A material fracture toughness testing apparatus

Abstract

The utility model embodiment provides a kind of material fracture toughness testing device, it is related to material fracture toughness testing technical field.The testing device includes: support component, loading component and auxiliary positioning mechanism;Auxiliary positioning mechanism includes: pedestal, is placed on two the support roll of described;Pedestal has first plane, and first plane is used to abut with test workpiece;The projection line of first plane on the plane formed by two support rolls is perpendicular to support roll each other.The utility model embodiment provides a kind of material fracture toughness testing device, can ensure that test workpiece axis and three roll axis keep orthogonal relationship, effectively solve the span variation and additional bending moment problem caused by test workpiece pose deviation in traditional method, meet the space geometric constraint condition of fracture toughness test, improve the accuracy and reliability of test data.

Description

Technical Field

[0001] This utility model relates to the field of material fracture toughness testing technology, and in particular to a material fracture toughness testing device. Background Technology

[0002] Fracture toughness, as a core performance indicator characterizing a material's ability to resist crack instability and propagation, is a key quantitative parameter for evaluating material toughness and has significant engineering application value in high-end equipment fields such as aerospace and marine engineering. Traditional fracture toughness testing devices use the three-point bending method, which involves pre-cutting a notch at the bottom of the sample, forming a lower support system with two support rollers, and applying cyclic loads to the upper loading roller to achieve the test. For testing materials such as ceramics, three geometric constraints must be met: (1) the axes of the support rollers and the loading rollers must be parallel; (2) the axes of the two support rollers must be symmetrically distributed relative to the loading roller; (3) the long axis of the sample must be orthogonal to the axes of the three rollers and the pre-cut notch must be located directly below the loading roller. However, current testing methods rely on manual visual positioning, which often leads to sample orientation deviations, specifically manifested in three typical error modes: the span variation caused by the parallel support rollers and loading rollers but the tilt of the sample (e.g., Figure 1 As shown in Figure a), the sample is only orthogonal to the support roller but skewed to the loading roller (as shown in Figure a). Figure 1 (as shown in Figure b), or only satisfying the requirement of being perpendicular to the loading roller but deviating from the orthogonal requirement of the support roller (such as...). Figure 1 (As shown in Figure c). These geometric deviations will introduce additional bending moments, significantly affecting the accuracy and reliability of fracture toughness test data. Summary of the Invention

[0003] To address the technical problem in existing technologies where material fracture toughness testing relies on manual visual positioning, leading to sample orientation deviations and introducing additional bending moments that affect the accuracy and reliability of test data, this invention provides a material fracture toughness testing device. The technical solution is as follows:

[0004] This utility model provides a material fracture toughness testing device, comprising:

[0005] A support assembly includes: a workpiece platform and two support rollers; the support rollers are laterally disposed on the upper surface of the workpiece platform, and the two support rollers are arranged in parallel; the support rollers are used to support the test workpiece.

[0006] The loading assembly includes: a liftable loading roller; the loading roller is laterally positioned above the workpiece platform, and two support rollers are symmetrically arranged about the central axis of the loading roller;

[0007] An auxiliary positioning mechanism includes: a base placed on two support rollers; the base having a first plane for contacting the test workpiece; the first plane being perpendicular to the plane formed by the axes of the two support rollers, and the projection line of the first plane on the plane formed by the axes of the two support rollers being perpendicular to the two support rollers; a first positioning groove at the bottom of the base, wherein the support rollers are inserted into the first positioning groove when the base is placed on the support rollers; and a second positioning groove at the top of the base, located directly below the loading roller, wherein the loading roller is driven to move downward into the second positioning groove when pressure is applied to the test workpiece.

[0008] Optionally, the auxiliary positioning mechanism further includes: two moving components; the moving components include:

[0009] A sliding member is slidably disposed on the base along a first direction; the two sliding members are symmetrically arranged about the central axis of the loading roller.

[0010] A connecting block is disposed below the base. The connecting block is connected to the bottom of the slider and moves with the slider. The bottom of the connecting block is provided with the first positioning groove.

