Sample for drop weight tear test and fixing base thereof

Abstract

The utility model relates to a sample for a drop weight tear test and a fixing base of the sample, and belongs to the technical field of drop weight tear tests. The sample is a cuboid, a semicircular notch is formed in the longest edge of the sample, the direction of the notch deviates from the other longest edge of the sample, and the central axis of the notch coincides with the central line of the longest edge. The fixing base comprises a base body, the base body is a cuboid, a square through groove and a clamping groove for clamping the sample are formed in the base body, four fixing blocks are placed in the clamping groove, every two fixing blocks form a group, and the fixing blocks are located at the two ends of the sample respectively. According to the sample with the semicircular notch, the test result of a material with high strength, high hardness and poor toughness can be detected, and when the sample is not fractured, the sample can be easily taken out from the fixed base.

Description

Technical Field

[0001] The utility model relates to the technical field of drop weight tear test, in particular to a sample for drop weight tear test and a fixing base thereof. Background Technique

[0002] The existing drop weight tear test method mainly refers to "GB / T 8363-2018 Test method for drop weight tear of steel", and the specified method is applicable to samples with good plasticity. The samples need to be pressed with V-notch, and the specific dimensions are as Figure 1 shown.

[0003] However, for samples with high strength, high hardness and poor toughness, effective test results are often not obtained. If the V-notch is processed according to the sample shape in the drop weight tear test method, it will cause the sample to crack instantaneously due to poor toughness during the test, and it is not easy to record the energy absorption of the sample during the fracture process. In addition, when pressing the V-notch, the blade is generally made of materials with a hardness of 55HRC to 60HRC. Due to the high hardness of the sample, it is very difficult to press the notch, and sometimes the blade will be damaged. If the drop weight tear test of the non-notch sample is carried out directly without notch pressing, it will cause the sample to be not easy to break, or the fracture point of the sample is uncertain. Moreover, it will also cause the hammer head of the testing machine to be damaged due to the large impact force. In addition, during the sample test process, the sample sometimes bends and does not break, but will be clamped in the fixing base and is not easy to take out.

[0004] Therefore, there is an urgent need for a new notched sample and a fixing base. During the actual test process, the sample can well solve the above problems and better complete the test. Content of the Utility Model

[0005] In view of the above analysis, the utility model aims to provide a sample for drop weight tear test and a fixing base thereof, which can preferably obtain test results and can be taken out.

[0006] The utility model provides a sample for drop weight tear test. The sample is a cuboid, and a semi-circular notch is opened on the longest side. The direction of the notch is away from the other longest side of the sample, and the central axis of the notch coincides with the center line of the longest side.

[0007] Further, the length of the sample is 305±5mm, the width is 76.2±1.5mm, and the thickness t is 10-40mm.

[0008] Further, the chord length of the notch is 80mm-200mm, and the radius R is 50mm-260mm.

[0009] On the other hand, the utility model provides a fixing base, and the sample is clamped in the fixing base;

[0010] The fixed base includes a base, which is a cuboid. A square through-hole and a clamping groove for clamping the sample are provided on the base. A fixing block is placed in the clamping groove. The number of the fixing blocks is four, and two of them form a group, which are respectively located at both ends of the sample.

[0011] Furthermore, the height of the fixing block is higher than the depth of the clamping groove.

[0012] Furthermore, the fixing block is composed of a limiting block and an abutting block, and the limiting block and the abutting block are integrally formed; the abutting block is a cuboid, one side of the abutting block contacts the sample, and the limiting block is fixedly connected to the opposite side of the abutting block contacting the sample.

[0013] Furthermore, a threaded hole is provided at one end of the fixing block away from the clamping groove for installing a lifting lug.

[0014] Furthermore, the fixing block is a cuboid, and the fixing block moves towards or away from the sample.

[0015] Furthermore, a plurality of guide posts are fixedly connected to the fixing block, and a cavity for the guide posts to slide is provided in the base.

[0016] Furthermore, a circular groove is provided at the center of the fixing block, a push rod is connected to the groove, and the push rod is threadedly connected to the base.

