Tensile test rock sample preparation mold
By designing a tensile test rock sample preparation mold containing symmetrical upper and lower cracks, the problem of the shape and size limitation of the specimen in the traditional tensile test method is solved, and a rock tensile test with high accuracy and repeatability is achieved.
Patent Information
- Application Number
- CN202421601061.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-08
- Publication Date
- 2025-05-23
- Estimated Expiration
- 2034-07-08
AI Technical Summary
The traditional direct tensile testing method is limited by the shape and size of the specimen, resulting in poor inaccuracy and repeatability of the test results. The indirect testing method has problems such as uneven stress distribution and strict geometric shape requirements of the specimen.
A tensile test rock sample preparation mold is designed, including a mold box and a limit frame. The mold box is equipped with a first partition and a second partition. By forming symmetrical upper and lower cracks, the mold can directly conduct tensile test of the rock sample on the pressure test bench.
The mold can directly prepare symmetrical rock samples containing two upper cracks and two lower cracks, overcome the clamping difficulties of direct tensile tests and the stress concentration problem in indirect tests, simplify the test operation, and improve the accuracy and repeatability of the test results.
Smart Images
Figure CN222895972U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of rock mechanics testing, in particular to a rock sample preparation die for a tensile test. Background Art
[0002] When studying the mechanical properties of rocks, tensile testing is one of the more commonly used test methods, which can show in detail the behavior of rocks under tensile loads, including their strength, deformation characteristics, and failure modes.
[0003] Traditional tensile tests mainly include indirect tests and direct tests. Indirect test methods (such as the Brazilian splitting test and the three-point bending test) have a wide range of applications and can simulate the stress conditions of rocks in actual engineering projects. However, indirect test methods also have some limitations, such as the uneven distribution of stress during the test and the requirements for the geometric shape of the specimen, which limits the scope of application. Direct tests clamp the two ends of the specimen and then apply a tensile load until it fails. However, traditional direct tensile test methods also have some challenges. For example, they are limited by the shape and size of the specimen, which may lead to inaccurate test results and poor repeatability. Utility Model Content
[0004] The utility model aims to provide a rock sample preparation mold for a tensile test. The rock sample prepared by the mold can be directly used for the tensile test of the rock sample on a pressure test bench, thereby overcoming the difficulty of clamping test in direct tensile test and the influence of stress concentration at the layering strip in indirect test on the test result, and simplifying the operation during the test.
[0005] The purpose of this utility model is achieved through the following technical solutions:
[0006] A tensile test rock sample preparation mold, including a mold box, the mold box includes a bottom plate, the top surface of the bottom plate is provided with a left plate, a right plate, a front plate and a rear plate, the left plate, the front plate, the right plate and the rear plate are connected in sequence and surround the bottom plate to form a rectangular cavity with a top opening, the rectangular cavity includes two opposite left and right side inner walls and two opposite front and rear side inner walls, two first partitions and two second partitions are arranged in the mold box, the first partition and the second partition are both arranged parallel to the front and rear side inner walls, the bottom end of the first partition is connected to the bottom plate, one side end of the first partition is connected to the left plate, the two first partitions are symmetrically arranged along the center line of the left and right side inner walls, the bottom end of the second partition is connected to the bottom plate, one side end of the second partition is connected to the right plate, the two second partitions are symmetrically arranged along the center line of the left and right side inner walls, the width of the first partition is greater than half of the width of the front and rear side inner walls, and the width of the second partition is the same as the width of the first partition.
[0007] Specifically, a rectangular boss is arranged at the center of the top surface of the bottom plate, the lower parts of the inner walls of the left plate, the right plate, the front plate and the rear plate are respectively abutted against the four side surfaces of the boss, the top surface of the boss forms the bottom surface of the rectangular cavity, the inner walls of the left plate and the right plate are provided with slots A and slots B, the two side ends of the front plate are respectively arranged in the two slots A, the two side ends of the rear plate are respectively arranged in the two slots B, and a limit frame is also included, and the limit frame is sleeved on the outside of the mold box.
