Insulator mechanical test tool, test platform and method for nuclear fusion

Abstract

The invention relates to the technical field of testing devices, and discloses a mechanical testing tool, platform and method for an insulator for nuclear fusion, and the tool comprises a center rod which is disposed at a detection end of a testing machine, and is connected with the insulator at the other end; the insulator positioning frame or the center rod is connected with the force application end of the testing machine; the connecting structure is a tensile compression performance test connecting structure or a bending performance test connecting structure or a torsion performance test connecting structure, and the tensile compression performance test connecting structure, the bending performance test connecting structure and the torsion performance test connecting structure can be replaced with one another. After one-time performance testing is completed, the tool subjected to performance testing can be dismantled and replaced with other performance testing tools, and therefore stretching, compression, bending and torsion performance testing can be conducted on the insulator, the performance of the low-temperature insulator under various loads can be evaluated more comprehensively, and comprehensive detection of the insulator is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of testing devices, and in particular to a mechanical testing tool, a testing platform and a method for an insulator used in nuclear fusion. Background Art

[0002] Insulators are key components in nuclear fusion magnet systems. Insulators serve as insulating channels for liquid nitrogen and liquid helium in the longitudinal field superconducting magnets, poloidal field superconducting magnets, internal and external nitrogen screens, and current leads of the main engine of nuclear fusion devices (such as ITER). They form a cooling circuit through pipelines and cold mass components, and also serve as insulation to the ground. The main performance indicators of cryogenic insulators include mechanical strength, electrical properties, low temperature resistance, airtightness, impact resistance, etc. In order to ensure the safe operation of the nuclear fusion magnet system, all insulators need to undergo multiple rounds of performance verification tests, including hot and cold cycle tests, electrical performance tests, mechanical fatigue tests, and helium airtightness tests.

[0003] The existing insulator mechanical properties testing machine only has the performance test of tension and compression at room temperature, and cannot comprehensively evaluate the performance of low-temperature insulators under various loads under low-temperature conditions. Summary of the invention

[0004] In view of this, the present invention provides a mechanical testing tool, a testing platform and a method for insulators for nuclear fusion, so as to solve the problem that the existing insulator mechanical property testing machine cannot comprehensively evaluate the performance of low-temperature insulators under various loads.

[0005] In a first aspect, the present invention provides a mechanical testing tool for an insulator for nuclear fusion, comprising:

[0006] A center rod, one end of which is set on the detection end of the testing machine and the other end is connected to the insulator;

[0007] An insulator positioning frame, comprising an insulator positioning frame first end and an insulator positioning frame second end, wherein the center rod movably passes through the insulator positioning frame first end; the insulator positioning frame or the center rod is connected to a force-applying end of a testing machine so as to apply a load to the insulator through the force-applying end of the testing machine;

[0008] A connection structure, wherein the connection structure is a tensile-compression performance test connection structure or a bending performance test connection structure or a torsion performance test connection structure, and the tensile-compression performance test connection structure, the bending performance test connection structure and the torsion performance test connection structure can be replaced with each other; when the connection structure is a tensile-compression performance test connection structure, one end of the insulator is coaxially connected to the center rod, and the other end of the insulator is connected to the second end of the insulator positioning frame; when the connection structure is a bending performance test connection structure, one end of the insulator is perpendicularly connected to the center rod, and the other end of the insulator is connected to the insulator positioning frame through the bending performance test connection structure; when the connection structure is a torsion performance test connection structure, one end of the insulator is perpendicularly connected to the center rod and is not coplanar with the center rod, and the other end of the insulator is connected to the insulator positioning frame through the bending performance test connection structure.

[0009] The above-mentioned mechanical testing tool for insulators for nuclear fusion uses a connecting structure to arrange insulators in different positions. The tensile and compression performance test connecting structure, the bending performance test connecting structure and the torsion performance test connecting structure can be replaced with each other. After completing a performance test, the tooling that has been used for performance testing can be removed and replaced with other performance testing tooling, thereby ensuring that the mechanical testing tool for insulators for nuclear fusion can perform tensile, compression, bending and torsion performance tests on insulators respectively, and can more comprehensively evaluate the performance of low-temperature insulators under various loads, thereby achieving comprehensive testing of insulators.

[0010] In an optional implementation, a first insulator flange is provided at one end of the insulator, and a second insulator flange is provided at the other end of the insulator; and a center rod connecting flange is provided on the center rod.

[0011] The first insulator flange and the second insulator flange can be easily tested for mechanical properties.

[0012] In an optional embodiment, the connection structure is a tensile and compressive performance test connection structure, the first flange of the insulator is connected to the center rod connecting flange, and the second flange of the insulator is connected to the insulator positioning frame, so that the insulator and the center rod are coaxially connected. When the force-applying end of the testing machine applies force to the insulator positioning frame or the center rod, the insulator can be driven to stretch or compress, thereby realizing the tensile or compressive performance test of the insulator.

[0013] In an optional embodiment, the connection structure is a bending performance test connection structure, which includes a fixed flange and a fixed rod, wherein the fixed flange is connected to the first end of the insulator positioning frame and / or the second end of the insulator positioning frame through the fixed rod, and the second flange of the insulator is connected to the fixed flange; the center rod is connected to the first flange of the insulator through the first flange connecting rod, and the center line extension line of the center rod intersects perpendicularly with the center line extension line of the insulator, and then when the force-applying end of the testing machine applies force to the insulator positioning frame or the center rod, the load can be applied to the insulator in a direction perpendicular to the axis of the insulator, so that the insulator can bend, thereby realizing the bending performance test of the insulator.

[0014] In an optional embodiment, the connection structure is a torsional performance test connection structure, which includes a fixed flange and a fixed rod, wherein the fixed flange is connected to the first end of the insulator positioning frame and / or the second end of the insulator positioning frame through the fixed rod, and the second insulator flange is connected to the fixed flange; the center rod is connected to the first insulator flange through the first flange connecting rod, and the first insulator flange is connected to the second end of the insulator positioning frame through the second flange connecting rod, and the first flange connecting rod and the second flange connecting rod are located on both sides of the insulator, so that when the force-applying end of the testing machine applies force to the insulator positioning frame or the center rod, the load can be applied to the first flange of the insulator in a direction perpendicular to the axis of the insulator, so that the insulator can be twisted, thereby realizing the torsional performance test of the insulator.

[0015] In an optional embodiment, the outer sliding sleeve of the central rod is provided with a neck tube, one end of the neck tube is connected to the insulator positioning frame, and the other end of the neck tube is connected to a connecting flange;

[0016] The connecting flange is connected to the force-applying end of the testing machine, and the center rod is connected to the fixed end of the testing machine; or the connecting flange is connected to the fixed end of the testing machine, and the center rod is connected to the force-applying end of the testing machine.