[0011] Optionally, the first plane is provided with scale values ​​along the first direction, and the top of the slider is provided with a first pointer, which points to the scale value to display the moving distance of the first positioning groove.

[0012] Optionally, the auxiliary positioning mechanism further includes:

[0013] The first positioning component has a first slot at its bottom and a second positioning groove at its top; the top of the base has a protrusion located directly below the loading roller, and the protrusion engages with the first slot.

[0014] Optionally, the auxiliary positioning mechanism further includes:

[0015] The second positioning element is slidably disposed on the first plane along the first direction; one side of the second positioning element along the first direction is the second plane, and the second plane is perpendicular to the first plane to form a right angle. When the test workpiece is placed on the support roller, the test workpiece abuts against the first plane and the second plane respectively.

[0016] Fasteners are used to lock the second positioning member onto the base when it comes into contact with the test workpiece.

[0017] Optionally, the first plane has a scale value along the first direction; the second plane has a second pointer, which points to the scale value to display the moving distance of the second positioning element.

[0018] Optionally, the support component further includes:

[0019] Two support seats are slidably disposed on the upper surface of the workpiece platform; the top of the support seats is provided with a receiving groove, and the support roller is placed in the corresponding receiving groove.

[0020] Optionally, the support component further includes:

[0021] A fixing base is provided with a slot; the fixing base is located below the workpiece platform; the bottom of the workpiece platform has a downwardly extending fixing part, which is inserted into the slot.

[0022] The beneficial effects of the technical solution provided by this utility model embodiment include at least the following:

[0023] This utility model provides a material fracture toughness testing device. By setting a first positioning groove and a second positioning groove on the base structure, the spatial orientation of the two support rollers and the loading roller is constrained, ensuring that the axes of the three rollers are parallel. When the test workpiece is placed on the support roller and abuts against the first plane of the base, it can ensure that the axis of the test workpiece is orthogonal to the axis of the three rollers. This effectively solves the problem of span change and additional bending moment caused by the deviation of the test workpiece orientation in traditional methods, meets the spatial geometric constraint conditions of fracture toughness testing, and improves the accuracy and reliability of test data. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a diagram showing the orientation deviation of the test workpiece in a traditional material fracture toughness testing device.

[0026] Figure 2 This is a front view structural schematic diagram of some embodiments of the material fracture toughness testing device provided by this utility model;

[0027] Figure 3 This is the assembly intention of the material fracture toughness testing device provided in some embodiments of this utility model;

[0028] Figure 4This is a rear view structural schematic diagram of the auxiliary positioning mechanism provided in some embodiments of this utility model;

[0029] Figure 5 This is a top view schematic diagram of the auxiliary positioning mechanism provided in some embodiments of this utility model;

[0030] Figure 6 This is a diagram showing the orthogonal relationship between the test workpiece and the axis of the three rollers in some embodiments provided by this utility model.

[0031] Figure label:

[0032] 1-Support assembly; 11-Workpiece platform; 111-Fixing part; 12-Support roller; 13-Support base; 14-Fixing base; 141-Second slot;

[0033] 2-Loading component; 21-Loading roller;

[0034] 3-Auxiliary positioning mechanism; 31-Base; 31a-First plane; 311-First positioning groove; 312-Second positioning groove; 313-Protrusion; 314-Slide groove; 32-Moving component; 321-Sliding member; 322-Connecting block; 33-First positioning member; 331-First slot; 34-Second positioning member; 341-Second plane; 35-Fastener;

