Axial folding mechanism and band gap adjustable photonic crystal vibration damper

Abstract

The invention discloses an axial folding mechanism and a band-gap-adjustable photonic crystal vibration reduction device, and belongs to the technical field of photonic crystal vibration reduction. The axial folding mechanism comprises a plurality of folding plates, a plurality of hinges and a plurality of spherical hinges, wherein the folding plates are connected together through the hinges and the spherical hinges. The plurality of folding plates are assembled in a Mipu paper folding stacking structure, adjacent sides of two adjacent folding plates are connected through hinges, and contact points of three adjacent folding plates are connected through spherical hinges; folding plate electromagnets are arranged on the folding plates located at the two ends of the axial paper folding mechanism, and the two folding plate electromagnets are connected with a power source. The photonic crystal vibration damper with the adjustable band gap comprises a plurality of sleeves, and the sleeves are used for regularly sleeving a tubular target structure at intervals; a plurality of axial folding mechanisms are arranged between the two sleeves in the axial direction of the sleeves. The device is convenient to design and manufacture, the mounting distance of the photonic crystal vibration reduction units can be changed through remote and reversible electromagnetic driving, so that the band gap adjustable effect is achieved, and operation is easy and convenient.

Description

Technical Field

[0001] The invention belongs to the technical field of phononic crystal vibration reduction, and relates to an axial folding mechanism and a phononic crystal vibration reduction device with adjustable band gap. Background Art

[0002] The performance of phononic crystals is highly dependent on their sophisticated periodic structural design, which usually requires designers to have deep multidisciplinary knowledge in materials science, solid mechanics, acoustics, etc. In order to obtain ideal band gap characteristics, designers need to precisely control multiple parameters such as lattice constant, scatterer shape, arrangement, and filling rate. Slight changes in these parameters may have a significant impact on the width, position, and shape of the band gap. Therefore, the design process often requires a lot of numerical simulations and experimental verification to ensure the accuracy and effectiveness of the design. In addition, in order to meet the specific needs of different application scenarios, the structure of phononic crystals must also have sufficient flexibility and adjustability, which undoubtedly further increases the complexity and difficulty of the design.

[0003] Although bandgap-adjustable phononic crystals have shown great potential and application prospects in the field of vibration and noise reduction, their current development still faces some challenges, the most notable of which are the complexity of structural design and the difficulty of bandgap adjustment. These problems not only limit the widespread promotion of phononic crystals in practical applications, but also put forward higher requirements for the optimization and customized design of their performance. Although bandgap-adjustable phononic crystals can theoretically dynamically adjust the bandgap by changing structural parameters or material properties, they face many challenges in actual operation. On the one hand, it is often impractical to directly change the physical size or shape of the manufactured phononic crystal structure, which not only requires high-precision processing technology, but may also cause irreversible damage to the structure itself. On the other hand, adjusting the bandgap by changing the material properties, such as using external stimuli such as temperature, pressure or electric field to change the elastic modulus or density of the material, although it is theoretically feasible, in practical applications it requires complex control systems and precise control strategies to ensure the accuracy and stability of the adjustment. In addition, these external stimuli may also affect other properties of phononic crystals, such as thermal stability, mechanical strength, etc., thereby limiting their scope of application. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problems in the prior art that phononic crystals generally have complex structural designs and are difficult to operate when adjusting the band gap, and to provide an axial folding mechanism and a phononic crystal vibration reduction device with adjustable band gap.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: In the first aspect, the present invention provides an axial folding mechanism, comprising a plurality of folding plates and a plurality of hinges and ball joints connecting each folding plate together; the plurality of folding plates are assembled in a Miura origami stacking structure, the adjacent edges of two adjacent folding plates are connected by hinges, and the contact points of three adjacent folding plates are connected by ball joints; folding plate electromagnets are provided on the folding plates at both ends of the axial origami mechanism, and the two folding plate electromagnets are connected to a power source.

[0006] Further improvements are: The power source connected to the folding plate electromagnet is a DC power source.

[0007] The material of the folding plate is plastic.