[0017] Compared with the prior art, the present utility model can at least achieve one of the following beneficial effects:

[0018] 1. The present utility model provides a sample with a semi-circular notch, which is used in the drop hammer tear test and can detect the test results of materials with high strength, high hardness and poor toughness;

[0019] 2. The present utility model provides a fixed base for clamping and fixing a sample with a semi-circular notch. A threaded hole is provided on the fixing block for installing a lifting lug. When the sample is not broken, the fixing block can be driven by the lifting lug to move away from the clamping groove, and the sample can be taken out smoothly;

[0020] 3. The present utility model provides a fixed base for clamping and fixing a sample with a semi-circular notch. A plurality of guide posts are fixedly connected to the fixing block, and a circular groove is provided at the center of the fixing block. A push rod is connected to the groove, and the push rod is threadedly connected to the base; the push rod drives the fixing block to move towards or away from the sample. When the sample is not broken, the sample can be taken out easily.

[0021] In the present utility model, the above technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present utility model will be described in the subsequent description. Moreover, some advantages can be made obvious from the description or understood by implementing the present utility model. The objectives and other advantages of the present utility model can be achieved and obtained from the content specifically pointed out in the description and the drawings. Description of the Drawings

[0022] The drawings are only for the purpose of showing specific embodiments and are not considered as a limitation to the present utility model. Throughout the drawings, the same reference signs denote the same components.

[0023] Figure 1 It is a schematic diagram of a sample with a V-shaped notch;

[0024] Figure 2 It is a schematic diagram of a sample with a semi-circular notch;

[0025] Figure 3 It is a schematic diagram of the fixing block in Embodiment 3;

[0026] Figure 4 It is a schematic diagram of the fixing base in Embodiment 3;

[0027] Figure 5 It is a schematic diagram of the fixing block in Embodiment 4;

[0028] Figure 6 It is an assembly drawing of the fixing block and the push rod in Embodiment 4;

[0029] Figure 7 It is a top view of the fixing base in Embodiment 4;

[0030] Figure 8 It is an internal structure view of the fixing base in Embodiment 4;

[0031] In the figures, 1. sample; 2. fixing base; 21. base; 211. through groove; 212. clamping groove; 22. fixing block; 221. limiting block; 222. abutting block; 223. threaded hole; 23. guiding column; 24. push rod; 241. groove. Detailed Embodiments

[0032] The preferred embodiments of the present utility model will be specifically described below in conjunction with the drawings. The drawings form a part of the present utility model and are used together with the embodiments of the present utility model to explain the principle of the present utility model, rather than to limit the scope of the present utility model.

[0033] In the drop weight tear test, the V-shaped notch is mainly adopted in "GB / T 8363-2018 Test Method for Drop Weight Tear Test of Steel" (refer to Figure 1)Pressing is applicable to samples with good plasticity. However, for materials with high strength, high hardness and poor toughness, it is very difficult to press the V-notch during pressing, and sometimes the blade will be damaged. If the drop-weight tear test of the notchless sample is carried out directly without notch pressing, it will cause the sample to be not easy to break, or the fracture point of the sample is uncertain. Moreover, it will also cause the hammer head of the testing machine to be damaged due to the large impact force, and finally the test results cannot be obtained well.

[0034] In addition, during the sample test, the sample bends and does not break, is clamped in the fixed base, and it is not easy to take out due to the contact pressure between the sample and the fixed base.

[0035] In order to better test the test results of materials with high strength, high hardness and poor toughness, the present utility model provides a sample for drop-weight tear test. The sample is a cuboid, and a semi-circular notch is opened on the longest side. The direction of the notch is away from the other longest side of the sample, and the central axis of the notch coincides with the center line of the longest side.

[0036] Compared with the prior art, the present utility model changes the V-notch on the sample to a semi-circular notch, and pressing is not required during the production of the sample, so the pressing blade will not be damaged. Most importantly, when the sample is a material with high strength, high hardness and poor toughness, and a V-notch is opened on the sample, during the drop-weight test, stress concentration causes the sample to break instantly and it is not easy to record the absorbed work during the fracture process.

[0037] For materials with high strength, high hardness and poor toughness, the present utility model opens a semi-circular notch on the sample. During the test, the sample is placed perpendicular to the ground, and the semi-circular notch faces the ground. During the drop-weight test, stress concentration can be effectively avoided and the absorbed work cannot be recorded. In addition, the problem that the hammer head is damaged due to the large impact work of the notchless sample is solved.

