Rock compression-tensile conversion device

Abstract

The utility model discloses a rock compression resistance-tensile conversion device, which belongs to the technical field of stress measurement devices and comprises an end bearing plate and a middle bearing plate, and the end bearing plate comprises a top bearing plate and a bottom bearing plate. The middle bearing plate comprises a first middle bearing plate and a second middle bearing plate which are sequentially arranged between the top bearing plate and the bottom bearing plate; the opposite side walls of the top bearing plate and the bottom bearing plate are each sleeved with a plurality of bearing columns penetrating through the first middle bearing plate or the second middle bearing plate, a bearing sample containing area is formed between the first middle bearing plate and the second middle bearing plate, and a first extension area is formed between the top bearing plate and the first middle bearing plate. And a second extension area is formed between the bottom bearing plate and the second middle bearing plate. According to the conversion device disclosed by the utility model, the pressure bearing plate and the pressure bearing column are connected, so that the technical problems that a conversion device in the prior art needs to process a rock to be tested into a sample with a specific size and the adaptability to the sample is relatively low are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of stress measurement devices, and relates to a rock compression-tension conversion device. Background Art

[0002] The tensile strength of rock is one of its important mechanical indexes. Since the 21st century, a rock direct tensile testing machine has been used to apply symmetric tensile stresses along the axial direction on the upper and lower end faces of a rock specimen to measure the tensile strength of the rock, gradually replacing the Brazilian splitting method as a new means for testing the tensile strength of rock. However, due to the high cost and single function of the rock direct tensile testing machine, it is difficult to popularize the rock direct tensile test. Some scholars have proposed a "compression-tension" conversion device, which can convert the compressive stress borne by the rock into tensile stress, and the rock direct tensile test can be completed by using a rock compression testing machine.

[0003] However, the existing conversion devices are often made by integral casting. On the one hand, the mold is relatively heavy and needs to be remade if part of it is damaged, resulting in a high cost. On the other hand, the rock to be tested needs to be processed into a specimen with specific dimensions, and the adaptability to the specimen is relatively low. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a rock compression-tension conversion device, which solves the technical problem that in the prior art, the conversion device needs to process the rock to be tested into a specimen with specific dimensions, and the adaptability to the specimen is relatively low.

[0005] The technical solution adopted by the utility model is that the rock compression-tension conversion device includes end bearing plates and a middle bearing plate. The end bearing plates include a top bearing plate and a bottom bearing plate. The middle bearing plate includes a first middle bearing plate and a second middle bearing plate which are arranged between the top bearing plate and the bottom bearing plate in sequence along the vertical direction. A plurality of pressure-bearing columns passing through the first middle bearing plate and fixedly connected to the second middle bearing plate are sleeved on the top bearing plate, and a plurality of pressure-bearing columns passing through the second middle bearing plate and fixedly connected to the first middle bearing plate are sleeved on the bottom bearing plate. A bearing specimen placement area is formed between the first middle bearing plate and the second middle bearing plate, a first extension area is formed between the top bearing plate and the first middle bearing plate, and a second extension area is formed between the bottom bearing plate and the second middle bearing plate.

[0006] The characteristics of the utility model also lie in that:

[0007] A plurality of through holes and second grooves are uniformly arranged at intervals along the axis on the first middle bearing plate and the second middle bearing plate, and the outer walls of the plurality of pressure-bearing columns are in close contact with the through holes.

[0008] A plurality of first grooves coaxial with the pressure-bearing columns are arranged on both the top bearing plate and the bottom bearing plate, and the ends of the pressure-bearing columns are matched with the first grooves.

[0009] The number of pressure-bearing columns is six, the number of through holes and second grooves on the first middle bearing plate and the second middle bearing plate is three each, and the number of first grooves on the top bearing plate and the bottom bearing plate is six each;

[0010] Wherein, one end of the pressure-bearing column is sleeved with the first groove, the other end of the pressure-bearing column is fixedly connected with the second groove, the second groove is provided with internal threads, and one end of the pressure-bearing column is provided with external threads.

[0011] The top bearing plate, the bottom bearing plate, the first middle bearing plate and the second middle bearing plate are all made of regular hexagonal plates.

[0012] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0013] The rock compression-tension conversion device disclosed by the present utility model uses cast iron to make the mold, changes the original integrated mold into the connection between components, optimizes the production and application range of the mold on the basis of ensuring the stiffness and functionality of the mold; its structure is simple and does not need to be replaced as a whole after damage, only some components need to be replaced, saving the mold production cost; and the rock compression-tension conversion device disclosed by the present utility model eliminates the requirements for the specimen size in the use of the previous mold, and specimens of any shape and size can be selected, and the specimen adaptability is relatively high. Description of the Drawings

[0014] Figure 1 is a schematic structural diagram of the rock compression-tension conversion device of the present utility model;

[0015] Figure 2 is a schematic structural diagram of the middle bearing plate in the rock compression-tension conversion device of the present utility model;

[0016] Figure 3 is Figure 2 the top view of

[0017] Figure 4 is a schematic structural diagram of the end bearing plate in the rock compression-tension conversion device of the present utility model;

[0018] Figure 5 is Figure 4 the top view of

[0019] Figure 6 is a schematic structural diagram of the pressure-bearing column in the rock compression-tension conversion device of the present utility model;

[0020] Figure 7 is a schematic structural diagram of the installation of the pressure-bearing column and the second middle bearing plate in the rock compression-tension conversion device of the present utility model;

[0021] Figure 8It is a schematic structural diagram of the installation of the pressure-bearing column and the middle pressure-bearing plate in the rock compression-tension conversion device of the present utility model.

