Rock direct tensile test device capable of avoiding eccentric bending moment

Abstract

The utility model discloses a rock direct tensile test device capable of avoiding eccentric bending moment, which comprises two clamping pieces which are used for clamping rock and are oppositely arranged up and down, the clamping piece on the upper side is arranged on a supporting assembly through a tensile assembly, and an upper anti-eccentric assembly is arranged between the clamping piece on the upper side and the tensile assembly; the clamping piece on the lower side is arranged on the supporting assembly, and a lower anti-eccentricity assembly is arranged between the clamping piece on the lower side and the supporting assembly. The whole structure is simple, dismounting and carrying are convenient, the device can be used for outdoor on-site testing, damage to rock samples in the transportation process is reduced, and data accuracy is guaranteed; meanwhile, direct tensile tests of different types of rock tests can be realized by disassembling the clamping piece; anti-eccentric assemblies are arranged at the connecting positions of the upper clamping piece and the lower clamping piece and the other parts, so that eccentric bending moment generated in the direct tensile test process can be effectively eliminated, and the accuracy of test data is further ensured.

Description

TECHNICAL FIELD

[0001] The utility model belongs to rock mechanics technical field, concretely relates to a rock direct tensile test device of avoiding eccentric bending moment. BACKGROUND

[0002] Direct tensile test is one of central research means of studying rock mechanics property, through direct tensile test, can comprehensively understand the mechanical response of rock under the action of tension, including elasticity, plasticity, strength and other characteristics. At present, rock direct tensile test device is mostly set in the test room, and the overall volume is relatively large, so that only the fixed position can be tested during the test, that is, it is limited by the site, and the rock sample taken on site will also be damaged to different degrees when being transported to the test room, so that the rock mechanics parameters cannot be accurately measured in the first time.

[0003] Although part of the device has the characteristics of portability, so that it can be used for on-site rock direct tensile test, but it cannot avoid the generation of eccentric bending moment in the tensile process. When the tensile load is small, the eccentric bending moment generated is small, but when the tensile load gradually increases, the eccentric bending moment increases, which will cause large deviation of the test results, and it is difficult to ensure the accuracy of the data results. UTILITY MODEL CONTENT

[0004] The utility model proposes a rock direct tensile test device of avoiding eccentric bending moment, which can effectively eliminate the generation of eccentric bending moment while meeting the requirements of portability and on-site test, so as to ensure the test accuracy.

[0005] Therefore, the utility model adopts the technical scheme of a rock direct tensile test device of avoiding eccentric bending moment, which comprises two clamping parts for clamping rock and arranged oppositely up and down, the upper clamping part is arranged on the support assembly through the tensile assembly, and an upper anti-eccentric assembly is arranged between the upper clamping part and the tensile assembly, and the lower clamping part is arranged on the support assembly, and a lower anti-eccentric assembly is arranged between the lower clamping part and the support assembly.

[0006] As a preferred embodiment of the above-mentioned scheme, the support assembly comprises a base, a limiting top plate is arranged above the base, and at least two vertical columns are arranged between the limiting top plate and the base, the upper end of the vertical column is provided with an external thread, and a fixing nut for fixing the position of the limiting top plate is arranged on each vertical column.

[0007] Further preferably, the tensile assembly comprises a tensile top plate and at least two vertical double-head cylinders, the telescopic rod at the lower end of each double-head cylinder is arranged on the support assembly, and the tensile top plate is arranged on the telescopic rod at the upper end of all double-head cylinders.

[0008] Further preferably, the upper eccentricity resisting assembly and the lower eccentricity resisting assembly are identical in structure, each comprising a connecting piece arranged on a corresponding component part, the connecting piece being provided with at least two first connecting plates arranged at intervals thereon, the clamping piece being provided with at least two second connecting plates arranged at intervals thereon, and the first connecting plates and the second connecting plates being arranged in a vertically symmetrical manner, a connecting shaft being arranged through all the first connecting plates and all the second connecting plates, and an eccentricity resisting piece being arranged between any two adjacent first connecting plates.

