A tension-bending combined test device

Abstract

The present invention discloses a tension-bending combination test device, comprising a first chuck, a second chuck, a third chuck and a loading element. The second chuck and the third chuck fix two ends of a test sample. A tensile testing machine drives the first chuck and the second chuck to move relative to each other in a vertical direction for loading. Since the loading element is tilted relative to the vertical direction, the loading element is subjected to a force component along its tilt direction and a force component perpendicular to its tilt direction. The loading element deflects relative to the first chuck. Since the loading element is fixedly connected to the second chuck, the test sample is subjected to a bending force while being subjected to a tensile force, thereby achieving the simultaneous application of tensile and bending loads to the test sample, thereby conveniently performing a tension-bending combination test using a tensile testing machine. The tension-bending combination test device of the present invention has a simple and compact structure and is easy to operate, greatly reducing the test difficulty of tension-bending combination loading and saving the test cost of tension-bending combination loading.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical testing equipment and peripheral supporting facilities thereof, in particular to a tension-bending combined testing device. Background Art

[0002] Drones are of great significance in modern science and technology. In recent years, the rapid progress of drone technology and the expansion of its application areas have brought significant convenience and new opportunities to the development of all walks of life in society. The drone industry has broad prospects and huge development potential, and is an excellent representative of many emerging industries. Especially in the field of firefighting, drones have been widely used as an innovative technical means. Many domestic fire departments have successfully used drones for fire reconnaissance, on-site monitoring and rescue material delivery, and have achieved remarkable results.

[0003] The propeller blades of a drone are the key components of its flight. The drone generates lift and thrust by rotating during flight. Figure 1 As shown, the drone can take off, hover and fly. During operation, the blades will be subjected to inertial force due to high-speed rotation, which places high demands on their structural strength and service life. Therefore, accurate measurement of the force on the blade structure is crucial to ensure its performance.

[0004] When the firefighting drone performs firefighting tasks, the change in ambient temperature causes the propeller blades to not only bear inertial force, but also face stable loads (i.e. creep loads) caused by long-term high-temperature operation. Figure 2 As shown in the figure (the horizontal axis is time, the vertical axis is load), the blade structure is often under the action of complex loads related to time during service. This stress state will cause the blade structure to gradually deteriorate and be damaged as the working time of the blade structure increases, thereby reducing the operational stability and safety of the entire drone. Therefore, it is of great significance to the overall structural safety of the drone to conduct precise mechanical measurements of the drone propeller structure and clarify its strength and service life under complex loads.

[0005] At present, the service life of materials and structural parts under tensile and bending multi-axial loads is mostly carried out using a tensile-bending composite test system. The traditional tensile-bending combined test device can meet a variety of complex test requirements under static and dynamic loads of materials and structures, and can perform unidirectional tension, bending, and tensile-bending composite tests, but the equipment price is usually relatively high. The cost of purchasing a multi-axis hydraulic servo test machine is as high as 4 million yuan. The high price makes the engineering application field and related scientific research fields prohibitive, and to a certain extent limits the research of scientific researchers and engineers on the complex stress state of materials and structures. In addition, the multi-axis testing machine currently used has a complex structure, requires many installation fixtures, and the installation process is time-consuming. While the equipment price is high, it also brings many inconveniences to the experiment. Summary of the invention

[0006] The purpose of the present invention is to provide a tension-bending combination test device to solve the problems existing in the above-mentioned related technologies, simplify the structure of the tension-bending combination test device, improve the convenience of tension-bending combination test operation, and save test costs.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides a tension-bending combined test device, comprising:

[0009] First chuck;

[0010] A second chuck;

[0011] a third chuck, wherein the second chuck is located between the first chuck and the third chuck, the second chuck and the third chuck can clamp two ends of the test sample, the first chuck and the third chuck can both be connected to the main body of the tensile testing machine, and the tensile testing machine can drive the first chuck to move in a vertical direction relative to the third chuck;

[0012] A loading element, one end of which is rotatably connected to the first chuck, and the rotation axis is perpendicular to the vertical direction, the other end of which is connected to the second chuck, and the connection position between the loading element and the second chuck can be adjusted, and the loading element is tilted relative to the vertical direction.

[0013] Preferably, the loading element is rotatably connected to the first clamp by a hinge.

[0014] Preferably, one end of the loading element connected to the first chuck has a loading shaft, an external rotating sleeve of the loading shaft is provided with a loading sleeve, and the first chuck clamps and fixes the loading sleeve.

[0015] Preferably, the loading element is connected to the second clamping head by means of connecting bolts.

