Triaxial test loading device and use method thereof

Abstract

The invention discloses a triaxial test loading device and a use method thereof, and belongs to the field of material mechanics test equipment. Comprising a connecting device I, a connecting device II, a clamp and a connecting piece, a sample plate is fixedly connected in the clamp; the connecting device I is connected to the clamp through a connecting piece; the connecting device II is arranged on the side surface of the sample plate. The device can be connected with a cross biaxial testing machine, and on the basis of a clamp, after the device is matched with different through holes, tension-shear combined loads with different proportions are applied to a sample plate under the action of a uniaxial tension load, so that a triaxial load test is carried out; according to the method, the fracture damage performance of the material sample plate under the action of the triaxial stress load can be effectively judged, meanwhile, the high requirement of a triaxial load test on experimental equipment is simplified, and the device is simple in structure and can be widely applied to industrial production tests.

Description

Technical Field

[0001] The invention relates to a triaxial test loading device and a use method thereof, and belongs to the field of material mechanics test equipment. Background Art

[0002] During the service process of structural materials, due to the variability of the service environment, the service process is accompanied by the characteristics of complex stress states. The complex stress state, that is, the stress state of the material is not a simple pure tension or pure shear, but a composite stress state of multi-directional principal stresses. Therefore, studying the strength characteristics and fracture failure morphology of materials under multi-axial loads is of great significance for the practical application of materials.

[0003] At present, researchers have designed various types of test devices to test the fracture properties of materials under complex stress states. From the perspective of application effect evaluation, most of the designed test equipment have the following shortcomings:

[0004] The designed test device is relatively complex and difficult to promote in industry;

[0005] Due to the limitations of the test equipment, most of the equipment and methods currently used for material mechanics testing can only achieve the application of loads under uniaxial and biaxial loads, without considering its mechanical behavior under triaxial loads. Therefore, it is necessary to improve it. Summary of the invention

[0006] The purpose of the present invention is to solve the above problems existing in the background technology and to provide a triaxial test loading device and a method of using the same.

[0007] The present invention achieves the above-mentioned purpose by adopting the following technical solutions:

[0008] A triaxial test loading device comprises a connecting device I, a connecting device II, a fixture and a connecting piece; a sample plate is fixedly connected in the fixture; the connecting device I is connected to the fixture through the connecting piece; the connecting device II is arranged on the side of the sample plate.

[0009] A method for using a triaxial test loading device, the method comprising the following steps:

[0010] Step 1: Fix the sample plate on the fixture;

[0011] Step 2: Fix the clamp to the connecting device I through the connecting piece;

[0012] Step 3: Install the connection device I and the connection device II on the cross biaxial testing machine and then carry out the test.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention can be connected to a cross biaxial testing machine, based on a fixture, and after matching with different perforations, under the action of a uniaxial tensile load, different proportions of tension-shear combined loads are applied to the sample plate to perform a triaxial load test, and based on this, the fracture damage performance of the material sample plate under the action of a triaxial stress load can be effectively judged, while the high requirements for experimental equipment for performing a triaxial load test are simplified, and the present invention has a simple structure and can be widely used in industrial production tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a three-dimensional structural schematic diagram of a triaxial test loading device of the present invention;

[0015] Figure 2 It is a structural schematic diagram of a connection device I of a triaxial test loading device of the present invention;

[0016] Figure 3 It is a structural schematic diagram of a connection device II of a triaxial test loading device of the present invention;

[0017] Figure 4 It is a front view of a fixture of a triaxial test loading device of the present invention;

[0018] Figure 5 It is a front view of a sample plate of a triaxial test loading device of the present invention;

[0019] Figure 6 It is a structural schematic diagram of the connection between a fixture and a sample plate of a triaxial test loading device of the present invention;

[0020] Figure 7 It is a structural schematic diagram of a threaded buckle of a triaxial test loading device of the present invention.

[0021] In the figure: 1. connecting device I; 11. supporting platform; 12. hole; 13. threaded base I; 14. threaded tube I; 15. connecting rod I; 16. circular hole I; 2. connecting device II; 21. base; 22. rectangular rod; 23. threaded base II; 24. threaded tube II; 25. connecting rod II; 26. circular hole II; 3. clamp; 31. connecting plate; 32. perforation; 33. connecting hole; 34. through hole; 4. sample plate; 41. mounting hole; 5. connecting piece; 6. threaded buckle. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] Specific implementation method 1: Figure 1-7 As shown, this embodiment describes a triaxial test loading device, including a connecting device Ⅰ1, a connecting device Ⅱ2, a fixture 3 and a connecting member 5; a sample plate 4 is fixedly connected in the fixture 3; the connecting device Ⅰ1 is connected to the fixture 3 through the connecting member 5; the connecting device Ⅱ2 is arranged on the side of the sample plate 4. The connecting member 5 is a pin or a bolt.

[0024] The sample plate 4 is formed into a large plate by plying prepreg and compacting the ply-formed plates. The sample plate 4 suitable for the size of the fixture 3 is cut from the same large plate. At the same time, cutting the sample plate from the same large plate can further reduce the discreteness of the sample plate.