[0009] Further preferably, the eccentricity resisting piece comprises a first connecting block, a second connecting block and a connecting ring, the connecting ring being arranged between the first connecting block and the second connecting block and sleeved on the connecting shaft, a through hole for the connecting shaft to pass through being horizontally arranged through the first connecting block and the second connecting block, a recess for the connecting ring to be accommodated being coaxially arranged on one side of the through hole of the first connecting block close to the second connecting block, and a protrusion for the connecting ring to be sleeved being coaxially arranged on one side of the through hole of the second connecting block close to the first connecting block.

[0010] Further preferably, the connecting shafts on the upper eccentricity resisting assembly and the connecting shafts on the lower eccentricity resisting assembly are arranged in a horizontal and perpendicular manner.

[0011] Further preferably, the connecting piece comprises a limiting piece for connecting with the corresponding component part, one end of the limiting piece being arranged as a ball head, the other end of the limiting piece being provided with a limiting connecting piece for preventing the ball head from being separated from the corresponding component part after passing through the corresponding component part, and a certain distance being left between the limiting connecting piece and the corresponding component part when being stretched.

[0012] Further preferably, the clamping piece is provided with an accommodating groove for accommodating a rock sample, a plurality of clamping pieces are arranged, and the accommodating grooves on each pair of clamping pieces can be arranged in a shape corresponding to a circular, square or dog bone shaped rock sample.

[0013] The utility model discloses the beneficial effects of:

[0014] 1) The overall structure is simple, convenient to disassemble and carry, can be used for outdoor field test, reduces the damage in the transportation process of rock sample, guarantees the accuracy of data, and can realize direct tensile test of different types of rock test by disassembling the clamping piece.

[0015] 2) The upper and lower clamping pieces and the rest of the component parts are provided with eccentricity resisting assemblies at the connecting positions, can effectively eliminate the eccentric bending moment generated in the direct tensile test process, and further guarantee the accuracy of test data. DRAWINGS

[0016] Figure 1 The utility model discloses the beneficial effects of:

[0017] Figure 2It is the schematic view of eccentric resistance piece (each part includes front view and side view).

[0018] Figure 3 It is Figure 1 The enlarged view of A.

[0019] Figure 4 It is Figure 1 The enlarged view of B.

[0020] Figure 5 It is the schematic view of the clamping piece with different shape accommodating grooves in the utility model.

[0021] The drawing label: base-1, limit top plate-2, stand-3, fixed nut-4, stretch top plate-5, buffer pad-6, limit piece-7, telescopic rod-8, double head cylinder-9, oil inlet pipeline-10, limit connecting piece-11, eccentric resistance piece-12, first connecting block-1201, second connecting block-1202, connecting ring-1203, connecting shaft-13, clamping piece-14, rock sample-15. DETAILED DESCRIPTION

[0022] The utility model will be further described in the embodiment and in conjunction with the drawings:

[0023] As Figures 1-5 The rock direct tensile test device for avoiding eccentric bending moment mainly comprises a clamping piece 14, a stretching assembly, a supporting assembly, an upper eccentric resistance assembly and a lower eccentric resistance assembly. The clamping piece 14 is used for clamping rock and is arranged oppositely in two layers. The upper clamping piece 14 is arranged on the supporting assembly through the stretching assembly, and the upper clamping piece 14 and the stretching assembly are provided with the upper eccentric resistance assembly. The lower clamping piece 14 is arranged on the supporting assembly, and the lower clamping piece and the supporting assembly are provided with the lower eccentric resistance assembly.

[0024] The supporting assembly comprises a base 1, and a limit top plate 2 is arranged above the base 1. At least two stand columns 3 are arranged between the limit top plate 2 and the base 1, and preferably, four stand columns 3 are arranged in a rectangular manner. An outer thread is arranged at the upper end of the stand column 3, and a fixed nut 4 for fixing the position of the limit top plate 2 is arranged on each stand column 3. Preferably, a protective net is detachably arranged outside the stand column, and the protective net can also be a transparent protective cover, so as to reduce external interference during the test.

[0025] The stretching assembly comprises a stretching top plate 5 and at least two vertically arranged double-head cylinders 9, the telescopic rods 8 at the lower ends of each double-head cylinder 9 being arranged on the supporting assembly, and the stretching top plate 5 being arranged on the telescopic rods at the upper ends of all double-head cylinders 9. The double-head cylinders are arranged inside the upright columns, and a buffer pad 6 is arranged above the stretching top plate to prevent the stretching top plate from directly abutting against the limiting top plate during stretching. Preferably, the double-head cylinders are double-head oil cylinders, and an oil inlet pipeline 10 is arranged on each double-head cylinder to realize the operation of the double-head cylinder.