[0038] Specifically, the length of the sample is 305±5mm, the width is 76.2±1.5mm, and the thickness t is 10-40mm.

[0039] Specifically, the length of the sample is 305±5mm, the width is 76.2±1.5mm, and the thickness t is 20±1mm.

[0040] Specifically, the chord length of the notch is 80mm - 200mm, and the radius R is 50mm - 260mm.

[0041] Specifically, the chord length of the notch is 80±2mm, and the radius R is 50±0.5mm.

[0042] It should be noted that the notch is set to be semicircular mainly to reduce the stress concentration effect. If a U-notch is opened according to the Charpy impact, the stress concentration of brittle samples will still be relatively obvious, and the samples will break instantly, making it impossible to record data.

[0043] The radius R of the notch of the present utility model is 50 mm to 260 mm, the corresponding chord length of the notch is 80 mm to 200 mm, and the height of the notch remains unchanged at 20 mm. Considering that the span of the sample is 254 mm, in order to ensure that the sample can be placed on the base normally and stably, the maximum length is considered to be 200 mm.

[0044] In order to better clamp, fix and facilitate the smooth removal of the sample 1 in the later stage, the present utility model provides a fixed base 2. The fixed base 2 includes a base 21. The base 21 is a cuboid, and a square through groove 211 is opened on the base 21, and a clamping groove 212 for clamping the sample 1 is opened. A fixing block 22 is placed in the clamping groove 212. The number of the fixing blocks 22 is four, and two are in a group, which are respectively located at both ends of the sample 1.

[0045] Compared with the prior art, during the drop weight tear test, in order to make the sample 1 more stable, the sample 1 needs to be placed or fixed in the fixed base 2. However, during the drop weight tear test, sometimes the sample 1 does not break but undergoes serious deformation, and both ends of the sample 1 are firmly clamped in the fixed base 2 and cannot be easily taken out, which may cause the fixed base 2 to be unusable.

[0046] Therefore, the present utility model provides a fixed base 2, which includes a cuboid base 21, and a square through groove 211 is opened at the center of the base 21. Its function is that after the sample 1 breaks, the sample 1 leaks out from the square through groove 211; two clamping grooves 212 are also opened on the base 21, and the clamping grooves 212 are symmetrically arranged with the square through groove 211 as the symmetry center. The function of the clamping grooves 212 is to clamp and fix the sample 1, and the lengths of the two clamping grooves 212 and the square through groove 211 are equal to the length of the sample 1.

[0047] In order to better take out the deformed sample 1 smoothly, fixing blocks 22 are placed in the clamping grooves 212. The fixing blocks 22 are cuboids, and the number of them is four. Two are in a group, which are respectively located at both ends of the sample 1, and the two fixing blocks 22 in each group are symmetrically arranged with the sample 1 as the symmetry center.

[0048] Specifically, the size of the fixing block 22 can be adjusted accordingly according to the size of the sample 1.

[0049] Assembly process: First, fix the base 21 on the drop hammer tear tester, then place the fixing block 22 in the clamping groove 212, with two pieces in a group, for a total of two groups. Then place the sample 1 in the fixing block 22, with the semi-circular notch of the sample 1 facing the ground. The fixing block 22 abuts against the sample 1 to ensure the stability of the sample 1, and the center lines of the hammer head, the sample 1, and the square through groove 211 coincide.

[0050] Test process: Start the drop hammer tear tester. The hammer head makes a free fall motion, and the center of the hammer head lands at the center point of the sample 1. The sample 1 breaks, and the broken sample 1 falls from the square through groove 211. Read the absorbed energy and record the data. Replace the new sample 1 for the next test.

[0051] When the sample 1 does not break and is deformed, the fixing block 22 can be moved to provide enough moving space for the sample 1 so that the sample 1 can be taken out smoothly. Replace the new sample 1 and conduct the test again.

[0052] Specifically, the height of the fixing block 22 is higher than the depth of the clamping groove 212.