[0035] 4 - Scale value; 5 - First pointer; 6 - Second pointer; 100 - Test workpiece. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the described embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0037] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "an," "a," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0038] It should be noted that the terms "up", "down", "left", "right", "front" and "back" used in this utility model are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0039] Figure 2 This is a front view structural schematic diagram of some embodiments of the material fracture toughness testing device provided by this utility model; Figure 3 This is an assembly diagram of a material fracture toughness testing device according to some embodiments of this utility model; Figure 4 This is a rear view structural schematic diagram of the auxiliary positioning mechanism provided in some embodiments of this utility model; Figure 5 This is a top view schematic diagram of the auxiliary positioning mechanism provided in some embodiments of this utility model. (See attached diagram) Figures 2-5This utility model provides a material fracture toughness testing device, comprising: a support assembly 1, a loading assembly 2, and an auxiliary positioning mechanism 3; the support assembly 1 includes: a workpiece platform 11 and two support rollers 12; the support rollers 12 are laterally disposed on the upper surface of the workpiece platform 11, and the two support rollers 12 are arranged in parallel; the support rollers 12 are used to support the test workpiece 100; the loading assembly 2 includes: a liftable loading roller 21; the loading roller 21 is laterally disposed above the workpiece platform 11, and the two support rollers 12 are symmetrically arranged about the central axis of the loading roller 21; the auxiliary positioning mechanism 3 includes: a base 31, the base 31 being placed on the two support rollers 12; the base 31 has The first plane 31a is used to abut against the test workpiece 100. The first plane 31a is perpendicular to the plane formed by the axes of the two support rollers 12, and the projection line of the first plane 31a on the plane formed by the axes of the two support rollers 12 is perpendicular to the two support rollers 12. The bottom of the base 31 is provided with a first positioning groove 311. When the base 31 is placed on the support rollers 12, the support rollers 12 are inserted into the first positioning groove 311. The top of the base 31 is provided with a second positioning groove 312. The second positioning groove 312 is located directly below the loading roller 21. When pressure is applied to the test workpiece 100, the loading roller 21 is driven to move downward into the second positioning groove 312.

[0040] The two support rollers 12 and the loading roller 21 are parallel to each other in spatial position. The support rollers 12 provide two reaction force fulcrums for the test workpiece 100, and the loading roller 21 applies a concentrated load to the middle of the test workpiece 100, forming a three-point bending loading system. The fracture toughness test of the test workpiece 100 is performed using the three-point bending loading principle. Before the test, a pre-cut notch is made on the test workpiece 100. When the loading roller 21 applies a concentrated load, it induces crack propagation at the notch. The fracture toughness test is mainly used to evaluate the material's ability to resist crack propagation, that is, the mechanical properties of the material to resist fracture when defects or cracks are present.

[0041] Both the support roller 12 and the loading roller 21 can be made of high-hardness, high-wear-resistant materials, including but not limited to alloy steel, cast iron or tungsten carbide composite materials. Their shape can usually be designed as a cylinder to ensure uniform distribution of contact stress.

[0042] The first positioning groove 311 adopts a semi-enclosed design with the groove opening facing downwards. Its shape is adapted to the support roller 12, and its cross-sectional shape can be designed as semi-circular, semi-elliptical, or semi-polygonal, etc. When the base 31 is placed on the support roller 12, the support roller 12 is accommodated within the first positioning groove 311 to restrict the horizontal degree of freedom of the base 31, so that the projection line of the first plane 31a always remains perpendicular to the support roller 12. When the test workpiece 100 is placed on the support roller 12 and abuts against the first plane 31a of the base 31, it can ensure that the test workpiece 100 maintains an orthogonal relationship with the axis of the three rollers (e.g., ...). Figure 6As shown in the figure, this solves the problems of span variation and additional bending moment caused by the pose deviation of the test workpiece 100 in traditional methods, and satisfies the geometric constraints of fracture toughness testing. Both the base 31 and the test workpiece 100 can be designed as cuboids, but this embodiment does not specifically limit their shapes.

[0043] The second positioning groove 312 adopts a semi-enclosed design with the groove opening facing upward. It works in conjunction with the loading roller 21 to constrain the position of the loading roller 21. Its cross-sectional shape includes, but is not limited to, a semi-circular shape, a semi-elliptical shape, or a rectangle.

[0044] It should be noted that the loading component 2 also includes a lifting device to realize the lifting and lowering of the loading roller 21. This lifting device includes, but is not limited to, an electric servo lift or a hydraulic servo lift.

[0045] The specific process of fracture toughness testing is as follows: A pre-cut notch is made at the bottom of the test workpiece 100. The test workpiece 100 is placed with the notch facing down on two support rollers 12, so that one side of the test workpiece 100 abuts against the first plane 31a of the base 31. The test workpiece 100 is moved to adjust its position so that the notch is directly below the loading roller 21. The loading roller 21 is driven by the lifting device to apply a load to the test workpiece 100, thereby conducting a fracture toughness test on the material.