[0017] In a second aspect, the present invention further provides a mechanical testing platform for insulators for nuclear fusion, comprising:

[0018] Testing machine;

[0019] The insulator mechanical testing tool for nuclear fusion is arranged on a testing machine;

[0020] The low temperature box is installed on the testing machine and is used to provide a low temperature environment for the insulator.

[0021] The above-mentioned mechanical testing platform for insulators for nuclear fusion can not only test the mechanical properties of insulators at room temperature, but also test the mechanical properties of insulators at low temperature. When testing the mechanical properties of insulators at low temperature, the insulators can be arranged in a low temperature box, and the mechanical properties of the insulators can be tested in the low temperature box. The present invention solves the problem that the mechanical properties of low-temperature insulators cannot be tested in a low-temperature environment. Through this platform, various loads (tension, compression, bending, torsion, fatigue) of low-temperature insulators at room temperature and low temperature can be tested, and at the same time, their low-temperature resistance and impact resistance can be tested, which provides support for testing the performance of low-temperature insulators at different temperatures and provides guarantee for the safe and reliable operation of nuclear fusion devices.

[0022] In an optional embodiment, the testing machine is a static electronic universal testing machine; the testing machine comprises:

[0023] The support frame comprises a frame body, a fixed beam and a movable beam, wherein the movable beam is slidably arranged on the frame body, the movable beam is a force-applying end of the static electronic universal testing machine, and the movable beam is connected to a connecting flange;

[0024] A base is arranged at the bottom of the support frame, and the low temperature box is arranged on the base;

[0025] The first force sensor is arranged at the bottom of the fixed beam of the testing machine. The first force sensor is the detection end of the static electronic universal testing machine. The center rod is connected to the first force sensor.

[0026] The above-mentioned static electronic universal testing machine cancels the hydraulic device, and uses the movable beam to drive the neck tube to move to achieve the force on the insulator, which greatly reduces the size of the tooling, so that the insulator positioning frame and the insulator can be accommodated in the liquid nitrogen test dewar. In addition, the present invention uses the insulator positioning frame to position the insulator, and according to the arrangement of the insulator and the insulator positioning frame, the liquid nitrogen dewar of different shapes is replaced, so that the insulator and the insulator positioning frame can be accommodated in the liquid nitrogen dewar.

[0027] In an optional embodiment, the testing machine is an electro-hydraulic servo dynamic fatigue testing machine, and the testing machine comprises:

[0028] frame;

[0029] An actuator, which is arranged on the frame and connected to the center rod, and is the force-applying end of the testing machine;

[0030] A fixing frame, which is arranged on the frame, and is a fixed end of the testing machine, and is connected to a connecting flange;

[0031] The second force sensor is arranged at the connection between the central rod and the actuator.

[0032] In the above-mentioned electro-hydraulic servo dynamic fatigue testing machine, the actuator can apply a load to the central rod, and the loading of tensile, compressive, torsion and bending fatigue loads is achieved through the reciprocating motion of the actuator.

[0033] In an optional embodiment, the cryogenic box is a liquid nitrogen test dewar, and the liquid nitrogen test dewar comprises an outer cylinder and an inner cylinder, and a hollow interlayer is formed between the outer cylinder and the inner cylinder;

[0034] The hollow interlayer is evacuated and / or provided with a high vacuum multilayer insulation material and / or activated carbon; or, the hollow interlayer is provided with a foaming material and / or a reinforcing rib, which solves the problem that when a conventional liquid nitrogen Dewar is evacuated, the rectangular liquid nitrogen Dewar is deformed and cannot be used, and the foaming material has a good insulation effect.

[0035] In an optional embodiment, the liquid nitrogen test dewar is supplied with liquid nitrogen by a mobile liquid nitrogen dewar, and the mobile liquid nitrogen dewar is arranged beside the support frame, so that the liquid nitrogen can be replenished conveniently and quickly.

[0036] And / or, the liquid nitrogen test dewar can be replaced according to the type of performance test.

[0037] In a third aspect, the present invention further provides a method for mechanical testing of insulators for nuclear fusion, the method being performed based on the mechanical testing platform for insulators for nuclear fusion, and comprising the following steps:

[0038] The insulator is installed on the insulator positioning frame through the tensile and compressive performance test connection structure, so that the insulator is coaxially connected with the center rod, and the load is applied to the insulator through the force-applying end of the testing machine, and the tensile and compressive fatigue tests at room temperature and low temperature are carried out in turn;

[0039] And / or, the insulator is installed on the insulator positioning frame through the bending performance test connection structure, so that the insulator is vertically intersected with the center rod, and a load is applied to the insulator through the force application end of the testing machine, and the bending fatigue test at room temperature and low temperature is carried out in sequence;

[0040] And / or, the insulator is mounted on the insulator positioning frame through the torsion performance test connection structure, the insulator is vertically connected to the center rod and is not coplanar with the center rod, a load is applied to the insulator through the force application end of the testing machine, and torsional fatigue tests at room temperature and low temperature are performed in sequence;

[0041] And / or, the mechanical testing fixture of the insulator for nuclear fusion is installed on the electro-hydraulic servo dynamic fatigue testing machine, and the dynamic fatigue tests of tension, compression, torsion and bending are carried out in sequence.

[0042] In an optional embodiment, when conducting low-temperature tensile and compression fatigue tests and / or bending fatigue tests and / or torsional fatigue tests and / or dynamic fatigue tests, the insulator is immersed in liquid nitrogen to cool the insulator to 77K; wherein, a method for determining that the insulator has been cooled to 77K is as follows: the insulator is completely immersed in liquid nitrogen and the liquid nitrogen does not boil violently; or, the temperature of the insulator is monitored by a thermometer installed near the insulator.