[0026] The upper eccentricity resisting assembly and the lower eccentricity resisting assembly have the same structure, and each comprises a connecting piece arranged on a corresponding part, at least two first connecting plates arranged on the connecting piece in an interval, at least two second connecting plates arranged on the clamping piece 14 in an interval, and the first connecting plates and the second connecting plates being arranged in an upper-lower symmetrical manner, a connecting shaft 13 being arranged through all the first connecting plates and all the second connecting plates, and an eccentricity resisting piece 12 being arranged between any two adjacent first connecting plates.

[0027] The eccentricity resisting piece 12 comprises a first connecting block 1201, a second connecting block 1202 and a connecting ring 1203. The first connecting block 1201 and the second connecting block 1202 are both horizontally provided with through holes for the connecting shaft 13 to pass through, and the connecting ring 1203 is arranged between the first connecting block 1201 and the second connecting block 1202 and is sleeved on the connecting shaft 13. In order to realize the installation of the connecting ring, a recess for accommodating the connecting ring 1203 is coaxially arranged on one side of the through hole of the first connecting block 1201 close to the second connecting block 1202, and a protrusion for the connecting ring 1203 to be sleeved is coaxially arranged on one side of the through hole of the second connecting block 1202 close to the first connecting block 1201, that is, one end of the connecting ring is sleeved on the protrusion, and the other end is inserted into the recess. The diameter of the through hole is in clearance fit with the connecting shaft, and the inner diameter of the connecting ring is in interference fit with the connecting shaft.

[0028] In order to ensure the effect of the overall eccentricity resisting bending moment, the connecting shafts 13 on the upper eccentricity resisting assembly and the connecting shafts 13 on the lower eccentricity resisting assembly are arranged in a horizontal and perpendicular manner, and the first connecting plates and the second connecting plates on the upper and lower sides are also arranged in a horizontal and perpendicular manner, that is, the two connecting shafts are arranged in a horizontal and orthogonal manner, so that the generation of the eccentric bending moment can be prevented from two directions, thereby further eliminating the eccentric bending moment and ensuring the accuracy of the test data.

[0029] To facilitate the installation of rock samples, clamps, and anti-eccentricity components, the connector includes a limiting member 7 for connecting to the corresponding components. One end of the limiting member 7 is a ball head, and both the base and the tensioning top plate have mounting holes to accommodate the ball head. A small end is provided on the side of the mounting hole facing the clamp, preventing one end of the limiting member from moving out of the mounting hole. Simultaneously, the other end of the limiting member 7, after passing through the corresponding component, has a limiting connector 11 to prevent the ball head from detaching from the corresponding component. During tensioning, a certain distance is maintained between the limiting connector 11 and the corresponding component; this distance serves as the distance for the connector to move up and down during clamp installation. Preferably, the other end of the limiting member has a threaded section that can be screwed onto the limiting connector, facilitating the installation of the connector onto the corresponding component.

[0030] like Figure 1 and 5 As shown, the clamping member 14 is provided with a receiving groove for accommodating rock samples. There are several clamping members, and the receiving groove on each pair of clamping members can be set to correspond to the shape of rock samples such as round, square, and dog bone, so that it can clamp different types of rock samples.

[0031] Based on the above-mentioned testing apparatus, a method for direct tensile testing of rock includes the following steps:

[0032] The first step is to install the rock specimens. Rock specimens 15 of the required size are prepared and placed into the corresponding receiving grooves of the two clamping members 14. The receiving grooves are coated with an adhesive for fixing the rock specimens 15. The rock specimens are made from field-sourced rock and can be used for both standard and small-sized specimen tests. For example, cylindrical rock specimens can have diameters of 10mm, 20mm, 30mm, 40mm, and 50mm. High-viscosity epoxy resin is used as the adhesive.

[0033] The second step involves assembling the test apparatus. First, the anti-eccentricity component 12 is assembled. Then, the clamping component 14 is installed on the connecting component via the connecting shaft 13 and the anti-eccentricity component 12. Specifically, one end of the connecting ring is first fitted onto the protrusion, and the other end is inserted into the groove. Then, the anti-eccentricity component is connected to the connecting component and the clamping component via two connecting shafts, respectively. The directions of the connecting shafts located on the upper and lower sides of the clamping component are perpendicular to each other.