[0046] The material fracture toughness testing device provided in this embodiment of the utility model constrains the spatial orientation of the two support rollers 12 and the loading roller 21 by setting a first positioning groove and a second positioning groove on the base 31 structure, ensuring that the axes of the three rollers are parallel. At the same time, when the test workpiece 100 is placed on the support roller 12 and abuts against the first plane 31a of the base 31, it can ensure that the axis of the test workpiece 100 is orthogonal to the axis of the three rollers, thereby effectively solving the problem of span change and additional bending moment caused by the orientation deviation of the test workpiece 100 in the traditional method, and satisfying the spatial geometric constraint conditions of fracture toughness testing.

[0047] Continue reading Figures 2-5 In some embodiments, the auxiliary positioning mechanism 3 may further include: two moving components 32; each moving component 32 includes: a slider 321 and a connecting block 322; the slider 321 is slidably disposed on the base 31 along a first direction x; the two sliders 321 are symmetrically arranged about the central axis of the loading roller 21; the connecting block 322 is disposed below the base 31, the connecting block 322 is connected to the bottom of the slider 321 and moves with the slider 321; the bottom of the connecting block 322 is provided with a first positioning groove 311.

[0048] Specifically, the base 31 includes a sliding platform, and the connecting block 322 and the sliding member 321 are connected as a whole to form a U-shaped structure. The opening of the U-shaped structure faces the sliding platform. An inverted first groove is provided on the top of the sliding member 321, which matches the top contour of the sliding platform. The first groove is inverted and rests on the sliding platform, thereby forming a sliding pair structure between the sliding member 321 and the sliding platform. By manually controlling the sliding member 321 to slide along the sliding platform, the first positioning groove 311 at the bottom of the connecting block 322 is moved. When the sliding member 321 moves to the target position, it can be locked onto the sliding platform by the cooperation of bolts and threaded holes. By adjusting the position of the first positioning groove 311 by the moving component 32, precise alignment and reliable engagement with the support roller 12 can be achieved.

[0049] It should be noted that, in order to eliminate the interference of the sliding member 321 on the contact between the test workpiece 100 and the base 31, it can be installed on the back of the base 31; the first direction x refers to the direction perpendicular to the axis of the support roller 12.

[0050] In some embodiments, a scale value 4 is provided on the first plane 31a along the first direction x, and a first pointer 5 is provided on the top of the slider 321. The first pointer 5 points to the scale value 4 to display the moving distance of the first positioning groove 311.

[0051] During adjustment, the projection point of the loading roller 21 on the scale line is first used as the "0" scale reference. Before installing the base 31, the position of the first positioning groove 311 can be pre-calibrated and locked. The specific operation process is as follows: first, measure the span between the two support rollers 12 to determine the adjustment amount of the first positioning groove 311, then adjust the first pointer 5 to the corresponding scale through the moving component 32, then fix the sliding member 321 to the sliding platform with bolts, and finally insert the two first positioning grooves 311 at the bottom of the base 31 with the two support rollers 12 to complete the positioning.

[0052] In some embodiments, the auxiliary positioning mechanism 3 may further include: a first positioning member 33, the first positioning member 33 having a first slot 331 at its bottom and a second positioning groove 312 at its top; and a protrusion 313 at the top of the base 31, the protrusion 313 being located directly below the loading roller 21, the protrusion 313 engaging with the first slot 331. The first positioning member 33 is designed as a detachable H-shaped structure for easy replacement and to prevent damage to the second positioning groove 312 caused by the pressure of the loading roller 21.

[0053] In fracture toughness testing, relying solely on visual adjustment makes it difficult to ensure that the pre-cut notch of the test workpiece 100 is precisely aligned with the center line of the loading roller 21, which will still introduce positioning errors. Furthermore, in some embodiments, the auxiliary positioning mechanism 3 may further include: a second positioning element 34 and a fastener 35; the second positioning element 34 is slidably disposed on the first plane 31a along the first direction x; one side of the second positioning element 34 along the first direction x is the second plane 341, which is perpendicular to the first plane 31a, forming a right angle. When the test workpiece 100 is placed on the support roller 12, the test workpiece 100 abuts against the first plane 31a and the second plane 341 respectively; when the second positioning element 34 abuts against the test workpiece 100, the second positioning element 34 is locked onto the base 31 by the fastener 35.