[0043] The present invention can be applied to static tensile, compression, bending, and torsion mechanical performance tests at room temperature and 77K for low-temperature insulators for nuclear fusion, as well as dynamic tensile, compression, bending, and torsion fatigue performance tests, service life assessment, and hot and cold cycle tests. It can also be applied to low-temperature static and dynamic mechanical testing, mechanical fatigue testing, low-temperature resistance testing, and hot and cold shock resistance testing of other low-temperature structural components. Its tooling installation and replacement are simple, convenient, and fast, and it matches the static electronic universal testing machine and the electro-hydraulic servo dynamic fatigue testing machine, and can comprehensively evaluate the mechanical properties, low-temperature resistance, and hot and cold shock resistance of low-temperature insulators. It provides methodological guidance for obtaining effective and reliable characterization of low-temperature insulators, meets my country's demand for mechanical performance data of low-temperature materials such as low-temperature insulators, provides guarantees for the safe and reliable operation of nuclear fusion devices, and ensures the information security of my country's core materials in the service of aerospace military projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 A schematic diagram of the structure of a mechanical testing tool for a nuclear fusion insulator provided by the present invention when conducting tensile and compressive performance tests;

[0046] Figure 2 A cross-sectional view of a mechanical testing tool for a nuclear fusion insulator provided by the present invention when conducting a tensile and compressive performance test;

[0047] Figure 3 A schematic diagram of a portion of the structure of a mechanical testing tool for a nuclear fusion insulator provided by the present invention when conducting a bending performance test;

[0048] Figure 4 A cross-sectional view of a mechanical testing tool for a nuclear fusion insulator provided by the present invention when conducting a bending performance test;

[0049] Figure 5A schematic diagram of a portion of the structure of a mechanical testing tool for a nuclear fusion insulator provided by the present invention when conducting a torsional performance test;

[0050] Figure 6 A cross-sectional view of a mechanical testing tool for a nuclear fusion insulator provided by the present invention when conducting a torsional performance test;

[0051] Figure 7 A schematic diagram of the structure of a nuclear fusion insulator mechanical testing platform provided by the present invention when conducting tensile and compressive performance tests;

[0052] Figure 8 A schematic structural diagram of a nuclear fusion insulator mechanical testing platform provided by the present invention when conducting a bending performance test;

[0053] Fig. 9 For the present invention Figure 8 Schematic diagram of the structure when removing the liquid nitrogen test dewar;

[0054] Fig.10 A schematic diagram of the structure of a nuclear fusion insulator mechanical testing platform provided by the present invention when conducting a torsional performance test;

[0055] Fig.11 For the present invention Fig.10 Schematic diagram of the structure when removing the liquid nitrogen test dewar;

[0056] Fig.12 The present invention is a schematic structural diagram of a nuclear fusion insulator mechanical testing platform during dynamic fatigue testing.

[0057] Description of reference numerals:

[0058] 100. static electronic universal testing machine, 101. support frame, 1001. fixed beam, 1002. movable beam, 102. base, 103. first force sensor;

[0059] 200. Low temperature box;

[0060] 300. electro-hydraulic servo dynamic fatigue testing machine, 301. frame, 302. actuator, 303. second force sensor, 304. fixing frame;

[0061] 400, center rod;

[0062] 500, insulator positioning frame, 501, first flange, 502, second flange, 503, support rod;

[0063] 600, neck pipe, 601, connecting flange;

[0064] 700, connection structure, 701, center rod connecting flange, 702, insulator first flange, 703, insulator second flange, 704, fixing rod, 705, fixing flange, 706, center connecting rod, 707, first flange connecting rod, 708, second flange connecting rod;

[0065] 800, insulator;

[0066] 900. Mobile liquid nitrogen dewar. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0068] Insulators are key components in nuclear fusion magnet systems. Insulators serve as insulating channels for liquid nitrogen and liquid helium in the longitudinal field superconducting magnets, poloidal field superconducting magnets, internal and external nitrogen screens, and current leads of the main engine of nuclear fusion devices (such as ITER). They form a cooling circuit through pipelines and cold mass components, and at the same time bear the role of insulation to the ground. The main performance indicators of cryogenic insulators include: 1) Mechanical strength: At low temperatures, insulators need to maintain sufficient mechanical strength to withstand various loads and prevent brittle cracking. 2) Electrical properties: Under low temperature conditions, the electrical properties of insulators such as volume resistivity and electrical strength should remain stable to ensure insulation performance. 3) Low temperature resistance: Insulator materials should have good low temperature resistance and be able to maintain their physical and chemical properties in low temperature environments. 4) Airtightness: For certain specific applications, such as ITER epoxy composite axial insulators, good low temperature airtightness is required to ensure sealing and airtightness at low temperatures. 5) Impact resistance: Insulators should be able to withstand low temperature impact and hot and cold cycles to maintain their structural integrity and functional reliability. In order to ensure the safe operation of the nuclear fusion magnet system, all insulators need to undergo multiple rounds of performance verification tests, including hot and cold cycle tests, electrical performance tests, mechanical fatigue tests, and helium tightness tests.

[0069] At present, the research on insulators at home and abroad mainly focuses on the changes in the electrical properties of insulators. Few studies pay attention to the changes in the mechanical properties of insulators, and the corresponding test equipment is even more lacking, which brings many inconveniences to the study of the impact of low temperature extreme environment on the mechanical properties of insulators.

[0070] The insulator for nuclear fusion (BEST) is required to maintain a leakage rate less than 1×10 -9Pa·m 3 / s airtightness, and also requires that the airtightness requirements can be met after mechanical fatigue (2000N tension, 2000N compression, 100Nm bending and 100Nm torque) tests. The existing insulator mechanical performance testing machine only has performance tests for tension and compression functions, and cannot fully evaluate the performance of low-temperature insulators under various loads.

[0071] Based on this, the present invention provides a mechanical testing tool for insulators for nuclear fusion, which is arranged as a replaceable tool structure, and the setting position of the insulator can be changed very conveniently when performing different mechanical performance tests, so that the tool can not only perform tensile and compression performance tests, but also bending and torsional performance tests.

[0072] Existing insulator mechanical property testing machines are mainly divided into two types: vertical and horizontal. Both use hydraulic devices to apply mechanical stress to insulators. However, both vertical and horizontal testing machines are large in size and cannot be placed in a liquid nitrogen dewar, which brings inconvenience to the study of the mechanical properties of low-temperature insulators.

[0073] Based on this, the present invention eliminates the hydraulic device and uses a movable beam to drive the neck tube to move to achieve the force on the insulator, which greatly reduces the size of the tooling, so that the insulator positioning frame and the insulator can be placed in the liquid nitrogen test dewar. In addition, the present invention uses the insulator positioning frame to position the insulator, and according to the arrangement of the insulator and the insulator positioning frame, the liquid nitrogen dewar of different shapes is replaced, so that the insulator and the insulator positioning frame can be placed in the liquid nitrogen dewar.

[0074] The specific embodiments of the present invention are described in detail below in conjunction with the mechanical testing tool for nuclear fusion insulators of the first aspect of the present invention, the mechanical testing platform for nuclear fusion insulators of the second aspect of the present invention, and the mechanical testing method for nuclear fusion insulators of the third aspect of the present invention.

