Tensile strain testing device for small sample material

Abstract

According to the tensile strain testing device for the small sample material, a displacement load is applied to a stress conduction guide rod, and the load is transmitted to an elastic piece through the stress conduction guide rod and a mechanical sensor, then transmitted to a square guide rod through the elastic piece and finally transmitted to an upper clamp and a sample through the square guide rod; and the double-frequency laser interferometer is used for measuring the displacement of the square guide rod, namely the stretching displacement of the sample. The measuring device provided by the utility model can be suitable for the sample size as small as millimeter magnitude, the measuring precision can reach nanometer magnitude, and the measuring device is simple and convenient to operate and has remarkable practical value.

Description

Technical Field

[0001] The utility model belongs to the technical field related to material stress-strain testing, and in particular relates to a tensile strain testing device for small sample materials. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] After nuclear energy materials are damaged by radiation (such as neutron, electron or ion radiation), creep will occur, that is, the strain of the material increases over time under the condition of keeping the stress unchanged. Therefore, by measuring the stress-strain relationship of the material, the creep behavior of the material under irradiation conditions can be further described and quantified. This measurement is crucial for understanding and predicting the performance of nuclear energy materials in actual use environments. There are currently a variety of devices on the market for measuring material strain, and the material sample sizes they measure are usually on the order of centimeters. However, for small sample materials with sizes on the order of millimeters or sub-millimeters, especially after the introduction of radiation, the internal structure of the material changes, and traditional strain measurement methods face greater challenges. These methods are difficult to accurately capture the tiny displacement changes of the material during the stretching process. Therefore, it is particularly important to develop new technologies and equipment that can accurately measure the strain behavior of small-sized samples under irradiation conditions.

[0004] my country's research on small sample testing technology started late. Currently, only a few institutions such as the China Institute of Atomic Energy, China Special Equipment Testing and Research Institute, and Shanghai Jiao Tong University are conducting research on small sample testing technology. However, the measurement technology for the tensile strain of small sample materials is still imperfect, and there is no mature commercial equipment so far.

[0005] In summary, providing a method that can be used to measure the tiny strain of small sample materials on the millimeter scale and provide accurate data for subsequent irradiation creep analysis of materials is a technical problem that needs to be solved at present. Utility Model Content

[0006] In order to solve the above problems, the utility model proposes a tensile strain testing device for small sample materials. The measuring device can be applicable to sample sizes as small as millimeters, the measurement accuracy can reach nanometers, and it is easy to operate, with significant practical value.

[0007] According to some embodiments, the present invention adopts the following technical solution: a tensile strain testing device for small sample materials, comprising: a support frame, a stress conduction guide rod, a mechanical sensor, an elastic member, a square guide rod, an upper fixture, and a dual-frequency laser interferometer;

[0008] One end of the mechanical sensor is connected to the stress conduction guide rod, and the other end of the mechanical sensor is connected to the elastic member; the elastic member is connected to the square guide rod;

[0009] The upper clamp is arranged in the square guide rod and connected to the square guide rod, and the upper clamp is used to clamp the sample along the stretching direction;

[0010] The dual-frequency laser interferometer is arranged at the bottom of the supporting frame and is used to measure the displacement of the square guide rod.

[0011] In addition, a tensile strain testing device for small sample materials according to an embodiment of the present invention may also have the following additional technical features:

[0012] Preferably, the support frame includes four support rods and a cross rod, the four support rods form a square structure, and the cross rod is horizontally arranged in the square structure.

[0013] Preferably, the stress conduction guide rod is arranged in a sleeve, and the sleeve passes through the upper support rod of the support frame.

[0014] Preferably, a lower clamp is further included, and the lower clamp is used to fix the sample.

[0015] Preferably, the lower clamp is arranged on the cross bar.

[0016] Preferably, the square guide rod is arranged through the cross rod.

[0017] Preferably, the square guide rod includes four guide rods, the four guide rods form a square structure, and the guide rods parallel to each other in the vertical direction are respectively arranged in the sleeves.

[0018] Preferably, the dual-frequency laser interferometer is arranged below the square guide rod.

[0019] Preferably, the dual-frequency laser interferometer adopts LH3000.