[0053] It should be noted that when the height of the fixing block 22 is higher than the depth of the clamping groove 212, a part of the fixing block 22 is inside the base 21, and the other part of the fixing block 22 is outside the base 21. The fixing block 22 exposed outside the base 21 can be used as a clamping handle to facilitate the movement of the fixing block 22.

[0054] Specifically, the fixing block 22 is composed of a limiting block 221 and an abutting block 222, and the limiting block 221 and the abutting block 222 are integrally formed; the abutting block 222 is a cuboid, one side of the abutting block 222 contacts the sample 1, and the limiting block 221 is fixedly connected to the opposite side of the abutting block 222 that contacts the sample 1.

[0055] It should be noted that to make the fixing block 22 more stable, the fixing block 22 is composed of two parts, namely a limiting block 221 and an abutting block 222. The abutting block 222 is a cuboid, one side of the abutting block 222 contacts the sample 1, and the limiting block 221 is fixedly connected to the opposite side of the abutting block 222 that contacts the sample 1.

[0056] The function of the limiting block 221 is to prevent the fixing block 22 from moving in the clamping groove 212, and it can only move in the vertical direction. The shape of the limiting block 221 can be set according to actual needs. The area of the limiting block 221 gradually becomes larger in the direction away from the sample 1 starting from the fixing block 22. For example, triangular, semi-circular. The limiting block 221 can also be composed of two parts. The first part is located between the fixing block 22 and the second part, and the width (or length) of the first part is smaller than the width (or length) of the second part.

[0057] Specifically, a threaded hole 223 is provided at one end of the fixing block 22 away from the clamping groove 212 for installing a lifting lug.

[0058] It should be noted that when the sample 1 is deformed without breaking, the fixing block 22 can be lifted through the lifting lug to provide sufficient moving space for the sample 1, facilitating the removal of the sample. The lifting lug can adopt an existing structure and is not shown in the figure. The lifting lug is threadedly connected to the fixing block 22. When in use, the lifting lug can be installed, and when not in use, the lifting lug can be disassembled.

[0059] Specifically, the fixing block 22 moves towards or away from the sample 1.

[0060] It should be noted that in order to better fix and disassemble the sample 1, the fixing block 22 needs to move towards or away from the sample 1. When it is necessary to fix the sample 1, the fixing blocks 22 on both sides of the sample 1 move towards the sample 1 simultaneously. After contacting the sample 1, the movement stops. When the sample 1 bends without breaking, the fixing blocks 22 on both sides of the sample 1 move away from the sample 1 simultaneously or separately, and the unbroken sample 1 can be taken out.

[0061] Specifically, the fixing block 22 is a cuboid, and a plurality of guide posts 23 are fixedly connected to the fixing block 22, and a cavity for the guide posts 23 to slide is provided in the base 21.

[0062] It should be noted that the fixing block 22 can be a cuboid or a cube and can be designed according to the size of the sample 1. One side of the fixing block 22 contacts the sample 1. A plurality of guide posts 23 are fixedly connected to the fixing block 22. The guide posts 23 are located on the side of the fixing block 22 away from the sample 1. The number of guide posts 23 is at least 2, and a cavity for the guide posts 23 to slide is provided in the base 21. The sliding direction is horizontal and towards or away from the sample 1.

[0063] Specifically, a circular groove 241 is provided at the center of the fixing block 22, a push rod 24 is connected to the groove 241, and the push rod 24 is threadedly connected to the base 21.

[0064] Preferably, a cross bar is fixedly connected to the push rod 24.

[0065] It should be noted that a groove 241 is provided at the center position of the fixing block 22. The groove 241 is located among the guide posts 23 and is circular. A push rod 24 is connected to the groove 241. The push rod 24 is cylindrical. The groove 241 is for the push rod 24 to be inserted and the push rod 24 can rotate. The connection mode of the push rod 24 and the base 21 is threaded connection. Threads are processed on the outer peripheral surface of the push rod 24 (not shown in the figure), and corresponding threads are provided on the base 21. In order to better operate, a cross bar is fixedly connected to the end of the push rod 24 away from the fixing block 22.

