Tension-torsion loading device and tension-torsion loading test system thereof

Abstract

To provide a tension and torsion load device and a tension and torsion load test system for realizing a tension-torsion load mode by applying a torsion load by converting the displacement of a test piece in the tensile direction into the change of the diagonal line position of a parallelogram by using the easily deformable characteristics of the parallelogram, and applying a tension load.SOLUTION: The tension-torsion load testing system includes a tension testing machine and a tension-torsion loading device, an upper loading head of the tension testing machine clamps the connector, and a lower loading head is opposite to the clamping head. To realize a tensile and torsional load system for converting the displacement in the tensile direction of a test piece into the change of the position of a diagonal line, applying a torsional load and applying a tensile load by utilizing the easily deformable characteristics of a parallelogram and to sharply reduce a purchase cost as compared with a multiaxial load testing machine.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Multiaxial loading is a common operating condition for major structural components in many fields, including aerospace and nuclear engineering. Because structural failure under multiaxial stress loading is characterized by its suddenness and destructive potential, the development of multiaxial loading testing techniques and equipment for materials has attracted widespread attention in engineering and scientific fields. Currently, commonly used tension-torsion load testing equipment is primarily tension-torsion load testing systems. Existing tension-torsion load testing systems are electrohydraulic servo testing systems, which can meet the complex requirements of static and dynamic testing of materials and structures and perform axial, torsional, and tension-torsion load testing. Multiaxial servo hydraulic testing machines are the core component. However, multiaxial servo hydraulic testing machines are typically expensive, costing up to 4 million RMB per unit. This high acquisition cost has limited research on multiaxial loading of materials and structures in 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 tension-torsion loading device and a tension-torsion loading test system that utilizes the easily deformable characteristics of a parallelogram to convert the displacement of a test specimen 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 achieve a tension-torsion loading mode.The manufacturing costs of a tension-torsion loading device are negligible compared to tensile testing machines, and because a tensile testing machine is a uniaxial testing machine, its purchase cost is significantly lower than that of a multiaxial loading testing machine. [Means for solving the problem]

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

[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 diagonal 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 tension-torsion load testing system is further disclosed, comprising a tensile tester and the above-described tension-torsion load device, wherein 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 tension-torsion load device. [Effects of the Invention]

[0010] Compared with the prior art, the present invention achieves the following technical advantages: 1. The tension-torsion loading device of the present invention is attached to a tensile testing machine. When the upper load head of the tensile testing machine moves upward, the connecting rod assembly applies an axial tensile load to the test specimen. At the same time, by utilizing the easily deformable characteristics of the parallelogram structure, the parallelogram structure of the connecting rod assembly generates a rotation angle during the deformation process, thereby transmitting a torsional force to the test specimen, thereby achieving the purpose of combining tension and torsion loading. The manufacturing cost of this tension-torsion loading device is negligible compared to that of a tensile testing machine. Since 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 tester and a tensile-torsion load device. After being combined, it can be used for pulling and twisting. The cost of the entire system is mainly the tensile tester. Since the tensile tester is a uniaxial tester, the purchase cost is significantly lower than that of a multiaxial load testing machine. [Brief explanation 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 any creative efforts.

[0012] [Figure 1] FIG. 1 is a front structural schematic diagram of a tension-torsion load testing system (before tension-torsion). [Figure 2] FIG. 1 is a schematic diagram of the three-dimensional structure of a tension-torsion loading device (before tension-torsion). [Figure 3] FIG. 2 is a schematic top view of the structure of a tension-torsion loading device (before tension-torsion). [Figure 4] FIG. 1 is a front structural schematic diagram of a tension-torsion load testing system (during tension-torsion). [Figure 5] FIG. 1 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 the tension-torsion load device (during tension-torsion). [Figure 7] FIG. 10 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. 1 is a top view of a sheet test specimen. [Figure 10] FIG. 1 is a front view of a columnar test specimen. [Figure 11] FIG. 1 is a top view of a columnar test specimen. DETAILED DESCRIPTION OF THE INVENTION

[0013] The following provides a clear and complete description of the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and are not all of the embodiments, and all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without any creative efforts fall within the scope of protection of the present invention.

[0014] Example 1 This embodiment provides a tension-torsion loading device, which, as shown in Figures 1 to 11, includes a connector 1, a clamp head 2, and a connecting rod assembly. The connecting rod assembly includes four horizontal connecting rods 3 and four inclined connecting rods 4. The four horizontal connecting rods 3 are hinged sequentially at their ends to form a parallelogram structure, with the hinge connections of the four horizontal connecting rods 3 arranged vertically. 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 hingedly connected to the two short horizontal connecting rods 3, respectively. As a result, the parallelogram structure forms a standard parallelogram with two long sides and two short sides. The four diagonal corners of the parallelogram structure are hingedly connected to one end of the four inclined connecting rods 4, respectively. The other ends of the inclined connecting rods 4 at two of the diagonal corners were hingedly connected to the connector 1. The hinge connection axes of the hinge connection points between these two inclined connecting rods 4 and the connector 1 were horizontal and perpendicular to the connection lines (i.e., diagonals) of the corresponding two diagonal corners of the two inclined connecting rods 4. The other ends of the inclined connecting rods 4 at the other two diagonal corners were hingedly connected to the clamp head 2. The hinge connection axes of the hinge connection points between these 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 diagonal corners of the two inclined connecting rods 4. The clamping opening of the clamp head 2 faced downward, and the back side of the clamping opening of the clamp head 2 was hingedly connected to the inclined connecting rods 4.

