Tension-torsion load device and tension-torsion load test system

Abstract

The present invention provides a tension-torsion loading device and a tension-torsion loading test system that utilize the easily deformable characteristics of a parallelogram to convert the displacement of a test piece in the tensile direction into a change in the diagonal position of the parallelogram to apply a torsional load and to realize a tension-torsion loading mode by applying a tensile load. The tensile-torsion load testing system includes a tensile tester and a tensile-torsion load device, the upper load head of the tensile tester clamps the connector, and the lower load head faces the clamp head. By utilizing the easily deformable characteristics of a parallelogram, the displacement of the test piece in the tensile direction is converted into a change in the diagonal position, and a torsional load is applied, thereby realizing a tensile-torsion load method of applying a tensile load, which is significantly cheaper to purchase than a multi-axial load testing machine.

Description

[Technical field]

[0001] The present invention relates to the technical field of material testing, and in particular to a tension-torsion load device and a tension-torsion load test system thereof. [Background technology]

[0002] Multiaxial loading is a common condition for the use of major structural components in many fields such as aerospace and nuclear engineering. Under the action of multiaxial stress loading, the failure of the structure is characterized by strong suddenness and large destructiveness, so the development of multiaxial loading testing technology and equipment for materials has attracted widespread attention in the fields of engineering and science. At present, the commonly used tensile-torsion loading test equipment is mainly tensile-torsion loading test system, and the existing tensile-torsion loading test system is an electrohydraulic servo testing system, which can meet the complex requirements of static and dynamic testing of materials and structures and perform axial, torsional and tensile-torsion loading tests, and its core member is the multiaxial hydraulic servo testing machine. However, the multiaxial hydraulic servo testing machine is usually expensive, and the price of one unit can reach up to 4 million RMB, so the high acquisition cost limits the research on multiaxial loading of materials and structures in the field of engineering and scientific research. Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention aims to solve the above technical problems and to provide a tensile-torsion loading device and a tensile-torsion loading test system thereof, which utilizes the easily deformable characteristics of a parallelogram to convert the displacement of a test piece in the tensile direction into a change in the diagonal position of the parallelogram to apply a torsional load, and apply a tensile load to realize a tensile-torsion loading mode. The manufacturing cost of the tensile-torsion loading device is negligibly low compared to that of a tensile testing machine, and since the tensile testing machine is a uniaxial testing machine, the purchase cost is significantly lower than that of a multiaxial loading testing machine. [Means for solving the problem]

[0004] In order to achieve the above object, the present invention provides the following solution: The present invention discloses a tensile-torsion loading device, including a connector, a clamp head, and a connecting rod assembly, the connector is arranged to be clamped by an upper load head of a tensile tester, the clamp head is arranged to clamp one end of a test specimen, and the other end of the test specimen is arranged to be clamped by a lower load head of the tensile tester, the connecting rod assembly includes four horizontal connecting rods and four inclined connecting rods, the four horizontal connecting rods are hinged sequentially at their heads and tails to form a parallelogram structure, and the hinges of the four horizontal connecting rods are hinged. the hinge connection axes are arranged vertically, two of the four horizontal connecting rods are longer than the other two, the four diagonals of the parallelogram structure are hinged to one end of the four inclined connecting rods respectively, the other ends of the inclined connecting rods at two diagonals are hinged to the connector, the hinge connection axes of the hinge connection points of the connector are horizontal and perpendicular to the connection lines of the corresponding two diagonals, and the other ends of the inclined connecting rods at the other two diagonals are hinged to the clamp head, the hinge connection axes of the hinge connection points of the clamp head are horizontal and perpendicular to the connection lines of the corresponding two diagonals.

[0005] Preferably, the connection lines between the hinge connection points of the connector and the two inclined connecting rods are shorter than the connection lines of the corresponding two diagonals, and the connection lines between the hinge connection points of the clamp head and the two inclined connecting rods are shorter than the connection lines of the corresponding two diagonals.

[0006] Preferably, the horizontal connecting rod and the inclined connecting rod are both rectangular rods.

[0007] Preferably, the horizontal connecting rod and the inclined connecting rod are rigid rods.

[0008] Preferably, the centerlines of the clamping openings of the upper load head, the lower load head and the clamping head are on the same vertical line.