[0020] Preferably, the elastic member is a spring.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] This utility model applies a displacement load to a stress-transmitting guide rod. The load is then transmitted by the stress-transmitting guide rod and the force sensor to the elastic member, which then transmits the load to the square guide rod. Finally, the square guide rod transmits the load to the upper fixture and sample. A dual-frequency laser interferometer measures the displacement of the square guide rod, i.e., the sample's tensile displacement. The measurement device provided by this utility model is suitable for samples as small as millimeters, achieves measurement accuracy in the nanometer range, and is easy to operate, possessing significant practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0024] Figure 1 This is a schematic diagram of the overall structure of the tensile strain testing device of the present utility model;

[0025] Figure 2 This is a top view of the support frame in the utility model;

[0026] Figure 3 This is a schematic diagram of the measurable sample size of the tensile strain testing device in the present utility model;

[0027] In the figure, 1. spring, 2. fixture, 3. sample, 4. support frame, 5. square guide rod, 6. sleeve, 7. dual-frequency laser interferometer, 8. stress conduction guide rod, 9. mechanical sensor. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0030] In the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are relational terms determined merely for the convenience of describing the structural relationships of the various parts or elements of the present invention. They do not specifically refer to any part or element in the present invention and cannot be understood as limitations on the present invention. In the present invention, terms such as "fixed connection", "connected", "connected" and the like should be understood in a broad sense, indicating that they can be fixedly connected, integrally connected or detachably connected; they can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meanings of the above terms in the present invention according to specific circumstances, and they cannot be understood as limitations on the present invention.

[0031] Example 1

[0032] like Figure 1-Figure 3As shown, the utility model provides a tensile strain testing device for small sample materials, comprising: a support frame 4, a stress conduction guide rod 8, a mechanical sensor 9, an elastic member, a square guide rod 5, an upper fixture and a dual-frequency laser interferometer 7;

[0033] One end of the mechanical sensor 9 is connected to the stress conduction guide rod 8, and the other end of the mechanical sensor 9 is connected to the elastic member;

[0034] The upper clamp is arranged in the square guide rod 5 and connected to the square guide rod 5. The square guide rod 5 is connected to the elastic member. The upper clamp is used to clamp the sample 3 along the stretching direction.

[0035] The dual-frequency laser interferometer 7 is arranged at the bottom of the supporting frame 4 and is used to measure the displacement of the square guide rod 5 .

[0036] In this embodiment, the elastic member is specifically a spring 1 .

[0037] In this embodiment, by applying a displacement load to the stress conduction guide rod 8, the load is transmitted by the stress conduction guide rod 8 and the mechanical sensor 9 to the spring 1, and then transmitted by the spring 1 to the square guide rod 5, and finally transmitted by the square guide rod 5 to the upper fixture and the sample 3; the mechanical sensor 9 can directly measure the stress of the applied displacement load, and the dual-frequency laser interferometer 7 can directly measure the displacement of the square guide rod 5, that is, the deformation length of the sample 3 when stretched, and the sample strain is calculated based on the sample length and the deformation length of the sample when stretched.

[0038] Specifically, the support frame 4 includes four support rods and a cross rod. The four support rods form a square structure. The cross rod is horizontally arranged in the square structure and has a certain distance between the upper support rod and the lower support rod parallel to each other in the horizontal direction.

[0039] In this embodiment, the stress conduction guide rod 8 is arranged in the sleeve 6 , the sleeve 6 is arranged to pass through the upper cross bar of the support frame 4 , and the sleeve 6 is connected to the upper cross bar of the support frame 4 .

[0040] Optionally, the inner diameter of the sleeve 6 is 2 cm, and the diameter of the stress conduction rod 8 is 1.5 cm.

[0041] Optionally, the sleeve 6 is in the shape of a circular tube.

[0042] In this embodiment, the movement of the stress conduction guide rod 8 is controlled by the stress F. A mechanical sensor 9 is connected below the stress conduction guide rod 8. The mechanical sensor 9 is connected to the spring 1. The mechanical sensor 9 can directly output the magnitude of the loading stress.

[0043] In this embodiment, the load is transmitted through the spring 1 to prevent sudden changes in the load from causing damage to the sample 3.

[0044] In this embodiment, the square guide rods 5 include four guide rods that form a square structure, and the guide rod columns are cylindrical. Two vertically parallel guide rods in the square guide rods 5 are respectively mounted in sleeves 6, which extend through the crossbars of the support frame 4 and are connected to the crossbars of the support frame 4.

[0045] In this embodiment, two sleeves 6 are used to fix the square guide rod 5 to prevent rotation and instability during the stretching process of the sample 3.

[0046] Optionally, the diameter of the square guide rod 5 is 1.5 cm.

[0047] In this embodiment, the stress conduction guide rod 8 and the square guide rod 5 conduct force loading during the stretching process, applying a load to the sample 3.

[0048] In this embodiment, the clamp 2 includes an upper clamp and a lower clamp, both of which are arranged in the square guide rod 5. The upper clamp is connected to the upper cross bar of the square guide rod 5, and the upper clamp can move up and down. The upper clamp is used to clamp the sample 3 along the stretching direction; the lower clamp is arranged on the cross bar in the support frame 4, and the lower clamp is used to clamp the sample 3 and fix the sample 3.

[0049] Optionally, the size of the clamp 2 is 2.5 cm.