[0034] The third step is to conduct the test. The double-headed cylinder 9 is activated to start the direct tensile test on the rock. After the rock sample 15 fails under tension, the corresponding data is recorded, and the broken rock sample and adhesive on the clamping part 14 are cleaned.

Claims

1. A rock direct tension testing device for avoiding eccentric bending moment, comprising two clamping members (14) for clamping rock and arranged oppositely up and down, characterized in that: The upper clamping piece (14) is arranged on the support assembly through a stretching assembly, and an upper anti-eccentricity assembly is arranged between the upper clamping piece (14) and the stretching assembly; the lower clamping piece (14) is arranged on the support assembly, and a lower anti-eccentricity assembly is arranged between the lower clamping piece and the support assembly.

2. The rock direct tension testing apparatus to avoid eccentric bending moment as claimed in claim 1 wherein: The support assembly comprises a base (1), and a limiting top plate (2) is arranged above the base (1), and at least two vertical columns (3) are arranged between the limiting top plate (2) and the base (1), the upper end of each column (3) is provided with external threads, and a fixing nut (4) for fixing the position of the limiting top plate (2) is arranged on each column (3).

3. The rock direct tension testing apparatus to avoid eccentric bending moment as claimed in claim 1 wherein: The stretching assembly comprises a stretching top plate (5) and at least two vertical double-head cylinders (9), the telescopic rod (8) at the lower end of each double-head cylinder (9) is arranged on the support assembly, and the stretching top plate (5) is arranged on the telescopic rod at the upper end of each double-head cylinder (9).

4. The rock direct tension testing apparatus to avoid eccentric bending moment as claimed in claim 1 wherein: The upper anti-eccentricity assembly and the lower anti-eccentricity assembly have the same structure, and each comprises a connecting piece arranged on a corresponding component, at least two first connecting plates are arranged on the connecting piece at intervals, at least two second connecting plates are arranged on the clamping piece (14) at intervals, the first connecting plates and the second connecting plates are arranged symmetrically, a connecting shaft (13) is arranged on each first connecting plate and each second connecting plate, an anti-eccentricity piece (12) is arranged between two connecting shafts (13), and an anti-eccentricity piece (12) is arranged between any two adjacent first connecting plates.

5. The rock direct tension testing apparatus to avoid eccentric bending moment as claimed in claim 4 wherein: The anti-eccentricity piece (12) comprises a first connecting block (1201), a second connecting block (1202) and a connecting ring (1203), the connecting ring (1203) is arranged between the first connecting block (1201) and the second connecting block (1202) and is sleeved on the connecting shaft (13) outside, through holes for the connecting shaft (13) to pass through are horizontally arranged on the first connecting block (1201) and the second connecting block (1202), a groove for accommodating the connecting ring (1203) is coaxially arranged on one side of the through hole on the first connecting block (1201) close to the second connecting block (1202), and a protrusion for the connecting ring (1203) to be sleeved is coaxially arranged on one side of the through hole on the second connecting block (1202) close to the first connecting block (1201).

6. The rock direct tension testing apparatus to avoid eccentric bending moment as claimed in claim 4 wherein: The connecting shafts (13) on the upper anti-eccentricity assembly and the connecting shafts (13) on the lower anti-eccentricity assembly are arranged horizontally and perpendicularly to each other.

7. The rock direct tension testing apparatus to avoid eccentric bending moment as claimed in claim 4 wherein: The connecting piece comprises a limiting piece (7) for connecting with a corresponding component, one end of the limiting piece (7) is provided with a ball head, the other end of the limiting piece (7) is provided with a limiting connecting piece (11) for preventing the ball head from separating from the corresponding component after passing through the corresponding component, and a certain distance is left between the limiting connecting piece (11) and the corresponding component during stretching.

8. The rock direct tension testing apparatus to avoid eccentric bending moment as claimed in claim 1 wherein: The clamping piece (14) is provided with a containing groove for containing a rock sample, a plurality of clamping pieces are arranged, and the containing grooves on each pair of clamping pieces can be arranged in a shape corresponding to a circular, square or dog bone-shaped rock sample.

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