[0066] Installation movement process: First, install the fixing blocks 22. There are a total of four fixing blocks 22, two in a group, which are respectively placed in the clamping grooves 212 in the base 21, and install the guide posts 23 on the fixing blocks 22 in the cavities in the base 21. However, the length of the guide posts 23 can be adjusted according to actual needs; then place the sample 1 between the two fixing blocks 22, and move the push rod 24 from the outside of the base 21 towards the sample 1 until it reaches the circular groove 241 of the fixing block 22. The moving method is through threads; the push rod 24 will push the fixing block 22 towards the sample 1 and fix the sample 1, and the distance between the sample 1 and the fixing block 22 can be adjusted as needed.

[0067] When the sample 1 is deformed without breaking, the push rod 24 rotates in the reverse direction, so that the push rod 24 moves away from the fixing block 22, and the fixing block 22 moves along the guide post 23 away from the sample 1. At this time, the distance between the sample 1 and the fixing block 22 increases, and the sample 1 can be taken out smoothly.

[0068] To describe the present invention more clearly, it is further illustrated by the following examples and comparative examples.

[0069] Example 1

[0070] Referring to Figure 2 , the present invention provides a drop hammer tear test sample 1. The sample 1 is a cuboid, with a semi-circular notch opened on the longest side. The direction of the notch is away from the other longest side of the sample 1, and the central axis of the notch coincides with the center line of the longest side. The length of the sample 1 is 305 ± 5 mm, the width is 76.2 ± 1.5 mm, and the thickness t is 20 ± 1 mm. The chord length of the notch is 80 ± 2 mm, and the radius R is 50 ± 0.5 mm.

[0071] The present invention changes the V-shaped notch on the sample 1 to a semi-circular notch. During the production of the sample 1, pressing is not required, so the pressing blade will not be damaged.

[0072] Most importantly, for materials with high strength, high hardness and poor toughness, the present invention opens a semi-circular notch on the sample 1. During the test, the sample 1 is placed perpendicular to the ground, and the semi-circular notch faces the ground. During the drop hammer test, stress concentration can be effectively avoided and the absorbed energy cannot be recorded. In addition, the problem that the hammer head is damaged due to the large impact work of the sample 1 without a notch is solved.

[0073] Example 2

[0074] Referring to Figure 2 and Figure 3, the present utility model provides a fixing base 2 for fixing a sample 1 in a fixed weight drop tear test. The fixing base 2 includes a base 21 which is a cuboid. A square through slot 211 is formed in the base 21, and a clamping slot 212 for clamping the sample 1 is formed. A fixing block 22 is placed in the clamping slot 212. The number of the fixing blocks 22 is four, two in a group, and they are respectively located at both ends of the sample 1.

[0075] Assembly process: First, fix the base 21 on the weight drop tear testing machine, then place the fixing blocks 22 in the clamping slot 212, two in a group, with a total of two groups. Then place the sample 1 in the fixing blocks 22, with the semi-circular notch of the sample 1 facing the ground. The fixing blocks 22 abut against the sample 1 to ensure the stability of the sample 1, and the center lines of the hammer head, the sample 1, and the square through slot 211 coincide.

[0076] Testing process: Start the weight drop tear testing machine. The hammer head makes a free fall motion, and the center of the hammer head falls on the center point of the sample 1. The sample 1 breaks, and the broken sample 1 falls from the square through slot 211. Read the absorbed energy and record the data. Replace the new sample 1 for the next test.

[0077] When the sample 1 does not break but deforms, the fixing blocks 22 can be moved to provide enough moving space for the sample 1 so that the sample 1 can be taken out smoothly. Replace the new sample 1 and conduct the test again.

[0078] Embodiment 3

[0079] Refer to Figure 2 and Figure 3 , the fixing block 22 is composed of a limiting block 221 and an abutting block 222, and the limiting block 221 and the abutting block 222 are integrally formed; the abutting block 222 is a cuboid, one surface of the abutting block 222 contacts the sample 1, and the limiting block 221 is fixedly connected to the opposite surface of the abutting block 222 that contacts the sample 1. The limiting block 221 is composed of two parts. The first part is located between the second part and the abutting block 222. The first part is a cuboid, and the second part is a cylinder. The cross-sectional width of the first part is smaller than the cross-sectional diameter of the second part. A threaded hole 223 is formed at one end of the fixing block 22 away from the clamping slot 212 for installing a lifting lug.