[0009] A tensile-torsional load testing system is further disclosed, comprising a tensile tester and the above tensile-torsional load device, an upper load head of the tensile tester clamps the connector and a lower load head of the tensile tester faces the clamp head of the tensile-torsional load device. Effect of the Invention

[0010] Compared with the prior art, the present invention achieves the following technical advantages: 1. In the tensile-torsion loading device of the present invention, it is mounted on a tensile testing machine, and when the upper load head of the tensile testing machine moves upward, an axial tensile load is applied to the test specimen by the connecting rod assembly; at the same time, by utilizing the easy deformation characteristics of the parallelogram structure, the parallelogram structure of the connecting rod assembly generates a rotation angle during the deformation process, thereby transmitting the torsional force to the test specimen, thereby achieving the purpose of combining tensile and torsional loading; the manufacturing cost of this tensile-torsion loading device is negligible compared with that of the tensile testing machine, and because the tensile testing machine is a uniaxial testing machine, its purchase cost is significantly lower than that of a multiaxial loading testing machine. 2. The tensile-torsion load testing system of the present invention is mainly composed of a tensile testing machine and a tensile-torsion loading device. After being combined, it can be pulled and twisted. The cost of the entire system is mainly the tensile testing machine, and the tensile testing machine is a uniaxial testing machine, so the purchase cost is significantly lower than that of a multiaxial loading testing machine. [Brief description of the drawings]

[0011] In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings that need to be used in the embodiments; obviously, the drawings in the following description are only some embodiments of the present invention, and those skilled in the art can also obtain other drawings based on these drawings without creative efforts.

[0012] [Figure 1] FIG. 1 is a front structural schematic diagram of a tension-torsion load testing system (before tension-torsion). [Diagram 2] FIG. 2 is a schematic diagram of the three-dimensional structure of a tension-torsion loading device (before tension-torsion). [Diagram 3] FIG. 2 is a schematic top view of the structure of a tensile-torsion loading device (before tensile-torsion). [Figure 4] FIG. 1 is a schematic front view of the tension-torsion load test system (during tension-torsion). [Diagram 5] FIG. 2 is a schematic diagram of the three-dimensional structure of a tension-torsion loading device (during tension-torsion). [Figure 6] FIG. 2 is a schematic top view of the structure of a tensile-torsion load device (during tensile-torsion). [Figure 7] FIG. 1 is a diagram illustrating the principle of deformation of a parallelogram structure in a tension-torsion loading device. [Figure 8] FIG. 2 is a front view of the sheet test piece. [Figure 9] FIG. 2 is a top view of the sheet test specimen. [Figure 10] FIG. 2 is a front view of the columnar test piece. [Figure 11] FIG. 2 is a top view of the columnar test specimen. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention, and obviously, the described embodiments are only a part of the embodiments of the present invention, and are not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts are all within the protection scope of the present invention.

[0014] Example 1 This embodiment provides a tension-torsion load device, which includes a connector 1, a clamp head 2 and a connecting rod assembly, as shown in Fig. 1 to Fig. 11. The connecting rod assembly includes four horizontal connecting rods 3 and four inclined connecting rods 4, and the four horizontal connecting rods 3 are hinged sequentially at their heads to form a parallelogram structure, and the hinge connection lines of the four horizontal connecting rods 3 are installed in a vertical direction. Two of the four horizontal connecting rods 3 are longer than the other two, and both ends of the two long horizontal connecting rods 3 are hinged respectively to the two short horizontal connecting rods 3, so that the parallelogram structure forms a standard parallelogram with two long sides and two short sides. The four diagonals of the parallelogram structure are hinged respectively to one end of the four inclined connecting rods 4. The other ends of the inclined connecting rods 4 at two of the diagonals were hinged to the connector 1. The hinge connection axes of the hinge connection points between the two inclined connecting rods 4 and the connector 1 were horizontal and perpendicular to the connection lines (i.e., diagonals) of the corresponding two diagonals of the two inclined connecting rods 4. The other ends of the inclined connecting rods 4 at the other two diagonals were hinged to the clamp head 2. The hinge connection axes of the hinge connection points between the two inclined connecting rods 4 and the clamp head 2 were horizontal and perpendicular to the connection lines (i.e., diagonals) of the corresponding two diagonals of the two inclined connecting rods 4. The clamping mouth of the clamp head 2 faced downward, and the back side of the clamping mouth of the clamp head 2 was hinged to the inclined connecting rods 4.

