A mechanical metamaterial bending wave test experimental device

Abstract

The invention discloses a mechanical metamaterial bending wave test experimental device, comprising a mechanical metamaterial specimen, a supporting device, a suspension device, a clamping device and a vibration source arm device; the supporting devices are all made of high-strength materials, including fixed ribs, vertical support columns, horizontal support columns and reinforcing ribs; the bottom of the vertical support column is fixedly installed in the experimental environment through the fixed ribs; the top of the vertical support column is equipped with a reinforcing rib, and two vertical support columns are provided, and the two ends of the horizontal support column are fixed to the top ends of the two vertical support columns through the reinforcing ribs; a "T"-shaped groove is provided on one side surface of the horizontal support column in the maximum length direction, and the suspension device is movably connected to the "T"-shaped groove to suspend and place the mechanical metamaterial specimen; the clamping device is installed on one side of the mechanical metamaterial specimen, one end of the vibration source arm device is connected to the clamping device, and the other end is connected to the experimental vibration source, and the clamping device and the vibration source arm device together serve as a conversion and transmission medium for the vibration source.

Description

Technical Field

[0001] The present invention relates to the technical field of artificial elastic wave metamaterials, and in particular to an experimental device with excellent performance for testing bending waves of mechanical metamaterials. Background Art

[0002] Long before the theory of elastic mechanics was used for stress analysis of structures and mechanical components, the theory of elastic wave propagation had been established. In recent years, mechanical metamaterials have extraordinary wave manipulation capabilities, allowing people to discover many new and research-worthy mechanical phenomena, which has attracted widespread attention. The characteristics of elastic wave and vibration propagation or bandgap characteristics of mechanical metamaterials make them have high application value and research prospects in disciplines or engineering fields such as mechanics, civil engineering and aerospace.

[0003] Experiments are an indispensable and important part of verifying the bending wave theory of mechanical metamaterials and exploring new phenomena. In recent years, there have been few reports on experimental devices for testing bending waves of mechanical metamaterials. The existing series of test benches are mostly focused on meeting the vibration measurement of rotor equipment and wave experiments under the influence of point vibration sources. The flexible, dedicated and efficient performance required for testing mechanical metamaterials under plane bending waves of linear vibration sources is not easy to meet. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide an experimental device for bending wave testing of mechanical metamaterials. The device has a simple structure and is easy to use. It can perform bending wave testing experiments on mechanical metamaterial specimens of different sizes and shapes and can achieve higher experimental accuracy.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A mechanical metamaterial bending wave test experimental device comprises a mechanical metamaterial specimen, and also comprises a supporting device, a suspension device, a clamping device and a vibration source arm device; the supporting devices are all made of high-strength materials, and comprise fixed ribs, vertical support columns, horizontal support columns and reinforcing ribs; the bottom of the vertical support column is fixedly mounted on a horizontal plane in an experimental environment through the fixed ribs; the top of the vertical support column is mounted with the reinforcing ribs, and two vertical support columns are provided, and the two ends of the horizontal support column are fixed to the top ends of the two vertical support columns through the reinforcing ribs; a "T"-shaped groove is arranged on one side surface of the horizontal support column in the maximum length direction, and the suspension device is movably connected to the "T"-shaped groove to suspend and place the mechanical metamaterial specimen; the clamping device is mounted on one side of the mechanical metamaterial specimen, one end of the vibration source arm device is connected to the clamping device, and the other end is connected to an experimental vibration source, and the clamping device and the vibration source arm device together serve as a conversion and transmission medium for the vibration source.

[0007] Furthermore, the suspension device includes a rolling wheel, a locking bolt and a thin rope. There are two rolling wheels, which are movably installed in the "T"-shaped groove. A threaded hole is opened between the central axis of the rolling wheel and the edge of the rolling wheel; the locking bolt is installed in the threaded hole, and the locking bolt is used to lock and release the rolling wheel; the central axis of the rolling wheel protrudes from the side surface of the horizontal support column, and the central axis of the rolling wheel is provided with a groove for installing the thin rope, which is used to suspend the mechanical metamaterial specimen and prevent the mechanical metamaterial specimen from contacting the supporting device.