[0008] In the second aspect, the present invention provides a phononic crystal vibration reduction device with adjustable band gap using the above-mentioned axial folding mechanism, comprising a plurality of sleeves, wherein the plurality of sleeves are used to be regularly spaced on a tubular target structure; a plurality of axial folding mechanisms are arranged between the two sleeves around the axial direction of the sleeve; the sleeves and the tubular target structure are both clearance-fitted.

[0009] Further improvements are: The sleeve comprises two semicircular ring structures connected by hinges on one side, and electromagnets are arranged on the mating surfaces on the other sides of the two semicircular ring structures; the two electromagnets are respectively connected to power sources.

[0010] The power source connected to the electromagnet is a DC power source.

[0011] The outer side angle of the sleeve is less than 360°.

[0012] The several axial folding mechanisms arranged between the two sleeves around the axis of the sleeve constitute a group of axial folding mechanisms; the group of axial folding mechanisms includes at least two axial folding mechanisms and are evenly arranged around the axis of the sleeve, and the folding plate electromagnets located at the same end in the group of axial folding mechanisms are connected in series and connected to the same power supply.

[0013] The set of axial folding mechanisms includes two axial folding mechanisms and is symmetrically arranged around the axis of the sleeve.

[0014] At least one set of axial folding mechanisms is arranged between the two sleeves along the axis.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses an axial folding mechanism, wherein a plurality of folding plates are assembled in a Miura origami stacking structure, the adjacent sides of two adjacent folding plates are connected by hinges, the contact points of three adjacent folding plates are connected by ball joints, and folding plate electromagnets are arranged on the folding plates at both ends of the axial folding mechanism, and both folding plate electromagnets are connected to a power source. When in use, the folding plate electromagnets on the axial folding mechanism are energized to generate magnetic force on the folding plate electromagnets at both ends of the axial folding mechanism, so that the two folding plate electromagnets on the same axial folding mechanism attract or repel each other, so that the axial folding mechanism is extended and retracted, and the distance between the two axial folding mechanisms can be freely adjusted by changing the size and direction of the current. The Miura origami stacking structure can form a variety of structures such as rhombus, triangle, windmill, parallelogram, etc., so that the structure can maintain a certain rigidity and stability when unfolding and folding.

[0016] The present invention discloses a phononic crystal vibration reduction device with adjustable band gap using the above-mentioned axial folding mechanism, comprising a plurality of sleeves, wherein the plurality of sleeves are used to be regularly sleeved on a tubular target structure, and a plurality of axial folding mechanisms are arranged between two sleeves around the axial direction of the sleeves, and the sleeves and the tubular target structure are both clearance-matched. When in use, the folding plate electromagnets on the axial folding mechanism are energized to make the folding plate electromagnets at both ends of the axial folding mechanism generate magnetic force, so that the two folding plate electromagnets on the same axial folding mechanism attract or repel each other, so that the axial folding mechanism is extended and retracted, and the spacing between the sleeves can be changed by changing the size and direction of the input current, and the spacing between the sleeves can be freely adjusted by changing the size and direction of the input current. After determining the spacing between the casing units, the current input to the electromagnet on the casing is strengthened to enhance the magnetic field force of attraction between the two electromagnets on the casing, thereby completely locking the casing, and then strengthening the contact stiffness between the casing and the tubular target structure, and generating a step increase in the structural bending stiffness within the casing covering section; in this way, by installing a sequence of vibration reduction units at equal intervals on the tubular target structure, the original tubular target structure is transformed into a phononic crystal structure, thereby generating a bending wave band gap, preventing the bending wave from propagating within the tubular target structure, so as to achieve a vibration reduction effect, and the introduction of the axial folding mechanism can change the installation spacing of the casing through remote and reversible electromagnetic drive, thereby achieving an adjustable band gap effect. The present invention is easy to design and manufacture, and can change the installation spacing of the phononic crystal vibration reduction unit through remote and reversible electromagnetic drive, thereby achieving an adjustable band gap effect, and is easy to operate.

[0017] Furthermore, a plurality of axial folding mechanisms arranged around the axis of the sleeve between the two sleeves form a group of axial folding mechanisms. A group of axial folding mechanisms includes at least two axial folding mechanisms and are evenly arranged around the axis of the sleeve. The folding plate electromagnets located at the same end of a group of axial folding mechanisms are connected in series and connected to the same power supply to ensure that the magnetic field force generated by the folding plate electromagnets on the same side is the same in magnitude and direction, thereby realizing coordinated axial movement of the sleeve.