[0050] Optionally, sample 3 is a long thin sheet that is wide at both ends and narrow in the middle, with a thickness of 0.5 mm, a length of 28 mm, a width of 8 mm at both ends, and a width of 2 mm in the middle.

[0051] Optionally, the sample 3 includes two 8×13 mm rectangles at the top and bottom and a 12×2 mm tensile portion in the middle, which facilitates the fixture 2 to clamp the sample 3 firmly.

[0052] In this embodiment, the dual-frequency laser interferometer 7 is located below the square guide rod 5. Specifically, the dual-frequency laser interferometer 7 is set at the inner bottom of the support frame 4. The dual-frequency laser interferometer 7 consists of three parts: a dual-frequency laser head, an environment measurement and wavelength supplementation unit, and a linear displacement measurement unit.

[0053] Optionally, the resolution of the dual-frequency laser head is 1 nm, and the dual-frequency laser interferometer model is LH3000.

[0054] The measurement principle of the tensile strain testing device for small sample materials provided in this embodiment is: by applying a displacement load to the stress conduction guide rod 8, the load is transmitted to the spring 1 by the stress conduction guide rod 8 and the mechanical sensor 9, and then transmitted to the square guide rod 5 by the spring 1, and finally transmitted to the clamp 2 and the sample 3 by the square guide rod 5. At this time, the clamp 2 clamps the sample 3, and the support frame 4 and the sleeve 6 maintain the overall stable operation of the device. The mechanical sensor 9 can directly measure the stress size σ of the applied displacement load, and the dual-frequency laser interferometer 7 can directly measure the displacement of the square guide rod 5, that is, the deformation length x of the sample 3 when stretched. The sample strain can be calculated based on the sample length and the deformation length x of the sample when stretched. Then the stress-strain curve can be drawn.

[0055] When performing a tensile displacement test on a small sample material, the tensile strain testing device provided in this embodiment first fixes the test sample with a clamp, then applies stress to drive the stress conduction guide rod and the square guide rod to move to achieve stretching of the sample. The stress value distribution of the entire process is measured by a mechanical sensor, and the displacement of the lower end of the square guide rod is measured using a dual-frequency laser interferometer to obtain the strain value of the sample during the stretching process, and then the stress-strain relationship of the sample is calculated.

[0056] The tensile strain testing device for small sample materials proposed in this embodiment can be used to measure minute strains on samples as small as millimeters, with strain accuracy down to the nanometer level, providing accurate data for irradiation creep analysis of materials. The instrument features easy operation, a simple testing platform, and high measurement accuracy.

[0057] Although the above description of the specific implementation methods of the present invention is combined with the accompanying drawings, it does not limit the scope of protection of the present invention. Technical personnel in the relevant field should understand that on the basis of the technical solution of the present invention, various modifications or deformations that can be made by technical personnel in this field without creative work are still within the scope of protection of the present invention.

Claims

1. A tensile strain testing device for small sample materials, characterized in that: include: Support frame, stress conduction guide rod, mechanical sensor, elastic member, square guide rod, upper fixture and dual-frequency laser interferometer; One end of the mechanical sensor is connected to the stress conduction guide rod, and the other end of the mechanical sensor is connected to the elastic member; the elastic member is connected to the square guide rod; The upper clamp is arranged in the square guide rod and connected to the square guide rod, and the upper clamp is used to clamp the sample along the stretching direction; The dual-frequency laser interferometer is arranged at the bottom of the supporting frame and is used to measure the displacement of the square guide rod.

2. A tensile strain testing device for small sample materials according to claim 1, characterized in that: The support frame includes four support rods and a cross rod. The four support rods form a square structure, and the cross rod is horizontally arranged in the square structure.

3. The tensile strain testing device for small sample materials according to claim 1, characterized in that: The stress conduction guide rod is arranged in a sleeve, and the sleeve passes through the upper support rod of the support frame.

4. A tensile strain testing device for small sample materials according to claim 2, characterized in that: The tensile strain testing device further includes a lower clamp, which is used to fix the sample.

5. The tensile strain testing device for small sample materials according to claim 4, characterized in that: The lower clamp is arranged on the cross bar.

6. The tensile strain testing device for small sample materials according to claim 2, characterized in that: The square guide rod is arranged to pass through the cross rod.

7. A tensile strain testing device for small sample materials according to claim 1 or 6, characterized in that: The square guide rods include four guide rods, which form a square structure. The guide rods parallel to each other in the vertical direction are respectively arranged in the sleeves.

8. The tensile strain testing device for small sample materials according to claim 1, characterized in that: The dual-frequency laser interferometer is arranged below the square guide rod.

9. The tensile strain testing device for small sample materials according to claim 1, characterized in that: The dual-frequency laser interferometer adopts LH3000.

10. The tensile strain testing device for small sample materials according to claim 1, characterized in that: The elastic member is a spring.

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