[0054] Specifically, the base 31 has a sliding groove 314 on its first plane 31a along the first direction x. The second positioning member 34 includes a slider and an abutment block. The slider is slidably connected to the sliding groove 314. The sliding adjustment of the second positioning member 34 is realized through the sliding groove-slider cooperation mechanism. The abutment block is fixedly connected to the slider and moves synchronously with it. The side of the abutment block forms the second plane 341. Through the right-angle positioning structure formed by the first plane 31a and the second plane 341, bidirectional precise calibration of the test workpiece 100 is realized.

[0055] This embodiment of the invention constructs a right-angle positioning structure to achieve bidirectional calibration of the test workpiece 100, effectively eliminating centering deviation, ensuring accurate load application position, and improving the accuracy and reliability of test data.

[0056] In some embodiments, a scale value 4 is provided on the first plane 31a along the first direction x; a second pointer 6 is provided on the second plane 341, and the second pointer 6 points to the scale value 4 to display the moving distance of the second positioning member 34.

[0057] Specifically, the second pointer 6 can be a right-angled triangular block, which is connected to the top of the abutment block to form an integral structure. One right-angled side of the right-angled triangular block is coplanar with the second plane 341, and the tip of the right-angled triangular block points to the scale value 4. The projection point of the loading roller 21 on the scale line is used as the "0" scale reference.

[0058] Before testing, the span between one side of the test workpiece 100 and the cut is measured in advance; the second positioning member 34 is moved so that the second pointer 6 points to the scale value 4 corresponding to the span, and the second positioning member 34 is locked on the base 31 by the fastener 35; the test workpiece 100 is placed on the two support rollers 12 so that one side of the test workpiece 100 abuts against the first plane 31a of the base 31, and the other side of the test workpiece 100 abuts against the second plane 341 of the second positioning member 34, thereby completing the positioning.

[0059] In some embodiments, see Figure 2 The support assembly 1 also includes two support seats 13, which are slidably disposed on the upper surface of the workpiece platform 11; the top of the support seat 13 is provided with a receiving groove 131, and the support roller 12 is placed in the receiving groove 131.

[0060] Specifically, the workpiece platform 11 can be equipped with guide rails on its upper surface, and the support base 13 can be equipped with sliders or rollers at its bottom. The sliding function is achieved through the cooperation of slider-guide rail or roller-guide rail, or the workpiece platform 11 itself can be used as the guide rail. When the workpiece platform 11 itself is used as the guide rail, the bottom of the support base 13 is provided with an inverted second groove that matches the top contour of the workpiece platform 11, thus forming a sliding pair structure. The support base 13 can be manually slid along the workpiece platform 11, thereby adjusting the span between the two support rollers 12. When the support base 13 moves to the target position, it can be locked onto the workpiece platform 11 by the cooperation of bolts and threaded holes. It should be noted that the top of the support base 13 can be provided with a boss structure, and a receiving groove 131 is provided on the boss structure to provide deformation space for testing the fracture of the workpiece 100.

[0061] In some embodiments, see Figure 2 The support assembly 1 also includes: a fixing seat 14; the fixing seat 14 is provided with a second slot 141; the fixing seat 14 is located below the workpiece platform 11; the bottom of the workpiece platform 11 has a downwardly extending fixing part 111, which is engaged with the second slot 141.

[0062] The fixed base 14 adopts a cylindrical structure design, and the workpiece platform 11 is assembled by inserting its fixing part 111 into the second slot 141 of the fixed base 14. This structure not only provides stable fixed support for the workpiece platform 11, but also allows the operator to precisely adjust the relative positional relationship between the support roller 12 and the loading roller 21 by manually rotating the workpiece platform 11.