[0015] Working principle: First, the connector 1 is clamped to the upper load head 5 of the tensile tester, one end of the test piece 7 is clamped to the lower load head 6 of the tensile tester, and the other end of the test piece 7 is clamped to the clamp head 2. At this time, the four horizontal connecting rods 3 forming a parallelogram structure are located in the same horizontal plane. The tensile tester used here is a one-way tensile device, that is, the upper load head 5 and the lower load head 6 of the tensile tester can only move up and down relative to each other, and cannot twist, that is, the tensile tester only plays the role of tension and cannot play the role of torsion. Such a tensile tester has a lower purchase cost than a multi-axis fatigue tester, and the upper load head 6 of the tensile tester can only move up and down relative to each other, and cannot twist. When the load head 5 moves upward, the connector 1 moves upward, and the two inclined connecting rods 4 above the parallelogram structure composed of four horizontal connecting rods 3 deform the parallelogram structure composed of four horizontal connecting rods 3, and then pull the two inclined connecting rods 4 below the parallelogram structure, so as to apply an axial tensile load to the test specimen 7, at this time, the four horizontal connecting rods 3 are still in the same horizontal plane, and the parallelogram structure is deformed in its plane, and a rotation angle δα is generated during the deformation process, and a torsional force is transmitted to the test specimen 7, as shown in Figure 3, and the purpose of combining tensile and torsional loads is achieved.

[0016] This tensile-torsional loading device has a novel and simple structure, is compact, easy to install and disassemble, easy to use, has low manufacturing costs, and can be combined with a conventional uniaxial tensile testing machine to achieve the purpose of multiaxial loading testing of materials and structures. The test piece 7 may be cylindrical or sheet-shaped, and the shape diagrams of commonly used test pieces 7 are shown in Figures 8 to 11. The material of the test piece 7 is not limited to metal, but may be a composite material.

[0017] 1 to 11, in this embodiment, the connection line of the hinge connection points of the two inclined connecting rods 4 hingedly connected to the connector 1 is shorter than the connection lines (diagonal lines) of the two diagonals corresponding to the two inclined connecting rods 4. The connection line of the hinge connection points of the two inclined connecting rods 4 hingedly connected to the clamp head 2 is shorter than the connection lines (another diagonal line) of the two diagonals corresponding to the two inclined connecting rods 4.

[0018] In this embodiment, as shown in Figures 1 to 11, the two inclined connecting rods 4 above the parallelogram structure had the same length, and the two inclined connecting rods 4 below the parallelogram structure had the same length.

[0019] In this embodiment, the horizontal connecting rod 3 and the inclined connecting rod 4 are both rectangular rods, as shown in Figures 1 to 11. Of course, square rods and rods of other shapes can also be used, but rectangular rods are optimal.

[0020] Furthermore, in this embodiment, as shown in Figs. 1 to 11, the horizontal connecting rod 3 and the inclined connecting rod 4 are made of metal rods such as steel rods or other rods with high rigidity.

[0021] Furthermore, in this embodiment, as shown in Figs. 1 to 11, the center lines of the upper load head 5, the lower load head 6 and the clamp mouth of the clamp head 2 were on the same vertical line.

[0022] In this embodiment, as shown in Figures 1 to 11, the hinge connection methods between the horizontal connecting rods 3, the hinge connection method between the inclined connecting rods 4 and the parallelogram structure, the hinge connection method between the inclined connecting rods 4 and the connecting head 1, and the hinge connection method between the inclined connecting rods 4 and the clamping head 2 are all axial hinge connections. Further, in this embodiment, as shown in FIG. 1 to FIG. 11, the horizontal connecting rod 3 and the inclined connecting rod 4 are hinge-connected via a hinge sheet 8, and the hinge sheet 8 has three hinge heads, namely, a first hinge head, a second hinge head and a third hinge head, the first hinge head and the second hinge head are on the same line, the hinge connection axes of the first hinge head and the second hinge head are installed vertically, and the first hinge head and the second hinge head are hinge-connected to one end of each of the two horizontal connecting rods 3, and the third hinge head is perpendicular to the connection line between the first hinge head and the second hinge head, the hinge connection axis of the third hinge head is installed horizontally, and the third hinge head is hinge-connected to one end of the inclined connecting rod 4.

[0023] Example 2 This embodiment provides a tensile-torsion load testing system, which includes a tensile tester and the tensile-torsion load device of embodiment 1, as shown in Figures 1 to 11. The upper load head 5 of the tensile tester clamps the connector 1, and the lower load head 6 of the tensile tester faces the clamp head 2 of the tensile-torsion load device. This tensile tester is a one-way tensile device, that is, the upper load head 5 and the lower load head 6 of the tensile tester can only move up and down relative to each other and cannot twist, so this tensile tester only plays a tensile role and cannot play a torsional role, and such a tensile tester has a lower purchase cost than a multi-axis fatigue tester.

