Metal sheet fracture toughness test clamp

Abstract

The utility model discloses a metal sheet fracture toughness test fixture which comprises a base and is characterized in that the base is provided with two clamping devices which are symmetrically arranged at the left end and the right end of the base and used for clamping the same metal sheet; the two lower supporting rollers are symmetrically arranged at the left end and the right end of the base, and each lower supporting roller is located below the clamping position of the clamping device on the same side and used for supporting the metal sheet; and the centering device is detachably arranged in the center of the base and is used for aligning the metal sheet with a slot on the metal sheet in a manner of adjusting the metal sheet left and right. The test fixture is simple in structure, reasonable in design, low in investment cost and convenient to realize, is realized by the existing universal testing machine or fatigue testing machine, and can effectively measure the fracture toughness of the metal sheet.

Description

Technical Field

[0001] The utility model relates to the technical field of metal sheet fracture toughness test, in particular to a metal sheet fracture toughness test fixture. Background Art

[0002] With the continuous upgrading of products, the actual service conditions and requirements of metal materials are constantly improving, and there are also higher requirements for the comprehensive properties of metal materials such as strength, plasticity and toughness.

[0003] When evaluating the toughness of metal materials, one of the important indicators is the fracture toughness K of the material. IC . K IC It is a mechanical performance index for evaluating unstable fracture of materials with cracks. It has high requirements on the accuracy and support method of the sample loading system.

[0004] The current K IC The test is quite mature, but the thickness of the metal that can be measured is required to be above 5mm. For metal sheets below 5mm, due to their small size, they are easy to deform as a whole when subjected to force, so the fracture toughness K IC It is also inaccurate. At present, the application demand and requirements of metal sheets below 5 mm are getting higher and higher, and their fracture toughness needs to be evaluated. If the traditional method is still used, the accurate fracture toughness of metal sheets cannot be obtained. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a metal sheet fracture toughness test fixture in view of the deficiencies in the above-mentioned prior art, which is implemented by relying on an existing universal testing machine or fatigue testing machine. A clamping device is used to firmly fix the metal sheet on the test bench of the testing machine, so that no overall deformation occurs during the test, thereby being able to effectively measure the fracture toughness of the metal sheet.

[0006] In order to solve the above technical problems, the technical solution adopted by the utility model is: a metal sheet fracture toughness test fixture, including a base, characterized in that the base is provided with:

[0007] Two clamping devices are symmetrically arranged at the left and right ends of the base, and are used to clamp the same metal sheet;

[0008] Two lower support rollers are symmetrically arranged at the left and right ends of the base, and each of the lower support rollers is located below the clamping position of the clamping device on the same side, for supporting the metal sheet;

[0009] A centering device is detachably arranged at the center of the base and is used to align the metal sheet with the slot on the metal sheet by adjusting the metal sheet left and right.

[0010] The above-mentioned metal sheet fracture toughness test fixture is characterized in that: the clamping device includes two front-to-back symmetrical clamping parts, each of which is in a "T" shape consisting of a vertical rod and a horizontal rod, the bottoms of the vertical rods are respectively slidably connected to the base, and the vertical rods of the two clamping parts are connected by springs. The opposite rod heads of the two horizontal rods are used to clamp the metal sheet.

[0011] The above-mentioned metal sheet fracture toughness test fixture is characterized in that: a groove for accommodating the vertical rod is provided on the base.

[0012] The above-mentioned metal sheet fracture toughness test fixture is characterized in that the lower support roller is located between the two vertical rods and has no contact with the spring between the two vertical rods.

[0013] The above-mentioned metal sheet fracture toughness test fixture is characterized in that the lower support roller is detachably connected to the base.

[0014] The above-mentioned metal sheet fracture toughness test fixture is characterized in that: the centering device comprises:

[0015] a base, the bottom of which is detachably connected to the base;

[0016] A centering tip is arranged on the base and points toward the metal sheet.

[0017] The above-mentioned metal sheet fracture toughness test fixture is characterized in that: a through groove running through the base in the front-to-back direction is opened on the upper surface of the base, and the base is detachably connected to the bottom of the through groove.

[0018] The above-mentioned metal sheet fracture toughness test fixture is characterized in that the groove depth of the through groove is equal to the height of the base.