[0025] The clamp 3 includes two clamps, each of which includes two connecting plates 31; each of the connecting plates 31 is set to be semicircular, and the two connecting plates 31 are arranged symmetrically at the center; through holes 34 are provided on the opposite surfaces of the two connecting plates 31; each of the connecting plates 31 is also provided with a connecting hole 33 for fixing the sample plate 4 at a position close to the through hole 34; each of the connecting plates 31 is also provided with a plurality of through holes 32 that match the connecting member 5. The sample plate 4 is provided with a mounting hole 41, and the mounting hole 41 is connected to the connecting hole 33 by bolts to fix the sample plate 4. The outer sides of the two clamps are in contact with the inner wall of the U-shaped support platform 11, and a gap is left between the two clamps, so that materials with a thickness of 3-10 mm can be fixed. When testing materials with a small thickness, a gasket can be added. Each connecting plate 31 is provided with four connecting holes 33, so that the clamp 3 can generate a uniform plane stress state on the material sample plate 4 under the action of a tensile load.

[0026] The connecting plate 31 is inclined at 58-62 degrees, so that a group of through holes 32 parallel to the vertical surface can be arranged on the connecting plate 31, thereby facilitating testing.

[0027] The perforations 32 are arranged in two rows, the two rows of perforations 32 are staggered, and the two rows of perforations 32 are distributed on the connecting plate 31 in an arc shape with the center of the circle of the corresponding connecting plate 31 as the center. The fixture 3 is provided with a plurality of perforations 32, so that the support platform 11 can cooperate with the connecting member 5 through the holes 12 and be fixed in the corresponding perforations 32, thereby changing the loading angle θ, thereby realizing different proportions of the pulling and shearing combination effect.

[0028] A line connecting a group of correspondingly located through holes 32 on the two connecting plates 31 of each of the clips is parallel to the vertical plane.

[0029] A line connecting a group of correspondingly located through holes 32 on the two connecting plates 31 of each of the clips is parallel to the horizontal plane.

[0030] The line connecting the perforations 32 of one group of corresponding positions of the two connecting plates 31 on each of the clips is at an angle of 45° to the horizontal plane. There are at least 7 groups of perforations 32. In addition to the above three groups of perforations 32 with fixed angles, the angles between the remaining perforations 32 and the horizontal plane can be measured by tools to facilitate subsequent calculations in the test.

[0031] A spacing greater than the hole diameter is provided between adjacent through holes 32 between each connecting plate 31 to avoid the distance between adjacent through holes 32 being too close, causing deformation of the test fixture 3 and thus affecting the rigor of the test.

[0032] The connecting device Ⅰ1 includes a support platform 11; a hole 12 for the connecting member 5 to pass through is provided on the side of the support platform 11, a threaded base Ⅰ13 is provided on the upper end of the support platform 11, and a threaded barrel Ⅰ14 is provided on the threaded base Ⅰ13; a connecting rod Ⅰ15 fixedly connected to the support platform 11 is provided inside the threaded barrel Ⅰ14; a threaded buckle 6 is connected to the outside of the threaded barrel Ⅰ14 by thread; a circular hole Ⅰ16 perpendicular to its central axis is provided on the upper end of the connecting rod Ⅰ15. The circular hole Ⅰ16 on the connecting rod Ⅰ15 is connected to one side of the cross biaxial testing machine through a pin, and rotates through the threaded buckle 6 to move relative to the threaded barrel Ⅰ14, so that the threaded buckle 6 is connected between the connecting rod Ⅰ15 and the cross biaxial testing machine, and the connecting rod Ⅰ15 and the cross biaxial testing machine are locked. A tensile load is applied to the fixture 3 through the cross biaxial testing machine and the connecting device Ⅰ1, that is, a combined tension and shearing action is applied to the sample plate 4.

[0033] The connecting device II2 includes a base 21; a rectangular rod 22 is fixedly connected to one side of the base 21, and a threaded base II23 is fixedly connected to the other side of the base 21, and a threaded barrel II24 is arranged on the threaded base II23; a connecting rod II25 fixedly connected to the base 21 is arranged inside the threaded barrel II24; a threaded buckle 6 is threadedly connected to the outside of the threaded barrel II24; a circular hole II26 perpendicular to its central axis is opened on the side of the connecting rod II25; the rectangular rod 22 passes through the through hole 34 and abuts against the surface of the sample plate 4. The circular hole II26 on the connecting rod II25 is connected to the other side of the cross biaxial testing machine through a pin, and the connecting rod II25 and the cross biaxial testing machine are locked by the threaded buckle 6. The rectangular rod 22 is arranged perpendicular to the plate surface of the sample plate 4, and is used to apply a compressive load to the sample plate 4, so that a triaxial load can be applied to the sample plate 4.