[0022] In the figure, 1. End pressure-bearing plate, 101. Top pressure-bearing plate, 102. Bottom pressure-bearing plate, 103. First groove, 2. Middle pressure-bearing plate, 201. First middle pressure-bearing plate, 202. Second middle pressure-bearing plate, 203. Through hole, 204. Second groove, 3. Pressure-bearing column, 4. Threaded section. Specific implementation mode

[0023] The present utility model will be further explained and described below in conjunction with the accompanying drawings and specific implementation modes.

[0024] Embodiment 1

[0025] As Figure 1-8 shown, the rock compression-tension conversion device provided by the present utility model includes an end pressure-bearing plate 1 and a middle pressure-bearing plate 2. The end pressure-bearing plate 1 includes a top pressure-bearing plate 101 and a bottom pressure-bearing plate 102. The middle pressure-bearing plate 2 includes a first middle pressure-bearing plate 201 and a second middle pressure-bearing plate 202 which are arranged between the top pressure-bearing plate 101 and the bottom pressure-bearing plate 102 and are arranged in sequence along the vertical direction. A plurality of pressure-bearing columns 3 which penetrate through the first middle pressure-bearing plate 201 and are fixedly connected to the second middle pressure-bearing plate 202 are sleeved on the side wall of the top pressure-bearing plate 101 facing the bottom pressure-bearing plate 102. A plurality of pressure-bearing columns 3 which penetrate through the second middle pressure-bearing plate 202 and are fixedly connected to the first middle pressure-bearing plate 201 are sleeved on the side wall of the bottom pressure-bearing plate 102 facing the top pressure-bearing plate 101. A bearing specimen placement area is formed between the first middle pressure-bearing plate 201 and the second middle pressure-bearing plate 202. A first extension area is formed between the top pressure-bearing plate 101 and the first middle pressure-bearing plate 201. A second extension area is formed between the bottom pressure-bearing plate 102 and the second middle pressure-bearing plate 202.

[0026] In the rock compression-tension conversion device of the present utility model, the top pressure-bearing plate 101, the bottom pressure-bearing plate 102, the first middle pressure-bearing plate 201, the second middle pressure-bearing plate 202 and the pressure-bearing column 3 are made of cast iron plates.

[0027] During the test, the bottom pressure-bearing plate 102 together with the pressure-bearing column 3 moves upward under the compressive stress applied by the lower end of the testing machine. The top pressure-bearing plate 101 together with the pressure-bearing column 3 moves downward under the compressive stress applied by the upper end of the testing machine. The specimen bears the tensile stress caused by the relative movement of the top pressure-bearing plate 101 and the bottom pressure-bearing plate 102, and the conversion of compressive stress to tensile stress can be realized. The first middle pressure-bearing plate 201 and the second middle pressure-bearing plate 202 are used to fix the pressure-bearing column 3 and bear the specimen.

[0028] Embodiment 2

[0029] On the basis of Embodiment 1, a number of through holes 203 and second grooves 204 are arranged at equal intervals along the axis on the first middle bearing plate 201 and the second middle bearing plate 202, and the outer walls of a number of bearing columns 3 are in close contact with the through holes 203.

[0030] Furthermore, both the first middle bearing plate 201 and the second middle bearing plate 202 are regular hexagons with a thickness of 15 mm and a side length of 100 mm. The through holes 203 and the second grooves 204 are both opened at a distance of 20 mm from the vertices. The diameters of the through holes 203 and the second grooves 204 are both 30 mm. Threads are provided on the inner wall of the second groove 204, and the end of the bearing column 3 is provided with a threaded section 4, and the threaded section 4 is matched with the second groove 204.

[0031] Furthermore, a number of first grooves 103 coaxial with the bearing columns 3 are provided on the side walls of the top bearing plate 101 and the bottom bearing plate 102. The inner walls of the first grooves 103 are smooth, and the ends of the bearing columns 3 can be inserted into the first grooves 103.

[0032] The top bearing plate 101 and the bottom bearing plate 102 ensure integrity and stability on the one hand, and on the other hand, are used to evenly transfer the load applied by the testing machine to the top of the bearing columns 3 to avoid eccentricity and stress concentration.

[0033] Embodiment 3

[0034] On the basis of Embodiment 1, both the top bearing plate 101 and the bottom bearing plate 102 are regular hexagons with a thickness of 15 mm and a side length of 100 mm. The first groove 103 is opened at a distance of 20 mm from the vertex. The diameter of the first groove 103 is 30 mm, and the depth of the first groove 103 is 5 mm.