[0008] Furthermore, the limit frame includes two inclined plates and two straight plates, and the limit frame is a rectangular frame structure. The two inclined plates are arranged opposite to each other, and the two straight plates are arranged opposite to each other. The outer walls of the left plate and the right plate are fixedly provided with wedge blocks, and the wedge blocks are adapted to the inclined plates so that when the limit frame moves toward the bottom plate, the left plate and the right plate are pressed toward the boss direction.
[0009] Furthermore, it also includes a tightening screw, one end of which is fixedly connected to the base plate, and the other end of which passes through the straight plate and is threadedly connected to a tightening nut.
[0010] Specifically, two first slots A are provided on the left side panel, two first slots B are provided on the bottom panel, one side end of the first partition is inserted into the first slot A, and the bottom end of the first partition is inserted into the first slot B, two second slots A are provided on the right side panel, two second slots B are provided on the bottom panel, one side end of the second partition is inserted into the second slot A, and the bottom end of the second partition is inserted into the second slot B.
[0011] Furthermore, the first partition plate and the second partition plate are both provided with lifting holes.
[0012] The beneficial effects of the utility model are:
[0013] The tensile test rock sample preparation mold includes a mold box, which is surrounded by a bottom plate, a left plate, a right plate, a front plate and a rear plate to form a rectangular cavity. Two first partitions and two second partitions are arranged in the mold box. The first partition and the second partition are parallel to the front and rear inner walls of the rectangular cavity. Along the center line of the left and right inner walls of the rectangular cavity, the two first partitions are symmetrical to each other, and the two second partitions are symmetrical to each other. The bottom ends of the first partition and the second partition are both connected to the bottom plate, the side ends of the first partition are connected to the left plate, and the side ends of the second partition are connected to the right plate. The widths of the first partition and the second partition are the same and are greater than half of the width of the left and right inner walls of the rectangular cavity. The tensile test rock sample preparation mold can directly prepare a rock sample containing two upper cracks and two lower cracks after casting, curing and demoulding. The entire rock sample is a symmetrical model, and the tensile test of the rock sample can be directly carried out on the pressure test bench, which overcomes the difficulty of clamping test in direct tensile test and the influence of stress concentration at the layering strip in indirect test on the test results, and simplifies the operation during the test. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 A schematic diagram of the structure of a rock sample prepared by a rock sample preparation mold for a tensile test according to the utility model;
[0015] Figure 2 for Figure 1 The schematic diagram of the principle of the rock specimen when a tensile test is carried out by applying pressure;
[0016] Figure 3 This is a schematic diagram of the overall structure of a mold for preparing a rock sample for a tensile test according to the utility model;
[0017] Figure 4 for Figure 3 Schematic diagram of the explosion structure;
[0018] In the figure, 1-rock sample, 2-upper crack, 3-lower crack, 4-tension part, 5-pad, 6-bottom plate, 7-left plate, 8-right plate, 9-front plate, 10-rear plate, 11-first partition plate, 12-second partition plate, 13-boss, 14-slot A, 15-slot B, 16-first slot A, 17-first slot B, 18-second slot A, 19-second slot B, 20-inclined plate, 21-straight plate, 22-wedge block, 23-tensioning screw, 24-tensioning nut. DETAILED DESCRIPTION
[0019] The technical solution of the present utility model is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present utility model is not limited to the following.
[0020] like Figure 3 , Figure 4As shown, a tensile test rock specimen preparation mold includes a mold box, the mold box includes a bottom plate 6, the top surface of the bottom plate 6 is provided with a left plate 7, a right plate 8, a front plate 9 and a rear plate 10, the left plate 7, the front plate 9, the right plate 8 and the rear plate 10 are sequentially connected and surround the bottom plate 6 to form a rectangular cavity with a top opening, the rectangular cavity includes two opposite left and right side inner walls (the left side plate 7 and the right side plate 8 are located in the side wall portion of the rectangular cavity) and two opposite front and rear side inner walls (the front plate 9 and the rear plate 10 are located in the side wall portion of the rectangular cavity). On this basis, two first partitions 11 and two second partitions 12 are also arranged in the mold box. The first partition 11 and the second partition 12 are arranged parallel to the front and rear inner walls; the bottom end of the first partition 11 is connected to the bottom plate 6, and one side end of the first partition 11 is connected to the left side plate 7. The two first partitions 11 are arranged symmetrically along the center line of the left and right inner walls; the bottom end of the second partition 12 is connected to the bottom plate 6, and one side end of the second partition 12 is connected to the right side plate 8. The two second partitions 12 are also arranged symmetrically along the center line of the left and right inner walls. The width of the first partition 11 is greater than half of the width of the front and rear inner walls, and the width of the second partition 12 is the same as the width of the first partition 11.