[0019] Compared with the prior art, the utility model has the following advantages:

[0020] The utility model is realized by relying on the existing universal testing machine or fatigue testing machine. The metal sheet is firmly fixed by using the clamping device and the lower support roller on the test bench of the testing machine, so that the two ends of the metal sheet are subjected to a stable supporting force, and no tilting and bending will occur before and after the test, so that no overall deformation will occur during the test, so that the fracture toughness of the metal sheet can be effectively measured. At the same time, it is suitable for high-cycle fatigue test and three-point bending test of metal sheets, and can be applied to room temperature and high temperature conditions at the same time; at the same time, the lower support roller of the utility model is a detachable combination design, and the lower support rollers of different specifications and sizes can be replaced according to the thickness of the plate; the tooling of the utility model can realize the three-point bending K of small sample metal sheets with a wall thickness of more than 0.5mm IC test.

[0021] Therefore, relying on the existing universal testing machine or fatigue testing machine, the metal sheet is firmly fixed on the test bench of the testing machine using a clamping device, so that the overall deformation will not occur during the test, so that the fracture toughness of the metal sheet can be effectively measured. It is suitable for the three-point bending K test of small sample metal sheets with a wall thickness of more than 0.5 mm. IC test.

[0022] The technical solution of the utility model is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0024] Figure 2 It is a schematic diagram of the structure of the metal sheet in the utility model.

[0025] Figure 3 This is a schematic diagram of the structure of the clamping device in the utility model.

[0026] Description of reference numerals:

[0027] 1. Base; 2. Through groove; 3. Centering device; 4. Lower support roller; 5. Clamping device; 5-1. Cross bar; 5-2. Vertical bar; 6. Metal sheet; 7. Upper pressure head; 8. Load sensor; 9. Slot; 10. Spring. DETAILED DESCRIPTION

[0028] like Figure 1-3 As shown, the utility model provides a metal sheet fracture toughness test fixture, comprising a base 1, on which are provided:

[0029] Two clamping devices 5 are symmetrically arranged at the left and right ends of the base 1, and are used to clamp the same metal sheet 6;

[0030] Two lower support rollers 4 are symmetrically arranged at the left and right ends of the base 1, and each of the lower support rollers 4 is located below the clamping position of the clamping device 5 on the same side, for supporting the metal sheet 6;

[0031] The centering device 3 is detachably disposed at the center of the base 1 and is used to align the metal sheet 6 with the slot 9 on the metal sheet 6 by adjusting the metal sheet 6 left and right.

[0032] When in use, the test fixture provided by the utility model is placed on the test bench of the testing machine (universal testing machine or fatigue testing machine), the metal sheet (test specimen) is placed on the lower support roller 4 on the base 1, and the metal sheet 6 is adjusted left and right using the centering device 3 to ensure that the slot 9 on the metal sheet 6 is in the middle of the fixture. After adjustment, the two ends of the metal sheet are clamped and fixed using two clamping devices 5. Finally, the testing machine is started to pressurize the metal sheet downward, so that the metal sheet 6 is fractured along the slot 9 while being pressed, and the fracture toughness is calculated according to the testing machine.

[0033] Before starting the test, in order to calculate the fracture toughness, it is necessary to measure the metal sheet 6 to obtain the size of the metal sheet. The size of the metal sheet 6 includes the groove depth a (unit mm), the sample thickness B (unit mm, generally twice the width) and the sample width W (unit mm). At the same time, it is also necessary to measure the span S (unit mm) of the metal sheet 6. The span S of the metal sheet 6 is the distance between the left and right lower rollers 4. At the same time, it is necessary to make a groove on the surface of the metal sheet 6, preferably in the center of the surface, so that when the metal sheet 6 is pressurized, it will break along the groove 9. After performing the above operations, with these data, you can start to use the testing machine to measure the fracture toughness of the metal sheet 6, and immediately perform a three-point bending K IC test.

[0034] In the present invention, the upper pressure head 7 in the testing machine has a load sensor 8 at the bottom, and the upper pressure head 7 presses the metal sheet 6 so that the metal sheet 6 breaks along the slot 9. At the same time, the maximum force F applied by the upper pressure head 7 is collected, and finally, the following calculation formula is used to calculate

[0035]

[0036] Among them, K IC is the fracture toughness, that is, the fracture toughness of the metal sheet (metal sheet).

[0037] In order to better realize the utility model, the clamping device 5 is further limited and optimized. The clamping device 5 includes two front-to-back symmetrical clamping parts, each of which is in a "T" shape, consisting of a vertical rod 5-2 and a horizontal rod 5-1. The bottoms of the vertical rods 5-2 are respectively slidably connected to the base 1, and the vertical rods 5-2 of the two clamping parts are connected by springs 10. The opposite rod heads of the two horizontal rods 5-1 are used to clamp the metal sheet 6.