[0008] Furthermore, the thin rope is made of nylon and can withstand a tensile force of more than 0.04t.

[0009] Furthermore, when the locking bolt is not tightened, the position of the scroll wheel can be adjusted according to the needs of different mechanical metamaterial experiments.

[0010] Furthermore, the clamping device includes a main clamping jaw, a secondary clamping jaw and a protective pad; the protective pad is made of rubber and has a thickness of 1.5 mm. Two protective pads are provided and are respectively installed at the clamping ends of the main clamping jaw and the secondary clamping jaw. The mechanical metamaterial specimen is placed between the protective pads of the main clamping jaw and the secondary clamping jaw, and the mechanical metamaterial specimen is clamped by a fastener. The protective pad is used to prevent the surface of the mechanical metamaterial specimen from being damaged;

[0011] Furthermore, the side of the protection pad in contact with the mechanical metamaterial specimen is printed with an anti-slip pattern; the auxiliary clamping jaw and the main clamping jaw are correspondingly provided with a row of connecting holes for clamping the mechanical metamaterial specimen by installing fasteners; the main clamping jaw is also provided with a row of vibration source holes for connecting to the vibration source arm device.

[0012] Furthermore, three connection holes are arranged on the auxiliary clamping jaw and the main clamping jaw at equal intervals; and nine vibration source holes are arranged.

[0013] Furthermore, the vibration source arm device includes a claw side part and a vibration source side part; the claw side part is tightly connected to the clamping device, one end of the vibration source side part is tightly connected to the claw side part, and the other end is connected to the experimental vibration source; the claw side part includes 3 groups of rods, each group of rods includes 1 A rod and two B rods; the vibration source side part includes 2 C rods and 1 A rod; the length relationship between the A rod, B rod and C rod is: the C rod is longer than the B rod, and the B rod is longer than the A rod.

[0014] Furthermore, the A rod in each group of rods on the claw side is horizontally arranged in the length direction, and the angle between the A rod in each group of rods and the two B rods in each group is 30°; the A rod in the vibration source side is horizontally arranged in the length direction, and the angle between the A rod in the vibration source side and the two C rods is 60°.

[0015] Furthermore, the length of the A rod is 138.56 mm, the length of the B rod is 160 mm, and the length of the C rod is 277.13 mm.

[0016] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0017] 1. This device solves the problem that the bending wave test experiment of mechanical metamaterials is not convenient to carry out on the traditional experimental platform; the parts used in the device are easy to process, the device cost is low and can be reused, which can save a lot of experimental costs.

[0018] 2. The device of the present invention adopts a mechanical metamaterial specimen placement method that cooperates with rolling wheels, locking bolts and high-strength thin ropes. The distance between the two rolling wheels can be adjusted and whether to lock can be selected without disassembling the device or replacing parts. It is flexibly applicable to mechanical metamaterial specimens of different sizes and different experimental scenarios. At the same time, the method of suspending the mechanical metamaterial specimen with high-strength thin ropes makes the bending wave energy transmission less attenuated by external factors, which can make the specific frequency change experiment easier to achieve.

[0019] 3. The device of the present invention adopts a combination of vibration source transmission rods with a tree-like distribution, and finally generates plane bending waves on the mechanical metamaterial specimen through a specific combination of the number and arrangement of rods of different lengths. This process realizes the transformation from a point vibration source to a corresponding linear vibration source, as well as the high-efficiency characteristics of vibration source transmission.

[0020] 4. The clamping device and the vibration source arm device of the device of the present invention pass through during the experimental vibration source transmission process, and the internal components are rigidly connected, thereby achieving the goals of stable device, low energy loss and little interference with experimental results. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the three-dimensional structure of a mechanical metamaterial bending wave testing experimental device provided in an embodiment of the present invention.