[0075] According to an embodiment of the present invention, in a first aspect, a mechanical testing tool for an insulator for nuclear fusion is provided, Figures 1 to 6 As shown, it includes a central rod 400 , an insulator positioning frame 500 and a connecting structure 700 .

[0076] One end of the center rod 400 is arranged on the detection end of the testing machine, and the other end is connected to the insulator 800 .

[0077] The insulator positioning frame 500 has a first end and a second end, and the center rod 400 moves through the first end of the insulator positioning frame. The insulator positioning frame 500 or the center rod 400 is connected to the force-applying end of the testing machine to apply a load to the insulator 800 through the force-applying end of the testing machine.

[0078] The connection structure 700 is a tensile-compression performance test connection structure, a bending performance test connection structure, or a torsion performance test connection structure. The tensile-compression performance test connection structure, the bending performance test connection structure, and the torsion performance test connection structure can be interchanged.

[0079] When the connection structure 700 is a tensile-compression performance test connection structure, one end of the insulator 800 is coaxially connected to the center rod 400, and the other end of the insulator 800 is connected to the second end of the insulator positioning frame. The tensile-compression performance test connection structure, the insulator positioning frame 500, and the center rod 400 together constitute a tensile-compression performance test tooling.

[0080] When the connection structure 700 is a bending performance test connection structure, one end of the insulator 800 is vertically intersected and connected to the center rod 400, and the other end of the insulator 800 is connected to the insulator positioning frame 500 through the bending performance test connection structure. The bending performance test connection structure, the insulator positioning frame 500 and the center rod 400 together constitute a bending performance test tooling.

[0081] When the connection structure 700 is a torsional performance test connection structure, one end of the insulator 800 is vertically connected to the center rod 400 and is not coplanar with the center rod 400, and the other end of the insulator 800 is connected to the insulator positioning frame 500 through the bending performance test connection structure. The torsional performance test connection structure, the insulator positioning frame 500 and the center rod 400 together constitute a bending performance test tooling.

[0082] The above-mentioned mechanical testing tool for insulators for nuclear fusion uses the connection structure 700 to arrange the insulators 800 in different positions, and the tensile and compression performance test connection structure, the bending performance test connection structure and the torsion performance test connection structure can be replaced with each other. After completing a performance test, the tooling that has been used for performance testing can be removed and replaced with other performance testing tooling, thereby ensuring that the mechanical testing tool for insulators for nuclear fusion can perform tensile, compression, bending and torsion performance tests on the insulators 800 respectively, and can more comprehensively evaluate the performance of low-temperature insulators under various loads, and realize comprehensive detection of the insulators 800.

[0083] In order to facilitate the mechanical property test, flanges are welded at both ends of the insulator 800 by argon arc welding, wherein a first insulator flange 702 is provided at one end of the insulator 800, and a second insulator flange 703 is provided at the other end of the insulator 800, and the second insulator flange 703 has a threaded rod. A center rod connecting flange 701 is provided on the center rod 400.

[0084] As a specific embodiment, the insulator positioning frame 500 includes a first flange 501 (upper flange), a second flange 502 (lower flange) and a support rod 503, wherein a plurality of support rods 503 are provided and connect the first flange 501 and the second flange 502. The first flange 501 is the first end of the insulator positioning frame, and the second flange 502 is the second end of the insulator positioning frame.

[0085] In one embodiment, in combination Figure 1 and Figure 2 As shown, the connection structure 700 is a tensile and compressive performance test connection structure, the insulator first flange 702 is connected to the center rod connection flange 701, the insulator second flange 703 is connected to the insulator positioning frame 500, and then the insulator 800 is coaxially connected to the center rod 400. When the force-applying end of the testing machine applies force to the insulator positioning frame 500 or the center rod 400, the insulator 800 can be driven to stretch or compress, thereby realizing the tensile or compressive performance test of the insulator 800.

[0086] As an alternative embodiment, in combination Figure 3 and Figure 4 As shown, the connection structure 700 is a bending performance test connection structure, which includes a fixed flange 705 and a fixed rod 704. The fixed flange 705 is connected to the first end of the insulator positioning frame and / or the second end of the insulator positioning frame through the fixed rod 704, and the second insulator flange 703 is connected to the fixed flange 705. A plurality of first threaded holes or through holes are provided on the first insulator flange 702, a second threaded hole or through hole is provided on the first flange connecting rod 707, and the center rod 400 is connected to the first insulator flange 702 through the first flange connecting rod 707. More specifically, the center rod 400 is connected to a first threaded hole on the first insulator flange 702 through the first flange connecting rod 707 by bolts or two through holes are connected by pins. The centerline extension line of the center rod 400 intersects the centerline extension line of the insulator 800 at right angles. When the force-applying end of the testing machine applies force to the insulator positioning frame 500 or the center rod 400, the load can be applied to the insulator 800 in a direction perpendicular to the axis of the insulator 800, so that the insulator 800 can bend, thereby realizing the bending performance test of the insulator 800.

[0087] As an alternative embodiment, in combination Figure 5 and Figure 6As shown, the connection structure 700 is a torsion performance test connection structure, which includes a fixed flange 705 and a fixed rod 704. The fixed flange 705 is connected to the first end of the insulator positioning frame and / or the second end of the insulator positioning frame through the fixed rod 704, and the second insulator flange 703 is connected to the fixed flange 705. The center rod 400 is connected to the first insulator flange 702 through the first flange connecting rod 707, and the first insulator flange 702 is connected to the second end of the insulator positioning frame through the second flange connecting rod 708. The first flange connecting rod 707 and the second flange connecting rod 708 are located on the left and right sides of the insulator 800. When the force-applying end of the test machine applies force to the insulator positioning frame 500 or the center rod 400, the load can be applied to the first insulator flange 702 in a direction perpendicular to the axis of the insulator 800, so that the insulator 800 can be twisted, thereby realizing the torsion performance test of the insulator 800.

[0088] In one embodiment, a neck tube 600 is provided on the outer sliding sleeve of the center rod 400, one end of the neck tube 600 is connected to the insulator positioning frame 500, and the other end of the neck tube 600 is connected to a connecting flange 601. The connecting flange 601 is connected to the force-applying end of the testing machine, and the center rod 400 is connected to the fixed end of the testing machine; or the connecting flange 601 is connected to the fixed end of the testing machine, and the center rod 400 is connected to the force-applying end of the testing machine.

[0089] In this embodiment, when the force-applying end of the testing machine drives the center rod 400 or the connecting flange 601 to move, the center rod 400 or the connecting flange 601 applies force to the insulator.

