame shape within the plane of the web 5a, and are also arranged on the diagonals inside the frame. Therefore, the plurality of stress sensors 12 can detect the vector component and magnitude of the bending stress applied by the bending of the web 5a.

[0023] Note that, in the present embodiment, the suspension members 11 and 21 are used as the installation portion, but a recess that is recessed concavely from the surface of the structure 5 may be used. That is, an existing recess formed in the structure 5 may be utilized.

[0024] [Second Embodiment] Next, a second embodiment will be described with reference to Figures 5 and 6. Figure 5 is a schematic diagram of a stress detection device according to the second embodiment. Figure 6 is a schematic diagram of an evaluation chart for evaluating stress. In the second embodiment, in order to avoid redundant descriptions, only the parts that differ from the first embodiment will be described, and parts that have the same configuration as the first embodiment will be denoted by the same reference numerals.

[0025] (Stress detection device) The stress detection device 30 of the second embodiment is installed in an opening 6 formed in the structure 5. The stress detection device 10 comprises a stress detection member 31 and an evaluation chart D. The stress detection device 30 is a device that detects stress when stress is applied to the web 5a and the stress detection member 31 breaks.

[0026] The stress sensing member 31 is installed in an opening 6 formed in the structure 5. The stress sensing member 31 is a disc-shaped member in which a fracture portion 31a provided in the opening 6 and an annular portion 31b provided along the periphery of the opening 6 are integrated. The fracture portion 31a is a part that fractures when a stress exceeding a predetermined threshold stress is applied, and is, for example, a metal mesh. The annular portion 31b is fixed to the structure 5 and transmits the stress applied to the structure 5 to the fracture portion 31a.

[0027] In the structure 5 on which the stress sensing member 31 is installed, the cross-sectional area of ​​the structure 5 including the stress sensing member 31 is smaller than the cross-sectional area of ​​the structure 5 excluding the stress sensing member 31, when the structure 5 is cut by a plane perpendicular to the plane on which the stress applied to the stress sensing member 31 is measured. When stress is applied to the structure 5, it is applied to the fracture portion 31a of the stress sensing member 31, causing the fracture portion 31a to break.

[0028] Evaluation chart D evaluates stress based on the fracture state of the stress sensing member 31. Evaluation chart D may be data or a data sheet such as a specification, and is not particularly limited. Evaluation chart D associates the fracture state of the fracture site 31a with the vector components and magnitude of the stress applied to the web 5a. Therefore, by comparing the fracture state of the fracture site 31a with evaluation chart D, it is possible to obtain the vector components and magnitude of the stress applied to the web 5a.

[0029] As described above, the stress detection devices 10 and 30 described in the first and second embodiments can be understood, for example, as follows.

[0030] The stress detection device 10 according to the first embodiment comprises an installation part provided on a structure and a stress sensor 12 installed on the installation part, wherein, in a cross-section of the installation part cut by a plane perpendicular to the plane on which the stress applied to the installation part is measured, the cross-sectional area of ​​the structure 5 including the installation part is smaller than the cross-sectional area of ​​the structure 5 excluding the installation part.

[0031] With this configuration, the cross-sectional area of ​​the structure 5, including the installation part, can be reduced, making the installation part more easily deformed by the stress applied to the structure 5, and allowing the stress sensor 12 to detect the stress with high sensitivity.

[0032] In a second embodiment, in the stress detection device 10 according to the first embodiment, the installation portion is a recess that is recessed from the surface of the structure 5.

[0033] With this configuration, the stress sensor 12 can be placed in a recess provided on the surface of the structure 5, making it possible to utilize existing recesses.

[0034] In a third embodiment, in the stress detection device 10 according to the first embodiment, the installation portion is a suspension member 11, 21 suspended from an opening 6 formed in the structure, and the stress sensor 12 is installed on the suspension member 11, 21.

[0035] With this configuration, since the suspension members 11 and 21 can be placed in the opening 6 formed in the structure 5, it becomes possible to utilize the existing opening 6.

[0036] In a fourth embodiment, in the stress detection device 10 according to the third embodiment, the suspension member 11 includes a plurality of rod portions 11a extending radially from the center of the opening 6, and the stress sensor 12 is installed on each of the rod portions 11a.

[0037] This configuration makes it possible to detect the vector components and magnitude of stresses such as tensile stress applied to the suspension member 11.

[0038] In a fifth embodiment, in the stress detection device 10 according to the third embodiment, the suspension member 21 includes two diagonal portions 21a arranged diagonally with the center of the opening 6 as the intersection point, and four side portions 21b arranged on the four sides of a rectangle formed by the two diagonal portions 21a as diagonals, and the stress sensor 12 is installed in each of the two diagonal portions 21a and the four side portions 21b.

[0039] This configuration makes it possible to detect the vector components and magnitude of stresses such as bending stress applied to the suspension member 11.

[0040] A stress detection device 30 according to a sixth embodiment comprises a stress detection member 31 installed on a structure and an evaluation chart D for evaluating stress based on the state of the stress detection member 31, wherein the stress detection member 31 has a cross-sectional area in which it is cut by a plane perpendicular to the plane on which the stress applied to the stress detection member 31 is measured, and the cross-sectional area of ​​the structure 5 including the stress detection member 31 is smaller than the cross-sectional area of ​​the structure 5 not including the stress detection member 31, and includes a fracture portion 31a that fractures when stress is applied.

[0041] This configuration allows for a smaller cross-sectional area of ​​the structure 5 including the stress sensing member 31, making it easier for the stress applied to the structure 5 to cause the fracture portion 31a of the stress sensing member 31 to break. Furthermore, stress can be detected with high sensitivity by comparing the fracture state of the stress sensing member 31 with the evaluation chart D. [Explanation of symbols]

[0042] 10, 30 Stress detection device 5 Structure 6 aperture 11 Suspension members 11a Rod part 12. Stress Sensor 21 Suspension member 21a Diagonal section 21b Side part 31 Stress sensing member 31a Fracture site D Evaluation Chart

Claims

1. Installation part provided in the structure, The installation part includes a stress sensor installed in the aforementioned installation section, The stress detection device wherein the mounting portion is such that, in a cross-section taken by a plane perpendicular to the plane on which the stress applied to the mounting portion is measured, the cross-sectional area of ​​the structure including the mounting portion is smaller than the cross-sectional area of ​​the structure excluding the mounting portion.

2. The stress detection device according to claim 1, wherein the installation portion is a recess that is recessed from the surface of the structure.

3. The aforementioned installation portion is a suspension member suspended in an opening formed in the structure, The stress detection device according to claim 1, wherein the stress sensor is installed on the suspension member.

4. The suspension member includes a plurality of rod portions extending radially from the center of the opening, The stress detection device according to claim 3, wherein the stress sensor is installed on each of the rod portions.

5. The suspension member includes two diagonal portions arranged diagonally with the center of the opening as the intersection point, and four side portions arranged on the four sides of a rectangle formed by the two diagonal portions as diagonals. The stress detection device according to claim 3, wherein the stress sensors are installed in each of the two diagonal portions and the four side portions.

6. A stress sensing member installed in the structure, The system includes an evaluation chart for evaluating stress based on the state of the stress sensing member, The stress detection device includes a stress detection member wherein, when the stress is measured by a plane perpendicular to the plane on which the stress applied to the stress detection member is measured, the cross-sectional area of ​​the structure including the stress detection member is smaller than the cross-sectional area of ​​the structure not including the stress detection member, and the device includes a fracture site that breaks when stress is applied.

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