[0038] When in use, the metal sheet 6 is clamped by the rod heads opposite to the crossbar 5-1. Since the clamping part and the base 1 are connected by the spring 10, the clamping part can move on the base 1. This may cause the slight clamping to be not stable enough. Therefore, the utility model provides a groove for accommodating the vertical rod 5-2 on the base 1. In this way, the range of movement of the vertical rod 5-2 can be fixed, so that the stability of the clamping can be increased on the basis of the clamping.

[0039] Meanwhile, the lower support roller 4 of the utility model is located between the two vertical rods 5-2 and has no contact with the spring 10 between the two vertical rods 5-2. The spring 10 can be parallel to the lower support roller 4, or a hole can be opened on the lower support roller 4 for the spring 10 to pass through. The spring 10 and the lower support roller 4 do not affect each other, so that the elasticity of the spring 10 can always be kept at the optimum.

[0040] In order to better implement the present invention, the lower support roller 4 of the present invention can be detachably connected to the base 1, so that the lower support rollers of different specifications and sizes can be replaced according to the thickness of the metal sheet 6.

[0041] In order to better implement the present invention, the centering device 3 of the present invention includes: a base and a centering tip, wherein the base has a bottom which is detachably connected to the base 1; and the centering tip is arranged on the base and points to the metal sheet 6.

[0042] When in use, the centering tip and the slot 9 and the pressing head 7 are located on the same vertical straight line, which means that the left-right adjustment of the metal sheet 6 is completed.

[0043] The upper surface of the base 1 in the utility model is provided with a through slot 2 that runs through the base 1 in the front-to-back direction, and the base is detachably connected to the bottom of the through slot 2. In this way, the centering device 3 does not occupy the position on the surface of the base 1, so that the metal sheet can be clamped lower and more firmly.

[0044] Optimally, the depth of the through slot 2 is equal to the height of the base. The base is detachably connected to the bottom of the through slot 2 by sliding forward and backward on a slide rail. This makes it easy to remove the centering device 3 during testing, and the sliding method is very convenient.

[0045] In order to better use the clamp of the present invention in a testing machine, a fixing device for fixing on the testing machine is provided on the upper surface of the base 1 .

[0046] After a large number of tests, the metal sheet fracture toughness test fixture provided by the utility model can accurately measure the fracture toughness test of metal sheets with a thickness as low as 0.5mm when conducting fracture toughness tests on metal sheets, and the error is controllable. Compared with the traditional fracture toughness test directly on the testing machine, which requires the thickness of the metal sheet to be 5mm, this is a breakthrough.

[0047] The above is only a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Any simple modification, change and equivalent structural change made to the above embodiments according to the technical essence of the present invention shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A metal sheet fracture toughness test fixture, comprising a base (1), characterized in that: The base (1) is provided with: Two clamping devices (5) are symmetrically arranged at the left and right ends of the base (1) and are used to clamp the same metal sheet (6); Two lower support rollers (4) are symmetrically arranged at the left and right ends of the base (1), and each of the lower support rollers (4) is located below the clamping position of the clamping device (5) on the same side, and is used to support the metal sheet (6); A centering device (3) is detachably arranged at the center of the base (1) and is used to align the metal sheet (6) with the slot (9) on the metal sheet (6) by adjusting the metal sheet (6) left and right.

2. A metal sheet fracture toughness test fixture according to claim 1, characterized in that: The clamping device (5) comprises two front-to-back symmetrical clamping parts, each of which is formed into a "T" shape by a vertical rod (5-2) and a horizontal rod (5-1), the bottoms of the vertical rods (5-2) are respectively slidably connected to the base (1), the vertical rods (5-2) of the two clamping parts are connected by a spring (10), and the opposite rod heads of the two horizontal rods (5-1) are used to clamp the metal sheet (6).

3. A metal sheet fracture toughness test fixture according to claim 2, characterized in that: The base (1) is provided with a groove for accommodating the vertical rod (5-2).

4. A metal sheet fracture toughness test fixture according to claim 2 or 3, characterized in that: The lower support roller (4) is located between the two vertical rods (5-2) and has no contact with the spring (10) between the two vertical rods (5-2).

5. A metal sheet fracture toughness test fixture according to claim 1, characterized in that: The lower support roller (4) is detachably connected to the base (1).

6. A metal sheet fracture toughness test fixture according to claim 1, characterized in that: The centering device (3) comprises: A base, the bottom of which is detachably connected to the base (1); A centering tip is arranged on the base and points toward the metal sheet (6).

7. A metal sheet fracture toughness test fixture according to claim 6, characterized in that: The upper surface of the base (1) is provided with a through slot (2) which runs through the base (1) in the front-rear direction, and the base is detachably connected to the bottom of the through slot (2).

8. A metal sheet fracture toughness test fixture according to claim 7, characterized in that: The depth of the through groove (2) is equal to the height of the base.

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