[0090] According to an embodiment of the present invention, in a second aspect, a mechanical testing platform for insulators for nuclear fusion is provided, Figures 1 to 12 As shown, it includes a testing machine, a mechanical testing tool for insulators for nuclear fusion and a cryogenic box 200. The mechanical testing tool for insulators for nuclear fusion is arranged on the testing machine. The cryogenic box 200 is arranged on the testing machine to provide a low temperature environment for the insulator 800.

[0091] The above-mentioned mechanical testing platform for insulators for nuclear fusion can not only test the mechanical properties of insulators at room temperature, but also test the mechanical properties of insulators at low temperature. When testing the mechanical properties of insulators at low temperature, the insulator 800 can be arranged in a low temperature box 200, and the insulator 800 can be tested for mechanical properties in the low temperature box 200. This embodiment solves the problem that the mechanical properties of low-temperature insulators cannot be tested in a low temperature environment. Through this platform, various loads (tension, compression, bending, torsion, fatigue) tests of low-temperature insulators at room temperature and low temperature can be tested, and their low temperature resistance and impact resistance can be tested at the same time, which provides method guidance for obtaining effective and reliable characterization of low-temperature insulators and meets my country's demand for mechanical property data of low-temperature materials such as low-temperature insulators, provides guarantee for the safe and reliable operation of nuclear fusion devices, and ensures the information security of my country's core materials in the service of aerospace military projects.

[0092] In one embodiment, in combination Figures 7 to 11 As shown, the testing machine is a static electronic universal testing machine 100. The testing machine includes a support frame 101, a base 102 and a first force sensor 103. The support frame 101 includes a frame body, a fixed beam 1001 and a movable beam 1002. The movable beam 1002 is slidably arranged on the frame body. The movable beam 1002 is the force-applying end of the static electronic universal testing machine. The movable beam 1002 is connected to the connecting flange 601. The base 102 is arranged at the bottom of the support frame 101, and the low-temperature box 200 is arranged on the base 102. The first force sensor 103 is arranged at the bottom of the fixed beam 1001 of the testing machine. The first force sensor 103 is the detection end of the static electronic universal testing machine. The center rod 400 is connected to the first force sensor 103, which is used to monitor and control the load of the insulator 800 in real time.

[0093] In this embodiment, the movable beam 1002 drives the connecting flange 601, the neck tube 600 and the insulator positioning frame 500 to be lifted and lowered, and then the first flange 501 of the insulator positioning frame 500 is applied with force through the neck tube 600 to transfer the load to the insulator 800. In this embodiment, the hydraulic device is eliminated, and the movable beam 1002 is used to drive the neck tube 600 to move, so as to realize the force application on the insulator, which greatly reduces the size of the tooling, so that the insulator positioning frame and the insulator can be placed in the liquid nitrogen test dewar. In addition, in this embodiment, the insulator positioning frame 500 is used to position the insulator 800, and according to the arrangement of the insulator 800 and the insulator positioning frame 500, the liquid nitrogen dewar of different shapes is replaced, so that the insulator and the insulator positioning frame can be placed in the liquid nitrogen dewar.

[0094] As an alternative embodiment, in combination Fig.12As shown, the testing machine is an electro-hydraulic servo dynamic fatigue testing machine 300. The testing machine includes a frame 301, an actuator 302 and a fixed frame 304. The actuator 302 is arranged on the frame 301 and connected to the center rod 400. The actuator 302 is the force-applying end of the testing machine. The fixed frame 304 is arranged on the frame 301. The fixed frame 304 is the fixed end of the testing machine. The fixed frame 304 is connected to the connecting flange 601. The second force sensor 303 is arranged at the connection between the center rod 400 and the actuator 302. The actuator 302 of this embodiment can apply a load to the center rod 400, and the reciprocating motion of the actuator 302 realizes the loading of tensile, compressive, torsion and bending fatigue loads.

[0095] The use of a cryogenic refrigerator to obtain extremely low temperature conditions requires very complex equipment and greatly increases the cost, and the cooling rate is slow, and the sample cannot be accurately controlled to -196°C. In order to solve this technical problem, in one embodiment, the cryogenic box 200 is a liquid nitrogen test dewar. The advantage of using a liquid nitrogen dewar in this embodiment is that it is convenient, simple and quick to obtain an extremely low temperature condition of -196°C. And using the liquid nitrogen immersion cooling method, the sample can be quickly and accurately cooled to a liquid nitrogen temperature of -196°C, with small temperature fluctuations, a simple dewar, and cheap liquid nitrogen, and low experimental costs.

[0096] In one embodiment, the liquid nitrogen test dewar is cylindrical or rectangular. The liquid nitrogen test dewar can be replaced according to the performance test type, so that this embodiment can meet different performance test types.

[0097] The liquid nitrogen test Dewar comprises an outer cylinder and an inner cylinder, and a hollow interlayer is formed between the outer cylinder and the inner cylinder.

[0098] In a preferred embodiment, a self-sealing vacuum valve is installed on the cylindrical test dewar, wherein the hollow interlayer is a high vacuum interlayer, which is evacuated to a high vacuum state before the experiment, and a high vacuum multilayer insulation material (MLI) is arranged in the hollow interlayer. Multilayer insulation materials have excellent insulation properties under high vacuum environment. The structure of multilayer insulation materials consists of alternating reflective layers and spacer layers, and its internal heat transfer is divided into radiation heat exchange, residual gas heat conduction and solid heat conduction. The reflective layer of the multilayer insulation material is usually made of or coated with a material with high reflectivity and low emissivity, so the radiant heat from the previous layer can be partially reflected by the radiation screen of the current layer, and the remaining energy is transferred to the next layer and reflected again. The spacer layer is mainly composed of materials with low thermal conductivity, such as glass fiber, nylon, wire mesh and foam, etc., which reduces the solid heat conduction between adjacent reflective layers. Multilayer insulation materials are mostly used in high vacuum environments to avoid convective heat transfer. Multilayer insulation materials mainly use aluminum-plated polyester film as a reflective layer and polyester mesh as a spacer layer. Activated carbon may also be arranged in the hollow interlayer to absorb trace gases in the hollow interlayer and maintain a long-term vacuum in the hollow interlayer.

[0099] In a preferred solution, a hollow interlayer is formed between the outer cylinder and the inner cylinder of the rectangular test Dewar, and foaming material and / or reinforcing ribs are arranged in the hollow interlayer, which solves the problem that the rectangular liquid nitrogen Dewar is deformed and cannot be used when the conventional liquid nitrogen Dewar is evacuated, and the foaming material has a good thermal insulation effect.