[0080] When the sample 1 does not break but deforms, the fixing block 22 can be lifted by the lifting lug to provide enough moving space for the sample 1, facilitating the removal of the sample. The lifting lug can adopt an existing structure and is not shown in the figure. The lifting lug is threadedly connected to the fixing block 22. When in use, the lifting lug can be installed, and when not in use, the lifting lug can be disassembled.

[0081] Embodiment 4

[0082] Refer toFigure 5 and Figure 6 The fixing block 22 is a cuboid. A plurality of guide posts 23 are fixedly connected to the fixing block 22, and a cavity for the guide posts 23 to slide is formed in the base 21. A circular groove 241 is formed at the center of the fixing block 22. A push rod 24 is connected to the groove 241, and the push rod 24 is threadedly connected to the base 21. A cross bar is fixedly connected to the push rod 24.

[0083] Refer to Figure 7 and Figure 8 For the installation movement process: First, install the fixing block 22. There are a total of four fixing blocks 22, two in a group, which are respectively placed in the clamping grooves 212 in the base 21, and the guide posts 23 on the fixing block 22 are installed in the cavities in the base 21. However, the length of the guide posts 23 can be adjusted according to actual needs; then place the sample 1 between the two fixing blocks 22, and move the push rod 24 from the outside of the base 21 towards the sample 1 until it reaches the circular groove 241 of the fixing block 22. The moving method is through threading; the push rod 24 will push the fixing block 22 towards the sample 1 and fix the sample 1, and the distance between the sample 1 and the fixing block 22 can be adjusted according to needs.

[0084] When the sample 1 deforms without breaking, the push rod 24 rotates in the reverse direction, causing the push rod 24 to move away from the fixing block 22, and the fixing block 22 moves away from the sample 1 along the guide posts 23. At this time, the distance between the sample 1 and the fixing block 22 increases, and the sample 1 can be taken out smoothly.

[0085] As mentioned above, it is only the preferred specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model should be covered within the protection scope of the present utility model.

Claims

1. A sample for drop weight tear test, characterized in that, The sample (1) is a cuboid, with a semi-circular notch opened on the longest side. The direction of the notch is away from the other longest side of the sample (1), and the central axis of the notch coincides with the center line of the longest side.

2. The sample for the drop weight tear test according to claim 1, wherein The length of the sample (1) is 305 ± 5 mm, the width is 76.2 ± 1.5 mm, and the thickness t is 10 - 40 mm.

3. The sample for drop weight tear test according to claim 1, characterized in that, The chord length of the notch is 80 mm - 200 mm, and the radius R is 50 mm - 260 mm.

4. A fixed base, characterized in that, The sample according to any one of claims 1 - 3 is snap-connected in the fixed base (2); The fixed base (2) includes a base (21). The base (21) is a cuboid, with a square through slot (211) opened on the base (21), and a snap-in groove (212) for snap-connecting the sample (1). A fixing block (22) is placed in the snap-in groove (212). The number of the fixing blocks (22) is four, two in a group, and they are respectively located at both ends of the sample (1).

5. The fixed base according to claim 4, characterized in that, The height of the fixing block (22) is higher than the depth of the snap-in groove (212).

6. The fixed base according to claim 4, characterized in that, The fixing block (22) is composed of a limiting block (221) and an abutting block (222), and the limiting block (221) and the abutting block (222) are integrally formed; the abutting block (222) is a cuboid, one surface of the abutting block (222) contacts the sample (1), and the limiting block (221) is fixedly connected to the opposite surface of the abutting block (222) that contacts the sample (1).

7. The fixed base according to claim 6, characterized in that, A threaded hole (223) is opened at one end of the fixing block (22) away from the snap-in groove (212) for installing a lifting lug.

8. The fixed base according to claim 4, wherein, The fixing block (22) is a cuboid, and the fixing block (22) moves towards or away from the sample (1).

9. The fixed base according to claim 8, characterized in that, A plurality of guide posts (23) are fixedly connected to the fixing block (22), and a cavity for the guide posts (23) to slide is opened on the base (21).

10. The fixed base according to claim 9, characterized in that, A circular groove (241) is opened at the center of the fixing block (22), a push rod (24) is connected to the groove (241), and the push rod (24) is threadedly connected to the base (21).

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