[0022] Figure 2 It is a schematic diagram of the explosion structure of the actual configuration of the bending wave test experimental device in an embodiment of the present invention.

[0023] Figure 3 Schematic diagram of the explosion structure of the suspension device in an embodiment of the present invention.

[0024] Figure 4 Detailed schematic diagram of the horizontal support column in an embodiment of the present invention.

[0025] Figure 5 Schematic diagram of cross-sectional details of a horizontal support column in an embodiment of the present invention.

[0026] Figure 6 Schematic diagram of the exploded structure of the clamping device in the embodiment of the present invention.

[0027] Figure 7 Schematic diagram of the explosion structure of the vibration source part in the vibration source arm device in an embodiment of the present invention.

[0028] Figure numerals: 1-fixed rib, 2-vertical support column, 3-reinforced rib, 4-horizontal support column, 5-rolling wheel, 6-thin rope, 7-locking bolt, 8-mechanical metamaterial specimen, 9-protection pad, 10-secondary clamp, 11-main clamp, 12-tightening bolt, 13-tightening nut, 14-C rod, 15-A rod, 16-B long rod DETAILED DESCRIPTION

[0029] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0030] A scheme adopted by a mechanical metamaterial bending wave test experimental device in an embodiment of the present invention is: when conducting a mechanical metamaterial elastic wave experiment, the vibration source arm device and the clamping device in the embodiment of the present invention cooperate to convert a point vibration source in the form of a sine wave or the like emitted by the vibration source motor into a linear vibration source, and transmit it to the mechanical metamaterial specimen suspended in the high-strength thin rope in the embodiment of the present invention through the clamping device in the embodiment of the present invention. During the experiment, the supporting device in the embodiment of the present invention provides structural support; the locking bolts of the suspension device in the embodiment of the present invention are processed and used to cooperate with the rolling wheel to achieve position locking. In addition, although bolts are contained in other positions of the device, they are only used as device materials to keep the corresponding rigid components tightly connected, and are not used as the vibration source propagation method and experimental device architecture body required for the mechanical metamaterial experiment.

[0031] The structure of a mechanical metamaterial bending wave test experimental device provided by an embodiment of the present invention is as follows: Figure 1 and Figure 2As shown, it includes a supporting device, a suspension device, a clamping device and a vibration source arm device: the supporting device includes a fixed rib plate 1, a vertical supporting column 2, a reinforcing rib plate 3, and a horizontal supporting column 4, and each component is made of high-strength materials; the vertical supporting column 2 is bolted to the fixed rib plate 1, and the lower surface of the vertical supporting column 2 and the lower surface of the fixed rib plate 1 are on the same plane. By installing the fixed rib plate 1 on a horizontal plane, the vertical fixation in the experimental environment is achieved; both ends of the horizontal supporting column 4 are fixed to the vertical supporting column 1 through the reinforcing rib plate 3, and the horizontal supporting column 4 is processed with a groove with a "T"-shaped cross-section in the length direction, and the "T"-shaped groove structure is as shown in Figure 4 and Figure 5 As shown; the suspension device is connected to the "T"-shaped groove of the horizontal support column 4 to suspend and place the mechanical metamaterial specimen 8; the clamping device is installed at one end of the mechanical metamaterial specimen 8; the vibration source arm device is installed on the clamping device, and together they serve as a vibration source conversion and transmission medium.