[0021] The tensile test rock specimen preparation mold can be directly prepared after casting, curing and demoulding. Figure 1 In the rock sample 1 shown, two upper cracks 2 parallel to the center line of the sample are formed at the positions of the two first partitions 11, and two lower cracks 3 parallel to the center line of the sample are formed at the positions of the two second partitions 12. Since the widths of the first partitions 11 and the second partitions 12 are the same and greater than half of the width of the front and rear inner walls, the depths of the upper cracks 2 and the lower cracks 3 are the same and they are staggered, and a tension portion 4 is formed between the adjacent upper cracks 2 and lower cracks 3. Figure 2 In the manner shown, the prepared rock sample 1 is placed on the test bench, and pads 5 are installed at the two ends of the lower surface and the middle of the upper surface, so that when pressure is applied on the test bench, it can be converted into tension on the tension part 4, completing the tensile test of this part of the rock. Since the prepared rock sample 1 is a symmetrical model, although the pressure and tension are not on the same straight line during the test, there is no bending moment in the tension part 4 due to the symmetry of the sample, and the tension part 4 is only damaged by pure tension.
[0022] It can be seen that the rock sample 1 prepared by the tensile test rock sample preparation mold can be directly used for tensile testing of rock samples on the pressure test bench, which overcomes the difficulty of clamping test in direct tensile test and the influence of stress concentration at the pressure strip in indirect test on the test results, and simplifies the operation during the test.
[0023] When implementing, Figure 4As shown, a rectangular boss 13 is provided at the center of the top surface of the bottom plate 6, and the lower parts of the inner side walls of the left side plate 7, the right side plate 8, the front plate 9 and the rear plate 10 are respectively in contact with the four side surfaces of the boss 13, and the top surface of the boss 13 forms the bottom of the aforementioned rectangular cavity. Slots A14 and B15 are provided on the inner side walls of the left side plate 7 and the right side plate 8, and the two side ends of the front plate 9 are respectively provided in the two slots A14, and the two side ends of the rear plate 10 are respectively provided in the two slots B15. The above-mentioned left side plate 7, right side plate 8, front plate 9 and rear plate 10 are detachably connected to the bottom plate 6, and can be positioned by using the four sides of the boss 13, and can be quickly spliced by plugging; and after the splicing is completed, a limit frame is set on the outside of the mold box to tighten the front side plate 7 and the right side plate 8 inward to keep the mold box structurally stable during the pouring and curing process; after the pouring and curing are completed, the limit frame can be taken out, and the left side plate 7 and the right side plate 8 can be directly taken out to both sides, and then the front plate 9 and the rear plate 10 can be removed, and the demoulding process is extremely convenient.
[0024] In the specific implementation, in order to facilitate demoulding, the first partition 11 and the second partition 12 are also plugged in. Specifically: two first slots A16 are provided on the left side plate 7, and two first slots B17 are provided on the bottom plate. One side end of the first partition 11 is inserted into the first slot A16, and the bottom end of the first partition 11 is inserted into the first slot B17; two second slots A18 are provided on the right side plate 8, and two second slots B19 are provided on the bottom plate 6. One side end of the second partition 12 is inserted into the second slot A18, and the bottom end of the second partition 12 is inserted into the second slot B19. Furthermore, lifting holes are provided on the first partition 11 and the second partition 12 (the position of the slurry during pouring does not exceed the position of the lifting holes). After the curing is completed, the first partition 11 and the second partition 12 can be pulled out by holding the lifting holes to complete the demoulding of the sample.