[0024] Working principle: First, one end of the test piece 7 is clamped to the lower load head 6 of the tensile tester, and the other end of the test piece 7 is clamped to the clamp head 2, at this time, the four horizontal connecting rods 3 forming a parallelogram structure are located in the same horizontal plane, then, when the upper load head 5 of the tensile tester moves upward, the connector 1 moves upward, and the two inclined connecting rods 4 on the parallelogram structure composed of the four horizontal connecting rods 3 deform the parallelogram structure, then, the two inclined connecting rods 4 below the parallelogram structure are pulled, and an axial tensile load is applied to the test piece 7, at this time, the four horizontal connecting rods 3 are still in the same horizontal plane, and the parallelogram structure is deformed in its plane, and a rotation angle δα is generated during the deformation process, as shown in Figure 3. Thus, the torsional force is transmitted to the test piece 7, and the purpose of combining tensile and torsional load is achieved.

[0025] This tensile torsion load test system is composed of a tensile torsion load device and a conventional tensile test machine, and the main cost is in the tensile test machine. The manufacturing cost of the tensile torsion load device is almost negligible compared to the tensile test machine, and since the tensile test machine is a uniaxial test machine, the purchase cost is significantly lower than that of a multiaxial load test machine. The test piece 7 may be cylindrical or sheet-shaped, and the shape diagrams of commonly used test pieces 7 are shown in Figures 8 to 11. The material of the test piece 7 is not limited to metal, but may be a composite material.

[0026] The present invention uses specific examples to explain the principles and embodiments of the present invention, and the above description of the examples is only used to help understand the method and core idea of ​​the present invention, and at the same time, those skilled in the art may change the specific embodiments and application scope according to the spirit of the present invention. There are changes in the form for implementing the invention and the application scope. In summary, the contents of this specification should not be understood as limiting the present invention. [Explanation of symbols]

[0027] 1 Connector 2 Clamp head 3 Horizontal connecting rod 4 Inclined connecting rod 5. Upper Load Head 6 Lower Load Head 7 Test Pieces 8 Hinge Sheet

Claims

1. a tension-torsion loading apparatus including a connector, a clamping head, and a connecting rod assembly, the connector being positioned to be clamped by an upper load head of a tensile tester, the clamping head being positioned to clamp one end of a test specimen, and the other end of the test specimen being positioned to be clamped by a lower load head of the tensile tester; The connecting rod assembly includes four horizontal connecting rods and four inclined connecting rods, the four horizontal connecting rods are hinged sequentially at their ends to form a parallelogram structure, the hinge connection axes of the four horizontal connecting rods are arranged in a vertical direction, two of the four horizontal connecting rods are longer than the other two, and the four diagonals of the parallelogram structure are hinged to one end of the four inclined connecting rods, respectively. the other ends of the inclined connecting rods at the two diagonals are hingedly connected to the connector, and the hinge connection axis of the hinge connection point of the connector is horizontal and perpendicular to the connection line of the corresponding two diagonals, and the other ends of the inclined connecting rods at the other two diagonals are hingedly connected to the clamp head, and the hinge connection axis of the hinge connection point of the clamp head is horizontal and perpendicular to the connection line of the corresponding two diagonals.

2. The tensile-torsional loading device of claim 1, characterized in that the connection line between the connector and the hinge connection points of the two inclined connecting rods is shorter than the connection lines of the corresponding two diagonals, and the connection line between the clamp head and the hinge connection points of the two inclined connecting rods is shorter than the connection lines of the corresponding two diagonals.

3. 2. The tension-torsion loading device according to claim 1, wherein the horizontal connecting rod and the inclined connecting rod are both rectangular rods.

4. 2. The tension-torsion loading device according to claim 1, wherein the horizontal connecting rod and the inclined connecting rod are rigid rods.

5. 2. The tension and torsion loading device according to claim 1, wherein the center lines of the clamping openings of said upper load head, said lower load head and said clamping head are aligned on the same vertical line.

6. 1. A tension-torsion load testing system comprising: A method for testing a specimen comprising: a tensile tester and a tensile / torsional loading device according to any one of claims 1 to 5; A tensile-torsion load testing system, characterized in that an upper load head of the tensile tester clamps the connector, and a lower load head of the tensile tester faces a clamp head of the tensile-torsion load device.

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