[0015] Operating 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 unidirectional 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 a tensile role, and cannot play a torsional role. Such a tensile tester has a lower purchase cost than a multi-axial fatigue tester, and the upper As the load head 5 moves upward, the connector 1 also moves upward, and the two inclined connecting rods 4 above the parallelogram structure consisting of the four horizontal connecting rods 3 deform the parallelogram structure consisting of the four horizontal connecting rods 3, and then pull the two inclined connecting rods 4 below the parallelogram structure, applying 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 deforms within that plane. During the deformation process, a rotation angle δα is generated, and a torsional force is transmitted to the test specimen 7, as shown in Figure 3, thereby achieving the purpose of combined tensile and torsional loading.

[0016] This tension-torsion loading device has a novel and simple structure, is compact, easy to install and disassemble, easy to use, and has low manufacturing costs. When combined with a conventional uniaxial tensile testing machine, it can achieve the purpose of multiaxial loading tests on materials and structures. The test specimen 7 can be cylindrical or sheet-shaped, and the shapes of commonly used test specimens 7 are shown in Figures 8 to 11. The material of the test specimen 7 is not limited to metal, but can also 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 (diagonals) of the two diagonals corresponding to these 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 diagonals) of the two diagonals corresponding to these 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, both the horizontal connecting rod 3 and the inclined connecting rod 4 were rectangular rods, as shown in Figures 1 to 11. Of course, square rods and rods of other shapes could also be used, but rectangular rods were 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 rigid rods, such as 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 clamping opening of the clamping 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. Furthermore, in this embodiment, as shown in Figures 1 to 11, the horizontal connecting rod 3 and the inclined connecting rod 4 are hingedly connected via a hinge sheet 8. 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, and the hinge connection axes of the first hinge head and the second hinge head are installed vertically. The first hinge head and the second hinge head are hingedly connected to one end of the two horizontal connecting rods 3. The third hinge head is perpendicular to the connection line between the first hinge head and the second hinge head, and the hinge connection axis of the third hinge head is installed horizontally. The third hinge head is hingedly 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 loading device of Example 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 loading device. This tensile tester is a unidirectional tensile device, meaning that 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. Therefore, this tensile tester can only perform a tensile function, not a torsional function. This tensile tester has a lower purchase cost than a multi-axial fatigue tester.

[0024] Operating principle: First, one end of the test specimen 7 is clamped to the lower load head 6 of the tensile tester, and the other end of the test specimen 7 is clamped to the clamp head 2. At this time, the four horizontal connecting rods 3 forming a parallelogram structure are positioned in the same horizontal plane. Next, 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 consisting of the four horizontal connecting rods 3 deform the parallelogram structure. Next, the two inclined connecting rods 4 below the parallelogram structure are pulled, applying an axial tensile load to the test specimen 7. At this time, the four horizontal connecting rods 3 are still positioned in the same horizontal plane, and the parallelogram structure deforms within its plane. During the deformation process, a rotation angle δα is generated. Therefore, a torsional force is transmitted to the test specimen 7, achieving the purpose of combined tensile and torsional loading, as shown in Figure 3.

[0025] This tensile-torsion load testing system consists of a tensile-torsion loading device and a conventional tensile testing machine. The main cost lies in the tensile testing machine. The manufacturing cost of the tensile-torsion loading device is almost negligible compared to the tensile testing machine. Because the tensile testing machine is a uniaxial testing machine, its purchase cost is significantly lower than that of a multiaxial loading testing machine. The test specimen 7 can be cylindrical or sheet-shaped. Figures 8 to 11 show commonly used shapes of test specimens 7. The material of the test specimen 7 is not limited to metal; it can also be a composite material.

[0026] The present invention uses specific examples to explain the principles and embodiments of the present invention, and the description of the above examples is only used to help understand the method and core idea of ​​the present invention. 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 heads 3 horizontal connecting rod 4 Inclined connecting rod 5 Upper Load Head 6 Lower Load Head 7 Test pieces 8 Hinge Seat

Claims

1. a tension-torsion loading device including a connector, a clamping head, and a connecting rod assembly, the connector being arranged to be clamped by an upper load head of a tensile tester, the clamping head being arranged to clamp one end of a test specimen, and the other end of the test specimen being 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, and 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 vertically, two of the four horizontal connecting rods are longer than the other two, and the four diagonal corners 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 hingedly connected to the connector, and 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 hingedly connected to the clamp head, and 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.

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

6. 1. A tension-torsion load testing system comprising: A tester including a tensile testing machine and the tensile-torsion 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.

Images