[0032] Suspension device such as Figure 3 As shown, it includes a rolling wheel 5, a thin rope 6, and a locking bolt 7; there are two rolling wheels 5, both of which are installed in the "T"-shaped groove of the horizontal support column 4, and a threaded hole is opened between the central axis and the wheel edge; the locking bolt 7 is installed in the threaded hole of the rolling wheel 5, and the position of the rolling wheel 5 can be locked by utilizing the friction between the rolling wheel 5 and the horizontal support column 4 when tightened; the thin rope 6 is made of nylon and other materials, and is installed in the groove opened on the central axis of the rolling wheel 5, so that the mechanical metamaterial specimen 8 can be suspended to avoid contact with the vertical support column 2 or the horizontal support column 4; when the locking bolt 7 is tightened, the position of the rolling wheel 5 can be locked; when the locking bolt 7 is not tightened, the position of the rolling wheel 5 can be adjusted; whether the position of the rolling wheel 5 is locked or not can be adjusted according to the needs of different mechanical metamaterial experiments.

[0033] Clamping device such as Figure 6 As shown, it includes a protective pad 9, a secondary clamping claw 10, and a main clamping claw 11. The protective pad 9 is made of rubber with a thickness of 1.5 mm. At the same time, an anti-slip pattern is printed on the side in contact with the mechanical metamaterial specimen 8, and is installed on the secondary clamping claw 10 and the main clamping claw 11 respectively; the secondary clamping claw 10 has a row of 3 through holes in the maximum length direction; the main clamping claw 11 has two rows of through holes in the maximum length direction, one row has 3 through holes for matching with the secondary clamping claw 10, and the other row has 9 through holes for connecting with the vibration source arm device; when the mechanical metamaterial specimen 8 is placed between the secondary clamping claw 10 and the main clamping claw 11, the matching tightening bolts 12 and tightening nuts 13 in the through holes of the secondary clamping claw 10 and the main clamping claw 11 are tightened to clamp the mechanical metamaterial specimen 8, and the protective pad 9 should prevent the surface of the mechanical metamaterial specimen 8 from being clamped.

[0034] Vibration arm device Figure 7As shown, it includes two parts, the claw side and the vibration source side; the claw side part includes three groups of 9 rods in total, with 3 rods in each group; each group includes one A rod 15 with a length of 138.56 mm and two B rods 16 with a length of 160 mm;

[0035] The vibration source side part includes two 277.13 mm long C rods 14 and one 138.56 mm long A rod 15; the claw side part is fastened to the main claw 11 by bolts, and the A rod 15 in each group is horizontal in the length direction, and forms a 30° angle with the two B rods 16; one end of the vibration source side part is fastened to the claw side part by bolts, and the other end is connected to the experimental vibration source; in the vibration source side part, the A rod 15 is horizontal in the length direction, and forms a 60° angle with the two C rods 14.

[0036] In this embodiment, a specific combination of the number and arrangement of the three different lengths of rods, namely the 138.56 mm long A rod 15, the 160 mm long B rod 16 and the 277.13 mm long C rod 14, cooperates with the clamping device to realize the conversion of the point vibration source emitted by the vibration source motor into a linear vibration source and finally transmit it to the mechanical metamaterial specimen, thereby generating a plane bending wave.

[0037] The device and system embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without creative work.

[0038] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or coupling. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items.