[0063] Using the aforementioned material fracture toughness testing device, the first method for testing material fracture toughness is as follows:

[0064] 1) Place the test workpiece 100 horizontally on the two support rollers 12, and make the test workpiece 100 abut against the first plane 31a of the base 31;

[0065] 2) Move the test workpiece 100 so that the projection of the cut on the test workpiece 100 is on the central axis of the loading roller 21;

[0066] 3) Start the loading roller 21 to apply a load to the test workpiece 100.

[0067] In addition, the second method for testing the fracture toughness of materials is as follows:

[0068] 1) Pre-measure the span between one side of the test workpiece 100 and the cut;

[0069] 2) Move the second positioning member 34 so that the second pointer 6 indicates the scale value 4 corresponding to the span, and lock the second positioning member 34 onto the base 31 by the fastener 35;

[0070] 3) Place the test workpiece 100 on the two support rollers 12, so that one side of the test workpiece 100 abuts against the first plane 31a of the base 31, and the other side of the test workpiece 100 abuts against the second plane 341 of the second positioning member 34.

[0071] 4) Start the loading roller 21 to apply load to the test workpiece 100.

[0072] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A material fracture toughness testing device, characterized in that, include: A support assembly includes: a workpiece platform and two support rollers; the support rollers are laterally disposed on the upper surface of the workpiece platform, and the two support rollers are arranged in parallel; the support rollers are used to support the test workpiece. The loading assembly includes: a liftable loading roller; the loading roller is laterally positioned above the workpiece platform, and two support rollers are symmetrically arranged about the central axis of the loading roller; An auxiliary positioning mechanism includes: a base placed on two support rollers; the base having a first plane for contacting the test workpiece; the first plane being perpendicular to the plane formed by the axes of the two support rollers, and the projection line of the first plane on the plane formed by the axes of the two support rollers being perpendicular to the two support rollers; a first positioning groove at the bottom of the base, wherein the support rollers are inserted into the first positioning groove when the base is placed on the support rollers; and a second positioning groove at the top of the base, located directly below the loading roller, wherein the loading roller can engage with the second positioning groove when the loading roller is driven to move downward.

2. The material fracture toughness testing device according to claim 1, characterized in that, The auxiliary positioning mechanism further includes: two moving components; the moving components include: A sliding member is slidably disposed on the base along a first direction; the two sliding members are symmetrically arranged about the central axis of the loading roller. A connecting block is disposed below the base. The connecting block is connected to the bottom of the slider and moves with the slider. The bottom of the connecting block is provided with the first positioning groove.

3. The material fracture toughness testing device according to claim 2, characterized in that, The first plane has a scale value along the first direction, and the top of the slider has a first pointer. The first pointer points to the scale value to display the moving distance of the first positioning groove.

4. The material fracture toughness testing device according to claim 1, characterized in that, The auxiliary positioning mechanism also includes: The first positioning component has a first slot at its bottom and a second positioning groove at its top; the top of the base has a protrusion located directly below the loading roller, and the protrusion engages with the first slot.

5. The material fracture toughness testing device according to claim 1, characterized in that, The auxiliary positioning mechanism also includes: The second positioning component is slidably disposed on the first plane along the first direction; one side of the second positioning component along the first direction is the second plane, and the second plane is perpendicular to the first plane to form a right angle. When the test workpiece is placed on the support roller and the cut at the bottom of the test workpiece is located directly below the loading roller, the first plane and the second plane respectively abut against the test workpiece. When the first plane and the second plane respectively abut against the test workpiece, the second positioning member is locked onto the base by the fastener.

6. The material fracture toughness testing device according to claim 5, characterized in that, The first plane has a scale value along a first direction; the second plane has a second pointer, which points to the scale value to display the moving distance of the second positioning element.

7. The material fracture toughness testing device according to claim 1, characterized in that, The support components also include: Two support seats are slidably disposed on the upper surface of the workpiece platform; the top of the support seats is provided with a receiving groove, and the support roller is placed in the corresponding receiving groove.

8. The material fracture toughness testing device according to claim 7, characterized in that, The support components also include: A fixing base is provided with a slot; the fixing base is located below the workpiece platform; the bottom of the workpiece platform has a downwardly extending fixing part, which is inserted into the slot.

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