[0025] Furthermore, the above-mentioned limit frame includes two inclined plates 20 and two straight plates 21. The limit frame is a rectangular frame structure, and the two inclined plates 20 are arranged opposite to each other, and the two straight plates 21 are arranged opposite to each other. Wedge blocks 22 are fixedly arranged on the outer wall of the left side plate 7 and the outer wall of the right side plate 8, and the wedge blocks 22 are adapted to the inclined plates 20. When the limit frame is installed downward, as the limit frame is pressed toward the bottom plate 6, the bottom ends of the left side plate 7 and the right side plate 8 can be pressed against the bottom plate 6, and the left side plate 7 and the right side plate 8 can also be pressed against the boss 13, reducing or preventing the slurry from leaking out from the bottom ends of the left side plate 7 and the right side plate 8 after pouring; and the front side plate 9 and the rear side plate 10 can be directly pressed against the bottom plate 6 by pressing down after the assembly is completed to reduce or prevent the slurry from leaking out. During the pressing process, the left side plate 7 presses the first partition plate 11 toward the end of the first slot B17, and the right side plate 8 presses the second partition plate 12 toward the end of the second slot B19, thereby maintaining the stability of the entire structure.
[0026] Furthermore, a tightening screw 23 is provided, one end of which is fixedly connected to the base plate 6, and the other end of the tightening screw 23 passes through the straight plate 21 and is threadedly connected to a tightening nut 24. When the limit frame is installed after the assembly is completed, the aforementioned process of pressing the limit frame toward the base plate 6 can be completed by tightening the tightening nut 24. The operation is relatively convenient, and the structure of the entire device is stable after tightening the tightening nut 24.
[0027] The above is only a preferred embodiment of the utility model. It should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.
Claims
1. A tensile test rock sample preparation mold, comprising a mold box, the mold box comprising a bottom plate, the top surface of the bottom plate is provided with a left plate, a right plate, a front plate and a rear plate, the left plate, the front plate, the right plate and the rear plate are sequentially connected and surround the bottom plate to form a rectangular cavity with a top opening, the rectangular cavity comprises two opposite left and right side inner walls and two opposite front and rear side inner walls, characterized in that: Two first partitions and two second partitions are arranged in the mold box, and the first partitions and the second partitions are arranged parallel to the front and rear inner walls. The bottom end of the first partition is connected to the bottom plate, one side end of the first partition is connected to the left side plate, and the two first partitions are symmetrically arranged along the center line of the left and right inner walls. The bottom end of the second partition is connected to the bottom plate, one side end of the second partition is connected to the right side plate, and the two second partitions are symmetrically arranged along the center line of the left and right inner walls. The width of the first partition plate is greater than half of the width of the front and rear inner walls, and the width of the second partition plate is the same as that of the first partition plate.
2. A tensile test rock sample preparation mold according to claim 1, characterized in that: A rectangular boss is arranged at the center of the top surface of the bottom plate, and the lower parts of the inner side walls of the left plate, the right plate, the front plate and the rear plate are respectively in contact with the four side surfaces of the boss, and the top surface of the boss forms the bottom surface of the rectangular cavity. The inner wall of the left plate and the inner wall of the right plate are both provided with a slot A and a slot B. The two side ends of the front plate are respectively arranged in the two slots A, and the two side ends of the rear plate are respectively arranged in the two slots B. It also includes a limit frame, which is sleeved on the outside of the mold box.
3. A tensile test rock sample preparation mold according to claim 2, characterized in that: The limit frame includes two inclined plates and two straight plates. The limit frame is a rectangular frame structure. The two inclined plates are arranged opposite to each other, and the two straight plates are arranged opposite to each other. The outer walls of the left plate and the right plate are fixedly provided with wedge blocks, and the wedge blocks are adapted to the inclined plates.
4. A tensile test rock sample preparation mold according to claim 3, characterized in that: It also includes a tightening screw, one end of which is fixedly connected to the bottom plate, and the other end of which passes through the straight plate and is threadedly connected with a tightening nut.
5. A tensile test rock sample preparation mold according to claim 2, characterized in that: The left side plate is provided with two first slots A, the bottom plate is provided with two first slots B, one side end of the first partition plate is inserted into the first slot A, and the bottom end of the first partition plate is inserted into the first slot B. The right side plate is provided with two second slots A, the bottom plate is provided with two second slots B, one side end of the second partition plate is inserted into the second slot A, and the bottom end of the second partition plate is inserted into the second slot B.
6. A tensile test rock sample preparation mold according to claim 5, characterized in that: The first partition plate and the second partition plate are both provided with lifting holes.