[0039] The present invention is not limited to the embodiments described above. The above description of the specific embodiments is intended to describe and illustrate the technical solution of the present invention. The above specific embodiments are merely illustrative and not restrictive. Without departing from the scope of the present invention and the scope of protection of the claims, a person of ordinary skill in the art can also make many forms of specific changes under the guidance of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A mechanical metamaterial bending wave test experimental device, comprising a mechanical metamaterial specimen, characterized in that: It also includes a supporting device, a suspension device, a clamping device and a vibration source arm device; the supporting device includes a fixed rib plate, a vertical supporting column, a horizontal supporting column and a reinforcing rib plate; the bottom of the vertical supporting column is fixedly installed on a horizontal plane in the experimental environment through the fixed rib plate; the reinforcing rib plate is installed on the top of the vertical supporting column, and two vertical supporting columns are provided, and the two ends of the horizontal supporting column are fixed to the top ends of the two vertical supporting columns through the reinforcing rib plates; a "T"-shaped groove is provided on one side surface of the horizontal supporting column in the maximum length direction, and the suspension device is movably connected to the "T"-shaped groove to suspend and place the mechanical metamaterial specimen; The clamping device is installed on one side of the mechanical metamaterial specimen, one end of the vibration source arm device is connected to the clamping device, and the other end is connected to the experimental vibration source, and the clamping device and the vibration source arm device together serve as a conversion and transmission medium for the vibration source; The vibration source arm device includes a claw side part and a vibration source side part; the claw side part is tightly connected to the clamping device, one end of the vibration source side part is tightly connected to the claw side part, and the other end is connected to the experimental vibration source; the claw side part includes 3 groups of rods, each group of rods includes 1 A rod and two B rods; the vibration source side part includes 2 C rods and 1 A rod; the length relationship between the A rod, B rod and C rod is: the C rod is longer than the B rod, and the B rod is longer than the A rod.

2. According to claim 1, a mechanical metamaterial bending wave test experimental device is characterized in that: The suspension device includes a rolling wheel, a locking bolt and a thin rope. There are two rolling wheels, both of which are movably installed in the "T"-shaped groove. A threaded hole is opened between the central axis of the rolling wheel and the edge of the rolling wheel; the locking bolt is installed in the threaded hole, and the locking bolt is used to lock and release the rolling wheel; the central axis of the rolling wheel protrudes from the side surface of the horizontal support column, and the central axis of the rolling wheel is provided with a groove for installing the thin rope, which is used to suspend the mechanical metamaterial specimen and prevent the mechanical metamaterial specimen from contacting the supporting device.

3. According to claim 2, a mechanical metamaterial bending wave test experimental device is characterized in that: The thin rope is made of nylon and can withstand a pulling force of more than 0.04t.

4. According to claim 2, a mechanical metamaterial bending wave test experimental device is characterized in that: When the locking bolt is not tightened, the position of the rolling wheel can be adjusted according to the needs of different mechanical metamaterial experiments.

5. According to claim 1, a mechanical metamaterial bending wave test experimental device is characterized in that: The clamping device includes a main clamping jaw, a secondary clamping jaw and a protective pad; the protective pad is made of rubber and has a thickness of 1.5 mm. Two protective pads are provided and are respectively installed at the clamping ends of the main clamping jaw and the secondary clamping jaw. The mechanical metamaterial specimen is placed between the protective pads of the main clamping jaw and the secondary clamping jaw, and the mechanical metamaterial specimen is clamped by a fastener. The protective pad is used to prevent the surface of the mechanical metamaterial specimen from being damaged.

6. According to claim 5, a mechanical metamaterial bending wave test experimental device is characterized in that: The side of the protection pad in contact with the mechanical metamaterial specimen is printed with anti-slip patterns; the auxiliary clamping jaw and the main clamping jaw are correspondingly provided with a row of connecting holes for clamping the mechanical metamaterial specimen by installing fasteners; the main clamping jaw is also provided with a row of vibration source holes for connecting to the vibration source arm device.

7. The mechanical metamaterial bending wave test experimental device according to claim 6, characterized in that: There are three connection holes on the auxiliary clamping claw and the main clamping claw at equal intervals; there are nine vibration source holes.

8. The mechanical metamaterial bending wave test experimental device according to claim 1, characterized in that: The A rod in each group of rods on the claw side is arranged horizontally in the length direction, and the angle between the A rod in each group of rods and the two B rods in each group is 30°; the A rod in the vibration source side is arranged horizontally in the length direction, and the angle between the A rod in the vibration source side and the two C rods is 60°.

9. A mechanical metamaterial bending wave test experimental device according to claim 1 or 8, characterized in that: The length of the A rod is 138.56 mm, the length of the B rod is 160 mm, and the length of the C rod is 277.13 mm.

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