[0016] Preferably, the top of the second chuck has a connecting groove, the loading element can extend into the connecting groove, the second chuck has a plurality of mounting positions matching the connecting bolts, and the connecting bolts are assembled in different mounting positions to fix the loading elements with different inclination angles.

[0017] Preferably, the connecting bolt is threadedly connected to the second clamp to fix the relative position of the loading element and the second clamp.

[0018] Preferably, the loading element is a rod-shaped structure.

[0019] Preferably, the loading elements are provided in multiple groups, and the loading elements are detachably connected to the first chuck and the second chuck respectively.

[0020] Preferably, an electromagnetic chuck is disposed on the top of the second chuck, and the loading element is adsorbed and connected to the electromagnetic chuck.

[0021] Preferably, the tension-bending combination test device further comprises an environmental chamber, and the test specimen is located in the environmental chamber.

[0022] Compared with the related art, the present invention has achieved the following technical effects: the tension-bending combined test device of the present invention comprises a first chuck, a second chuck, a third chuck and a loading element, the second chuck is located between the first chuck and the third chuck, the second chuck and the third chuck can clamp both ends of the test sample, the first chuck and the third chuck can be connected to the main body of the tensile testing machine, and the tensile testing machine can drive the first chuck to move in the vertical direction relative to the third chuck; one end of the loading element is rotatably connected to the first chuck, and the rotation axis is perpendicular to the vertical direction, the other end of the loading element is connected to the second chuck, and the connection position of the loading element and the second chuck can be adjusted, and the loading element is inclined relative to the vertical direction.

[0023] In the tension-bending combination test device of the present invention, the second chuck and the third chuck fix the two ends of the test sample, and the tensile testing machine drives the first chuck and the second chuck to move relative to each other in the vertical direction for loading. Since the loading element is tilted relative to the vertical direction, the loading element is subjected to the component force along its tilt direction and the component force perpendicular to its tilt direction, and the loading element is deflected relative to the first chuck. Since the loading element is fixedly connected to the second chuck, the test sample is subjected to the bending force while being subjected to the tensile force, thereby achieving the simultaneous application of tensile and bending loads to the test sample, thereby conveniently performing the tension-bending combination test using the tensile testing machine. The tension-bending combination test device of the present invention has a simple and compact structure and is easy to operate, which greatly reduces the test difficulty of the tension-bending combination loading and saves the test cost of the tension-bending combination loading. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a schematic diagram of the force on the propeller blades of a drone;

[0026] Figure 2 This is the load diagram of the propeller blades of the UAV;

[0027] Figure 3 It is a structural schematic diagram of a tension-bending combination test device disclosed in an embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of the principle of the tension-bending combination test device disclosed in an embodiment of the present invention;

[0029] Figure 5 A side view schematic diagram of a second clamp of the tension-bending combination test device disclosed in an embodiment of the present invention;

[0030] Figure 6 It is a schematic top view of the second head and the loading element of the tension-bending combination test device disclosed in an embodiment of the present invention.

[0031] In the figure: 1. first chuck; 2. second chuck; 3. third chuck; 4. loading element; 5. test sample; 6. mounting position; 7. connecting groove; 8. connecting bolt; 9. tensile testing machine. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The purpose of the present invention is to provide a tension-bending combination test device to solve the problems existing in the above-mentioned related technologies, simplify the structure of the tension-bending combination test device, improve the convenience of tension-bending combination test operation, and save test costs.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Embodiment 1

[0036] This embodiment provides a tension-bending combined test device, please refer to Figure 3-Figure 6, including a first chuck 1, a second chuck 2, a third chuck 3 and a loading element 4, the second chuck 2 is located between the first chuck 1 and the third chuck 3, the second chuck 2 and the third chuck 3 can clamp the two ends of the test sample 5, the first chuck 1 and the third chuck 3 can be connected to the main body of the tensile testing machine 9, and the tensile testing machine 9 can drive the first chuck 1 to move in the vertical direction relative to the third chuck 3; one end of the loading element 4 is rotatably connected to the first chuck 1, and the rotation axis is perpendicular to the vertical direction, the other end of the loading element 4 is connected to the second chuck 2, and the connection position of the loading element 4 and the second chuck 2 can be adjusted, and the loading element 4 is inclined relative to the vertical direction.