[0100] In one embodiment, the liquid nitrogen test dewar is open at the top, and there is a certain amount of liquid nitrogen consumption. Liquid nitrogen needs to be added during the test to ensure that the insulator is completely immersed in liquid nitrogen. Therefore, this embodiment uses a liquid nitrogen dewar with better thermal insulation performance to reduce liquid nitrogen consumption. In addition, the liquid nitrogen test dewar of this embodiment supplies liquid nitrogen through a mobile liquid nitrogen dewar 900, and the mobile liquid nitrogen dewar 900 is arranged on the side of the support frame 101.

[0101] The mechanical testing platform and method for the insulator for nuclear fusion of the present invention are described in detail below in combination with tensile and compression performance tests, bending performance tests, torsional performance tests, and dynamic fatigue tests.

[0102] 1. Tensile and compression performance test

[0103] The principle of BEST insulator room temperature and low temperature tensile and compressive load performance test is as follows Figure 2 As shown, one end of the insulator is fixed and the other end is directly applied with tensile and compressive loads.

[0104] The connecting flange 601 is fixed to the lower side of the movable beam 1002 by bolts. The two ends of the neck tube 600 are respectively threadedly connected to the connecting flange and the first flange 501. The first flange 501 and the second flange 502 are fixedly connected by several support rods 503 and nuts.

[0105] The cryogenic insulator is located between the first flange 501 and the second flange 502, wherein one end of the insulator, i.e. the lower flange of the insulator, has a threaded rod and passes through the second flange 502, and is connected to the bottom flange of the test bracket through a nut, and the other end is connected to the center rod through the center rod connecting flange threaded rod, and the center rod connecting flange and the upper flange of the insulator are fastened and connected by bolts. It should be ensured that the insulator and the center rod are on the same axis.

[0106] By driving the movable beam 1002 of the testing machine to move up and down, the insulator is loaded with tensile and compressive loads. The computer controls the speed of applying the tensile end force load.

[0107] Among them, a cylindrical liquid nitrogen test dewar is used to enable the cryogenic insulator to achieve liquid nitrogen temperature testing. The tensile and compression test fixtures are placed inside the liquid nitrogen test dewar. Liquid nitrogen is injected from the mobile liquid nitrogen dewar into the liquid nitrogen test dewar to completely immerse the cryogenic insulator. After the cryogenic insulator reaches a temperature of 77K, low-temperature tensile and compression fatigue tests are performed.

[0108] The steps of tensile fatigue test at room temperature are as follows:

[0109] S1. Assembly and zeroing;

[0110] S2. The movable beam is loaded to F1 at a specific speed, maintained for 5 min, and then restored to 0 N at the same speed, maintained for 5 min;

[0111] S3. Repeat step S2 and perform 25 tensile cycle fatigue tests.

[0112] The compression fatigue test steps are as follows:

[0113] S10. Assembly and zeroing;

[0114] S20. The movable beam is loaded to F2 at a specific speed, maintained for 5 min, and then restored to 0 N at the same speed, maintained for 5 min;

[0115] S30. Repeat step S20 to perform 25 compression cycle fatigue tests.

[0116] Tensile and compression fatigue tests at low temperatures:

[0117] The insulator was immersed in liquid nitrogen and cooled to 77K. The above steps were repeated to perform tensile and compressive fatigue tests at 77K in turn.

[0118] 2. Bending performance test

[0119] The structural diagram of the bending performance test is as follows Figure 3 , Figure 4 , Figure 8 and Fig. 9 As shown. The electronic universal testing machine and the center rod have the same structure as those in the tensile and compression performance tests, and will not be repeated. The difference lies in the bending test fixture. The first flange 501 is threadedly connected to the neck tube, and the first flange 501 and the second flange 502 are fixedly connected through several support rods and nuts. The fixed flange is connected to the upper flange and the lower flange through nuts through the fixing rod, and the fixed flange is perpendicular to the first flange 501 and the second flange 502. The first flange 501 of the low-temperature insulator is fixed to the fixed flange by bolts, and the upper part of the second flange 502 at the other end is connected to the center connecting rod by bolts or pins. The center connecting rod 706 is threadedly connected to the center rod. The low-temperature insulator should be perpendicular to the center rod after installation. The bending load on the insulator is loaded by driving the second flange 502 of the testing machine up and down.

[0120] The bending tester is installed in a rectangular liquid nitrogen tank. Liquid nitrogen is injected into the rectangular liquid nitrogen tank and the low-temperature insulator is immersed in the tank to make it reach 77K before the bending performance test is performed. Foam material can be used to fill the inner and outer walls of the rectangular liquid nitrogen tank.

[0121] The steps of bending fatigue test at room temperature are as follows:

[0122] S100. Assembly and zeroing;

[0123] S200. According to the design length L1 from the fixed point to the stretching point in the test device, the length L2 of the insulator itself, the corresponding bending moment is M1, M1 = F3 * L1, the size of F3 can be calculated;

[0124] S300. The movable beam is loaded to F3 at a specific speed (taking 10 minutes), maintained for 5 minutes, and restored to 0N at the same speed, maintained for 5 minutes;

[0125] S400. Repeat step S300 to perform 25 bending cycle fatigue tests.

[0126] The steps of bending fatigue test at low temperature are as follows:

[0127] S100'.Assembly and zeroing;

[0128] S200'. According to the design length L1 from the fixed point to the stretching point in the test device, the length L2 of the insulator itself, the corresponding bending moment is M1, M1 = F3 * L1, the size of F3 can be calculated;

[0129] S300'. Immerse the insulator in liquid nitrogen and cool it down to 77K;

[0130] S400'. The movable beam is loaded to F3 at a specific speed (taking 10 minutes), maintained for 5 minutes, and restored to 0N at the same speed, maintained for 5 minutes;

[0131] S500'. Repeat step S300' and perform 25 bending cycle fatigue tests.

[0132] 3. Torsion performance test

[0133] The structural diagram of the torsion performance test is as follows Figure 5 , Figure 6 , Fig.10 , Fig.11As shown. The other parts are the same as the bending performance test, and the torsion test fixture is slightly different from the bending performance test fixture. Among them, the central connecting rod is located on one side of the second flange of the insulator, and is connected to one side of the second flange of the insulator by bolts or pins. One end of the second flange connecting rod 708 is connected to the other side of the first flange of the insulator by bolts or pins, and the other end of the second flange connecting rod 708 is fixed to the second flange 502 with a nut. The holes on both sides of the second flange 703 of the insulator should be on the same horizontal plane as the insulator. The torsion load on the insulator is loaded by driving the movable beam 1002 in the test machine up and down.

[0134] The above-mentioned tools are all made of stainless steel 304 or stainless steel 316, which ensures the strength of mechanical experiments at low temperatures.