[0034] A method for using a triaxial test loading device, characterized in that the method comprises the following steps:

[0035] Step 1: Fix the sample plate 4 to the connection hole 33 of the connection plate 31 by means of bolts, and install two sets of displacement sensors to the top and bottom ends of the sample plate 4;

[0036] Step 2: Fix the through hole 32 on the connecting plate 31 to the hole 12 on the supporting platform 11 through the connecting piece 5;

[0037] Step three: fix the connecting rod Ⅰ15 and the connecting rod Ⅱ25 on both sides of the cross biaxial testing machine respectively. A sleeve sleeved on the corresponding connecting rod Ⅰ15 and the connecting rod Ⅱ25 is provided at the position where the cross biaxial testing machine contacts the connecting rod Ⅰ15 and the connecting rod Ⅱ25. It is fixed by a pin, and a thread is provided on the outer side of the sleeve. After the sleeve is sleeved on the outer side of the corresponding connecting rod Ⅰ15 and the connecting rod Ⅱ25, it contacts the threaded tube Ⅰ14 and the threaded tube Ⅱ24. Then, the thread buckle 6 is rotated and locked by the thread buckle 6. Then, the test can be carried out. During the test, one side of the cross biaxial testing machine applies a tensile load to the fixture 3 through the connecting device Ⅰ1, and realizes the combined tension and shear load on the specimen plate 4. The other side of the cross biaxial testing machine applies a compressive load to the specimen plate 4 through the connecting device Ⅱ2. That is, the triaxial combined load can be applied to the specimen plate 4 through the action of the cross biaxial testing machine on the fixture 3 to achieve the triaxial test conditions. Under this experimental condition, the specimen plate is destroyed.

[0038] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other forms of assembly without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0039] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A triaxial test loading device, characterized in that: The invention comprises a connecting device I (1), a connecting device II (2), a clamp (3) and a connecting piece (5); a sample plate (4) is fixedly connected inside the clamp (3); the connecting device I (1) is connected to the clamp (3) via the connecting piece (5); and the connecting device II (2) is arranged on the side of the sample plate (4).

2. A triaxial test loading device according to claim 1, characterized in that: The clamp (3) comprises two clamps, each of which comprises two connecting plates (31); each of the connecting plates (31) is configured to be semicircular, and the two connecting plates (31) are centrally symmetrically arranged; through holes (34) are provided on opposite surfaces of the two connecting plates (31); each of the connecting plates (31) is also provided with a connecting hole (33) for fixing the sample plate (4) at a position close to the through hole (34); each of the connecting plates (31) is also provided with a plurality of through holes (32) that match the connecting piece (5).

3. A triaxial test loading device according to claim 2, characterized in that: The connecting plate (31) is arranged to be inclined at an angle of 58-62 degrees.

4. A triaxial test loading device according to claim 3, characterized in that: The perforations (32) are provided in two rows, the two rows of perforations (32) are staggered, and the two rows of perforations (32) are distributed on the connection plate (31) in an arc shape with the center of the circle of the corresponding connection plate (31) as the center.

5. A triaxial test loading device according to claim 4, characterized in that: A line connecting a group of correspondingly located perforations (32) on the two connecting plates (31) on each of the clips is parallel to the vertical plane.

6. A triaxial test loading device according to claim 4, characterized in that: A line connecting a group of correspondingly located perforations (32) on the two connecting plates (31) on each of the clips is parallel to a horizontal plane.

7. A triaxial test loading device according to claim 4, characterized in that: A line connecting a group of correspondingly located perforations (32) on the two connecting plates (31) on each of the clips is at an angle of 45° to the horizontal plane.

8. A triaxial test loading device according to any one of claims 1 to 7, characterized in that: The connecting device I (1) comprises a support platform (11); a hole (12) for the connecting member (5) to pass through is provided on the side of the support platform (11); a threaded base I (13) is provided at the upper end of the support platform (11), and a threaded barrel I (14) is provided on the threaded base I (13); a connecting rod I (15) fixedly connected to the support platform (11) is provided inside the threaded barrel I (14); a threaded buckle (6) is connected to the outside of the threaded barrel I (14) by threading; and a circular hole I (16) perpendicular to its central axis is provided at the upper end of the connecting rod I (15).

9. A triaxial test loading device according to claim 8, characterized in that: The connecting device II (2) comprises a base (21); a rectangular rod (22) is fixedly connected to one side of the base (21); a threaded base II (23) is fixedly connected to the other side of the base (21); a threaded tube II (24) is arranged on the threaded base II (23); a connecting rod II (25) fixedly connected to the base (21) is arranged inside the threaded tube II (24); a threaded buckle (6) is threadedly connected to the outside of the threaded tube II (24); a circular hole II (26) perpendicular to its central axis is opened on the side of the connecting rod II (25); the rectangular rod (22) passes through the through hole (34) and is attached to the surface of the sample plate (4).

10. The method for using the triaxial test loading device according to claim 9, characterized in that: The method of use comprises the following steps: Step 1: Fix the sample plate (4) on the fixture (3); Step 2: Fix the clamp (3) to the connecting device I (1) via the connecting piece (5); Step 3: Install the connection device I (1) and the connection device II (2) on the cross biaxial testing machine and then conduct the test.

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