[0037] In the tension-bending combination test device of the present invention, the second chuck 2 and the third chuck 3 fix the two ends of the test sample 5, and the tensile testing machine 9 drives the first chuck 1 and the second chuck 2 to move relative to each other in the vertical direction for loading. Since the loading element 4 is tilted relative to the vertical direction, the loading element 4 is subjected to the component force along its tilt direction and the component force perpendicular to its tilt direction, and the loading element 4 is deflected relative to the first chuck 1. Since the loading element 4 is fixedly connected to the second chuck 2, the test sample 5 is subjected to the bending force while being subjected to the tensile force, thereby achieving the simultaneous application of tensile and bending loads to the test sample 5, so that the tension-bending combination test is conveniently performed using the tensile testing machine 9. The tension-bending combination test device of the present invention has a simple and compact structure and is easy to operate, which greatly reduces the test difficulty of the tension-bending combination loading and saves the test cost of the tension-bending combination loading.

[0038] In this specific implementation, the loading element 4 is taken as a connecting rod structure for explanation. Figure 4 ,in F is the load applied by the tensile testing machine 9. When the initial position is F By decomposing it, we can get the tension along the connecting rod direction F B0 The force perpendicular to the connecting rod F W0 ,in F W0 That is, the bending force acting on the connecting rod. The relationship between the three is:

[0039] (1)

[0040] As the loading progresses, the position of the connecting rod rotates slightly and reaches the position after the load is applied. At this time, the force analysis of the connecting rod can obtain the tensile force along the connecting rod direction. F B1 The force perpendicular to the connecting rod F W1 ,in FW1 That is, the bending force acting on the connecting rod, and the three have the following relationship:

[0041] (2)

[0042] Combining formulas (1) and (2), we can get:

[0043] (3)

[0044] Formula (3) is the relationship between the initial position of the connecting rod and the force after the rotation angle θ occurs.

[0045] The loading element 4 adopts a connecting rod structure, which is simple in structure and can smoothly transmit the loading force to the test sample 5. In other specific embodiments of the present invention, the loading element 4 can also use other rigid structures. When the loading element 4 uses other rigid structures, the load applied by the tensile tester 9 is still decomposed along the direction of the connection line between the loading element 4 and the connection points between the first chuck 1 and the second chuck 2. It should be explained here that the deformation of the loading element 4 and the test sample 5 is small. When performing force analysis, the deformation of the loading element 4 can be ignored. Performing force analysis is a common method used by those skilled in the art and will not be repeated here.

[0046] In this specific embodiment, the loading element 4 can be rotatably connected to the first clamp 1 by a hinge to adapt to the deflection of the loading element 4 during loading, thereby improving the operational convenience of the tension-bending combination test.

[0047] In practical applications, in other specific embodiments that can be realized by the present invention, one end of the loading element 4 connected to the first chuck 1 has a loading shaft, the external rotating sleeve of the loading shaft is provided with a loading sleeve, and the first chuck 1 clamps and fixes the loading sleeve. During the loading process, when the loading element 4 deflects, the loading shaft rotates relative to the loading sleeve to avoid affecting the loading of the first chuck 1. It is also necessary to explain here that when the first chuck 1 and the third chuck 3 are connected to the main body of the tensile testing machine 9, the tensile testing machine 9 can drive one of the two to move to achieve the relative movement of the first chuck 1 and the third chuck 3 to achieve the loading purpose, and can also drive the first chuck 1 and the third chuck 3 to move for loading at the same time. The appropriate tensile testing machine 9 can be selected according to the specific test conditions to meet the test requirements.

[0048] Specifically, the loading element 4 is connected to the second clamp 2 by means of a connecting bolt 8 , and the connection is firm and the operation is convenient.

[0049] In this specific embodiment, the top of the second chuck 2 has a connection groove 7, and the loading element 4 can extend into the connection groove 7. The second chuck 2 has a plurality of mounting positions 6 that match the connection bolts 8. The connection bolts 8 are assembled in different mounting positions 6 to fix the loading elements 4 at different inclination angles. The connection bolts 8 are installed in different mounting positions 6 to fix the loading element 4, and the angle between the loading element 4 and the vertical direction can be adjusted to meet different loading test requirements and improve the flexibility, adaptability and ease of operation of the device.

[0050] It should be noted that the connecting bolt 8 is threadedly connected to the second clamp 2 to fix the relative position of the loading element 4 and the second clamp 2. Figure 5 and Figure 6 , the connecting groove 7 is a U-shaped groove with an opening at the top, and the mounting position 6 is arranged on the side of the connecting groove 7. When the loading element 4 extends into the connecting groove 7 at different positions, the angle of the loading element 4 with the vertical direction changes. When adjusted to a suitable loading angle, the connecting bolt 8 is threadedly connected to the second clamp 2 by the suitable mounting position 6, and extends into the connecting groove 7 to tighten the loading element 4, thereby realizing the connection between the loading element 4 and the second clamp 2. In other specific embodiments that can be realized by the present invention, the shape of the connecting groove 7 and the setting position of the mounting position 6 can be adjusted according to different working conditions, and the connecting bolt 8 can also be connected to the second clamp 2 and the loading element 4 at the same time to realize the connection between the second clamp 2 and the loading element 4. It should be explained here that when the inclination angle of the loading element 4 changes, the position of the first clamp 1 can be adjusted along the vertical direction to adapt to the angle change of the loading element 4.