[0135] The low temperature torsion fatigue test steps are as follows:

[0136] S1000. Assembly and zeroing;

[0137] S2000. Calculate the size of F4 according to the moment: F4 = M1 / L2, where L2 is the distance from the center of the central connecting rod bolt hole to the center of the second flange connecting rod bolt hole;

[0138] S3000. Soak the insulator in liquid nitrogen and cool it down to 77K.

[0139] S4000. Load to F4 at a specific compression speed (10 minutes), hold for 5 minutes, return to 0N at the same speed, hold for 5 minutes;

[0140] S5000. Repeat step S3000 and perform 25 torsional cycle fatigue tests.

[0141] 4. Dynamic fatigue test

[0142] By transplanting the tensile, compression, torsion and bending tooling to the electro-hydraulic servo dynamic fatigue testing machine, the tensile, compression, torsion and bending fatigue load tests can be completed. Among them, the middle crossbeam is fixed, the actuator 302 is connected to the center rod 400, and the reciprocating motion of the actuator 302 realizes the loading of tensile, compression, torsion and bending fatigue loads. Fig.12 It is a structural schematic diagram of a torsion test fixture installed on an electro-hydraulic servo dynamic fatigue testing machine.

[0143] Low temperature 77K fatigue test steps:

[0144] 1) Tensile fatigue test: assemble, adjust to zero, and perform fatigue tensile test for a specified number of times at 77K, with a maximum load of F1 / 2, a minimum load of F1 / 20, and a frequency of 1.25Hz;

[0145] 2) Compression fatigue test: assemble, adjust to zero, and perform fatigue compression test for a specified number of times at 77K, with a maximum load of F2 / 2, a minimum load of F2 / 20, and a frequency of 1.25Hz;

[0146] 3) M1 / 2 bending fatigue test: assemble, adjust to zero, and perform fatigue bending test for a specified number of times at 77K, with maximum load F3 / 2, minimum load F3 / 20, and frequency 1Hz;

[0147] 4) M1 / 2 torsion fatigue test: assembly, zeroing, fatigue torsion test for a specified number of times at 77K, maximum load F4 / 2, minimum load F4 / 20, frequency 1.2Hz. The specific method of torsion fatigue test is: by installing the torsion fatigue test fixture and insulator on the fatigue testing machine, immersing the insulator in liquid nitrogen, when the temperature reaches 77K, the upper computer sets the corresponding parameter steps for fatigue test.

[0148] When performing low-temperature tensile and compression fatigue tests and / or bending fatigue tests and / or torsional fatigue tests and / or dynamic fatigue tests, the insulator 800 is immersed in liquid nitrogen to cool the insulator 800 to 77K.

[0149] The reason for making the insulator 800 reach a temperature of 77K is that the cryogenic insulator is used as an insulating channel for cryogenic liquids such as liquid nitrogen in nuclear fusion applications, and liquid nitrogen flows through the insulator to maintain electrical insulation at both ends of the insulator. Therefore, when performing mechanical testing, it is necessary to immerse it in liquid nitrogen to reach the liquid nitrogen temperature of 77K.

[0150] The method for judging that the insulator 800 has cooled to 77K is:

[0151] The insulator 800 is completely immersed in liquid nitrogen, and it is observed that the liquid nitrogen does not boil violently, which means that the sample has been cooled to the liquid nitrogen temperature of 77 K. Since the temperature of liquid nitrogen under atmospheric pressure is -196 ° C, as long as the liquid nitrogen completely immerses the insulator, it can be considered that the insulator temperature is equivalent to the liquid nitrogen temperature.

[0152] Alternatively, the temperature of the insulator 800 is monitored by a thermometer installed near the insulator 800. The thermometer is a rhodium iron thermometer, a platinum resistance thermometer, etc., connected to a temperature display instrument for real-time viewing of the displayed temperature, and the thermometer is placed at the same height as the insulator.

[0153] The present invention can be applied to static tensile, compression, bending, and torsion mechanical performance tests at room temperature and 77K for low-temperature insulators for nuclear fusion, as well as dynamic tensile, compression, bending, and torsion fatigue performance tests, service life assessment, and hot and cold cycle tests. It can also be applied to low-temperature static and dynamic mechanical testing, mechanical fatigue testing, low-temperature resistance testing, and hot and cold shock resistance testing of other low-temperature structural components. Its tooling installation and replacement are simple, convenient, and fast, and it matches the static electronic universal testing machine and the electro-hydraulic servo dynamic fatigue testing machine, and can comprehensively evaluate the mechanical properties, low-temperature resistance, and hot and cold shock resistance of low-temperature insulators. It provides methodological guidance for obtaining effective and reliable characterization of low-temperature insulators, meets my country's demand for mechanical performance data of low-temperature materials such as low-temperature insulators, provides guarantees for the safe and reliable operation of nuclear fusion devices, and ensures the information security of my country's core materials in the service of aerospace military projects.

[0154] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A mechanical testing tool for insulators for nuclear fusion, characterized in that: include: A center rod (400), one end of which is arranged on the detection end of the testing machine, and the other end of which is connected to the insulator (800); An insulator positioning frame (500) has an insulator positioning frame first end and an insulator positioning frame second end, and the center rod (400) movably passes through the insulator positioning frame first end; the insulator positioning frame (500) or the center rod (400) is connected to a force-applying end of a testing machine so as to apply a load to the insulator (800) through the force-applying end of the testing machine; The connection structure (700) is a tensile-compression performance test connection structure, a bending performance test connection structure, or a torsion performance test connection structure. The tensile-compression performance test connection structure, the bending performance test connection structure, and the torsion performance test connection structure can be replaced with each other. When the connection structure (700) is a tensile-compression performance test connection structure, one end of the insulator (800) is coaxially connected to the center rod (400), and the other end of the insulator (800) is connected to the second end of the insulator positioning frame. When the connection structure (700) is a tensile-compression performance test connection structure, one end of the insulator (800) is coaxially connected to the center rod (400), and the other end of the insulator (800) is connected to the second end of the insulator positioning frame. 00) is a bending performance test connection structure, one end of the insulator (800) is vertically connected to the center rod (400), and the other end of the insulator (800) is connected to the insulator positioning frame (500) through the bending performance test connection structure; when the connection structure (700) is a torsion performance test connection structure, one end of the insulator (800) is vertically connected to the center rod (400) and is not coplanar with the center rod (400), and the other end of the insulator (800) is connected to the insulator positioning frame (500) through the bending performance test connection structure.

2. The nuclear fusion insulator mechanical testing tool according to claim 1, characterized in that: One end of the insulator (800) is provided with a first insulator flange (702), and the other end of the insulator (800) is provided with a second insulator flange (703); and a center rod connecting flange (701) is provided on the center rod (400).