[0035] Furthermore, the number of bearing columns 3 is six. The number of through holes 203 on the first middle bearing plate 201 and the second middle bearing plate 202 is three each. The number of first grooves 103 on the top bearing plate 101 and the bottom bearing plate 102 is six each, which is convenient for installing the bearing columns 3.

[0036] Among them, one end of the bearing column 3 is sleeved with the first groove 103, the other end of the bearing column 3 is fixedly connected with the second groove 204. Internal threads are provided in the second groove 204, and external threads are provided at one end of the bearing column 3, that is, the threaded section 4 as shown in Figure 6 . The six bearing columns 3 are arranged in a cross pattern. Ensure that the bearing columns 3 can be placed into the first grooves 103 to form a whole.

[0037] The six bearing columns 3 are used to transfer the load. The height of the bearing columns 3 needs to be greater than the height of the specimen to be tested. The diameter of the bearing columns 3 is equal to the diameter of the holes on the first middle bearing plate 201 and the second middle bearing plate 202. The bearing columns 3 are cylinders with a diameter of 30 mm and a height of 150 mm, and the total height of the threaded section 4 provided at one end of the cylinder is 10 mm.

[0038] The specific usage method of the present utility model specifically includes the following steps:

[0039] Step 1: Use a grinding machine to polish the upper and lower surfaces of the specimen to be tested until smooth, and the non-parallel error of the two end faces of the specimen is less than 0.05 mm;

[0040] Step 2: Apply vaseline oil on the side wall surfaces of the six bearing columns 3 to reduce the friction between them and the hole walls of the through holes 203;

[0041] Step 3: Screw the six bearing columns 3 into the second grooves 204 of the first middle bearing plate 201 and the second middle bearing plate 202 at intervals, and three bearing columns are installed on each of the first middle bearing plate 201 and the second middle bearing plate 202;

[0042] Step 4: Apply epoxy resin glue to one end of the specimen to be tested and fix it at the center of the first middle bearing plate 201; apply epoxy resin glue to the other end of the specimen to be tested, rotate the second middle bearing plate 202, insert the bearing columns 3 into the through holes 203 of the first middle bearing plate 201, and correspondingly, insert the three bearing columns 3 on the first middle bearing plate 201 into the through holes 203 of the second middle bearing plate 202;

[0043] Step 5: Wind cotton threads around the two ends of the first middle bearing plate 201 and the second middle bearing plate 202 to make the two ends of the specimen to be tested in close contact with the first middle bearing plate 201 and the second middle bearing plate 202. After the epoxy resin glue dries, remove the cotton threads.

[0044] Step 6: Install the top bearing plate 101 and the bottom bearing plate 102 at the ends of the bearing columns 3 to obtain the rock compression-tension conversion device of the present utility model, and place the rock compression-tension conversion device of the present utility model together with the specimen on the testing machine to start the corresponding test.

Claims

1. Rock compressive-tensile conversion device, characterized in that, It includes an end bearing plate (1) and a middle bearing plate (2). The end bearing plate (1) includes a top bearing plate (101) and a bottom bearing plate (102). The middle bearing plate (2) includes a first middle bearing plate (201) and a second middle bearing plate (202) which are arranged between the top bearing plate (101) and the bottom bearing plate (102) and are arranged in sequence along the vertical direction. A number of bearing columns (3) that penetrate through the first middle bearing plate (201) and are fixedly connected to the second middle bearing plate (202) are sleeved on the top bearing plate (101). A number of bearing columns (3) that penetrate through the second middle bearing plate (202) and are fixedly connected to the first middle bearing plate (201) are sleeved on the bottom bearing plate (102). A bearing specimen placement area is formed between the first middle bearing plate (201) and the second middle bearing plate (202). A first extension area is formed between the top bearing plate (101) and the first middle bearing plate (201). A second extension area is formed between the bottom bearing plate (102) and the second middle bearing plate (202).

2. The rock compressive-tensile conversion device according to claim 1, wherein A number of through holes (203) and second grooves (204) are evenly arranged at intervals along the axis on the first middle bearing plate (201) and the second middle bearing plate (202). The outer walls of the number of bearing columns (3) are in close contact with the through holes (203).

3. The rock compressive-tensile conversion device according to claim 2, characterized in that, A number of first grooves (103) coaxial with the bearing columns (3) are provided on both the top bearing plate (101) and the bottom bearing plate (102). The ends of the bearing columns (3) are matched with the first grooves (103).

4. The rock compressive-tensile conversion device according to claim 3, characterized in that The number of the bearing columns (3) is six. The number of the through holes (203) and the second grooves (204) on the first middle bearing plate (201) and the second middle bearing plate (202) is three each. The number of the first grooves (103) on the top bearing plate (101) and the bottom bearing plate (102) is six each. Among them, one end of the bearing column (3) is sleeved with the first groove (103), the other end of the bearing column (3) is fixedly connected to the second groove (204). Internal threads are provided in the second groove (204). External threads are provided at one end of the bearing column (3).

5. The rock compressive-tensile conversion device according to any one of claims 1-4, characterized in that, The top bearing plate (101), the bottom bearing plate (102), the first middle bearing plate (201) and the second middle bearing plate (202) all adopt regular hexagonal plates.

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