[0051] In practical applications, multiple groups of loading elements 4 can be provided, and the loading elements 4 are detachably connected to the first chuck 1 and the second chuck 2 respectively. Different loading elements 4 can be replaced according to different test requirements to further improve the flexibility and adaptability of the device.

[0052] In other specific embodiments that can be realized by the present invention, an electromagnetic suction cup is provided on the top of the second chuck 2, and the loading element 4 is adsorbed and connected to the electromagnetic suction cup, which further facilitates the adjustment of the connection position of the loading element 4 and the second chuck 2 under the premise of ensuring that the connection between the loading element 4 and the second chuck 2 is stable. It is also necessary to explain here that when the line connecting the connection points of the loading element 4 and the first chuck 1 and the second chuck 2 is parallel to the vertical direction, bending loading cannot be achieved, so the loading element 4 is set to have an angle with the vertical direction to meet the combined tensile and bending loading.

[0053] In practical applications, the tension-bending combined test device of the present invention can also be provided with an environmental box, in which the test sample 5 is located, and the environmental box can be used to simulate vacuum, high temperature, low temperature and other environments to simulate the working environment of the test sample 5, thereby further improving the test accuracy. It should be explained here that when the test sample 5 is provided in the environmental box, the third chuck 3 can be provided for fixing, the second chuck 2 and the loading element 4 can be extended from the environmental box, the extended part is sealed, and the structure of the environmental box is reasonably provided to avoid affecting the deflection of the loading element 4, which is a common method used by those skilled in the art and will not be described in detail here.

[0054] Embodiment 2

[0055] This embodiment provides a tension-bending combination test system, including a tensile testing machine 9 and the tension-bending combination test device of the first embodiment.

[0056] The tension-bending combined test device of the present invention converts the resultant force of the test sample 5 in the tensile direction into a tensile force along the connecting rod and a bending force perpendicular to the connecting rod, and then applies a bending load, thereby achieving a longitudinal tensile load to achieve a tensile-bending loading method for the test sample 5. When the tension-bending combined test device of the present invention is applied to drone propeller blades, combined with an environmental chamber, it can simulate the stress state of the drone propeller blade structure under high temperature, low temperature and vacuum environments, providing a powerful reference for accurately evaluating its mechanical properties.

[0057] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A tension-bending combined test device, characterized in that: include: First chuck; A second chuck; a third chuck, wherein the second chuck is located between the first chuck and the third chuck, the second chuck and the third chuck can clamp two ends of the test sample, the first chuck and the third chuck can both be connected to the main body of the tensile testing machine, and the tensile testing machine can drive the first chuck to move in a vertical direction relative to the third chuck; A loading element, one end of which is rotatably connected to the first chuck, and the rotation axis is perpendicular to the vertical direction, the other end of which is connected to the second chuck, and the connection position of the loading element and the second chuck can be adjusted, and the loading element is tilted relative to the vertical direction; the loading element is connected to the second chuck by a connecting bolt; the top of the second chuck has a connecting groove, and the loading element can extend into the connecting groove, and the second chuck has a plurality of mounting positions matching the connecting bolts, and the connecting bolts are assembled in different mounting positions to fix the loading elements with different tilt angles; the connecting bolts are threadedly connected to the second chuck to fix the relative position of the loading element and the second chuck; and an environmental chamber is also included, and the test specimen is located in the environmental chamber.

2. The tension-bending combined test device according to claim 1, characterized in that: The loading element is rotatably connected to the first clamp by a hinge.

3. The tension-bending combined test device according to claim 1, characterized in that: One end of the loading element connected to the first chuck has a loading shaft, an external rotating sleeve of the loading shaft is provided with a loading sleeve, and the first chuck clamps and fixes the loading sleeve.

4. The tension-bending combined test device according to any one of claims 1 to 3, characterized in that: The loading element is a rod-shaped structure.

5. The tension-bending combined test device according to claim 1, characterized in that: The number of the loading elements is multiple groups, and the loading elements are detachably connected to the first chuck and the second chuck respectively.

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