3. The nuclear fusion insulator mechanical testing tool according to claim 2, characterized in that: The connection structure (700) is a tensile and compressive performance test connection structure, the first insulator flange (702) is connected to the center rod connection flange (701), and the second insulator flange (703) is connected to the insulator positioning frame (500).

4. The nuclear fusion insulator mechanical testing tool according to claim 2, characterized in that: The connection structure (700) is a bending performance test connection structure, comprising a fixed flange (705) and a fixed rod (704), wherein the fixed flange (705) is connected to the first end of the insulator positioning frame and / or the second end of the insulator positioning frame via the fixed rod (704), and the second insulator flange (703) is connected to the fixed flange (705); the center rod (400) is connected to the first insulator flange (702) via the first flange connecting rod (707), and the center line extension line of the center rod (400) intersects perpendicularly with the center line extension line of the insulator (800).

5. The nuclear fusion insulator mechanical testing tool according to claim 2, characterized in that: The connection structure (700) is a torsional performance test connection structure, comprising a fixed flange (705) and a fixed rod (704), wherein the fixed flange (705) is connected to the first end of the insulator positioning frame and / or the second end of the insulator positioning frame via the fixed rod (704), and the second insulator flange (703) is connected to the fixed flange (705); the center rod (400) is connected to the first insulator flange (702) via the first flange connecting rod (707), and the first insulator flange (702) is connected to the second end of the insulator positioning frame via the second flange connecting rod (708), and the first flange connecting rod (707) and the second flange connecting rod (708) are located on both sides of the insulator (800).

6. The mechanical testing tool for nuclear fusion insulators according to any one of claims 1 to 5, characterized in that: The central rod (400) is provided with a neck tube (600) on the outer sliding sleeve, one end of the neck tube (600) is connected to the insulator positioning frame (500), and the other end of the neck tube (600) is connected to a connecting flange (601); The connecting flange (601) is connected to the force-applying end of the testing machine, and the center rod (400) is connected to the fixed end of the testing machine; or the connecting flange (601) is connected to the fixed end of the testing machine, and the center rod (400) is connected to the force-applying end of the testing machine.

7. A mechanical testing platform for insulators for nuclear fusion, characterized in that: include: Testing machine; The nuclear fusion insulator mechanical testing tool as described in any one of claims 1 to 5, which is arranged on a testing machine; The low temperature box (200) is arranged on the testing machine and is used to provide a low temperature environment for the insulator (800).

8. The nuclear fusion insulator mechanical testing platform according to claim 7, characterized in that: The testing machine is a static electronic universal testing machine (100); the testing machine comprises: The support frame (101) comprises a frame body, a fixed beam (1001) and a movable beam (1002), wherein the movable beam (1002) is slidably arranged on the frame body, the movable beam (1002) is a force-applying end of a static electronic universal testing machine, and the movable beam (1002) is connected to a connecting flange (601); A base (102) is arranged at the bottom of the support frame (101), and the low temperature box (200) is arranged on the base (102); The first force sensor (103) is arranged at the bottom of the fixed beam (1001) of the testing machine. The first force sensor (103) is the detection end of the static electronic universal testing machine. The center rod (400) is connected to the first force sensor (103).

9. The nuclear fusion insulator mechanical testing platform according to claim 7, characterized in that: The testing machine is an electro-hydraulic servo dynamic fatigue testing machine (300), and the testing machine comprises: Rack(301); An actuator (302) is arranged on the frame (301) and connected to the center rod (400), and the actuator (302) is a force-applying end of the testing machine; A fixing frame (304) is arranged on the frame (301), the fixing frame (304) is a fixed end of the testing machine, and the fixing frame (304) is connected to the connecting flange (601); The second force sensor (303) is arranged at the connection between the central rod (400) and the actuator (302).

10. The nuclear fusion insulator mechanical testing platform according to any one of claims 7 to 9, characterized in that: The low temperature box (200) is a liquid nitrogen test dewar, and the liquid nitrogen test dewar comprises an outer cylinder and an inner cylinder, and a hollow interlayer is formed between the outer cylinder and the inner cylinder; The hollow interlayer is evacuated and / or provided with a high vacuum multilayer insulation material and / or activated carbon; or, the hollow interlayer is provided with a foaming material and / or a reinforcing rib.

11. The nuclear fusion insulator mechanical testing platform according to claim 10, characterized in that: The liquid nitrogen test dewar is supplied with liquid nitrogen via a mobile liquid nitrogen dewar (900), and the mobile liquid nitrogen dewar (900) is arranged beside the support frame (101); And / or, the liquid nitrogen test dewar can be replaced according to the type of performance test.

12. A method for mechanical testing of insulators for nuclear fusion, characterized in that: The method is carried out based on the nuclear fusion insulator mechanical testing platform according to any one of claims 7 to 11, and comprises the following steps: The insulator (800) is installed on the insulator positioning frame (500) through the tensile and compressive performance test connection structure, so that the insulator (800) is coaxially connected with the center rod (400), and a load is applied to the insulator (800) through the force application end of the testing machine, and tensile and compressive fatigue tests at room temperature and low temperature are performed in sequence; and / or, installing the insulator (800) onto the insulator positioning frame (500) through the bending performance test connection structure, so that the insulator (800) is vertically intersected with the center rod (400), applying a load to the insulator (800) through the force application end of the testing machine, and sequentially performing bending fatigue tests at room temperature and low temperature; and / or, installing the insulator (800) on the insulator positioning frame (500) through the torsion performance test connection structure, wherein the insulator (800) is vertically connected to the center rod (400) and is not coplanar with the center rod (400), applying a load to the insulator (800) through the force application end of the testing machine, and sequentially performing torsion fatigue tests at room temperature and low temperature; And / or, the nuclear fusion insulator mechanical testing tool is installed on an electro-hydraulic servo dynamic fatigue testing machine (300), and dynamic fatigue tests of tension, compression, torsion and bending are performed in sequence.

13. The method for mechanical testing of insulators for nuclear fusion according to claim 12, characterized in that: When performing a low-temperature tensile and compressive fatigue test and / or a bending fatigue test and / or a torsional fatigue test and / or a dynamic fatigue test, the insulator (800) is immersed in liquid nitrogen to cool the insulator (800) to 77K; wherein the method for determining that the insulator (800) has been cooled to 77K is as follows: the insulator (800) is completely immersed in the liquid nitrogen, and the liquid nitrogen does not boil violently; or, the temperature of the insulator (800) is monitored by a thermometer installed near the insulator (800).

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