[0018] Furthermore, at least one set of axial folding mechanisms is arranged between the two sleeves along the axis, and multiple sets of axial folding mechanism units can be installed axially to increase the range of the sleeve installation spacing, thereby increasing the adjustment range of the bending wave band gap frequency and achieving vibration reduction in a wider range of target frequencies. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a structural schematic diagram of an axial folding mechanism in the present invention; Figure 2 It is a schematic diagram of the sleeve structure in a phononic crystal vibration reduction device with adjustable band gap in the present invention; Figure 3 The figure is a schematic diagram of the working structure of a phononic crystal vibration reduction device with adjustable band gap in the present invention.

[0021] Among them: 1- casing; 2- tubular target structure; 3- folding plate; 4- electromagnet; 5- hinge; 6- ball joint; 7- hub; 8- wire; 9- power supply. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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.

[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0025] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0026] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0027] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings: See also Figure 1The present invention discloses an axial folding mechanism, comprising a plurality of folding plates 3 and a plurality of hinges 31 and ball joints 5 connecting each folding plate 3 together; the material of the folding plates 3 is plastic. The plurality of folding plates 3 are assembled in a Miura origami stacking structure, the adjacent edges of two adjacent folding plates 3 are connected by hinges 31, and the contact points of three adjacent folding plates 3 are connected by ball joints 5; folding plate electromagnets are arranged on the folding plates 3 at both ends of the axial folding mechanism, and the two folding plate electromagnets are connected to a power source, and the power source connected to the folding plate electromagnets is a DC power source. The present invention discloses an axial folding mechanism, wherein a plurality of folding plates are assembled in a Miura origami stacking structure, the adjacent sides of two adjacent folding plates are connected by hinges, the contact points of three adjacent folding plates are connected by ball joints, and folding plate electromagnets are arranged on the folding plates at both ends of the axial folding mechanism, and both folding plate electromagnets are connected to a power source. When in use, the folding plate electromagnets on the axial folding mechanism are energized to generate magnetic force on the folding plate electromagnets at both ends of the axial folding mechanism, so that the two folding plate electromagnets on the same axial folding mechanism attract or repel each other, so that the axial folding mechanism is extended and retracted, and the distance between the two axial folding mechanisms can be freely adjusted by changing the size and direction of the current. The Miura origami stacking structure can form a variety of structures such as rhombus, triangle, windmill, parallelogram, etc., so that the structure can maintain a certain rigidity and stability when unfolding and folding.

[0029] See also Figure 2 and Figure 3The present invention discloses a bandgap adjustable phononic crystal vibration reduction device using the above-mentioned axial folding mechanism, comprising a plurality of sleeves 1, the plurality of sleeves 1 being used to be regularly spaced on a tubular target structure 2; a plurality of axial folding mechanisms are arranged between the two sleeves 1 around the axial direction of the sleeve 1; the sleeve 1 and the tubular target structure 2 are both clearance-matched. The sleeve 1 comprises two semicircular ring structures connected by a hinge 31 on one side, and electromagnets 4 are arranged on the mating surfaces on the other side of the two semicircular ring structures; the two electromagnets 4 are respectively connected to a power source. The power source connected to the electromagnet 4 is a DC power source. The outer angle of the sleeve 1 is less than 360°. The inner wall of the sleeve is made to fit tightly with the tubular target structure. The several axial folding mechanisms arranged around the axis of the sleeve 1 between the two sleeves 1 are a group of axial folding mechanisms; the group of axial folding mechanisms includes at least two axial folding mechanisms and are evenly arranged around the axis of the sleeve 1. The folding plate electromagnets at the same end of the group of axial folding mechanisms are connected in series and connected to the same power supply to ensure that the magnetic field force generated by the folding plate electromagnets on the same side is of the same magnitude and direction, thereby achieving coordinated axial movement of the sleeve. The group of axial folding mechanisms includes two axial folding mechanisms and are symmetrically arranged around the axis of the sleeve 1. At least one group of axial folding mechanisms is arranged along the axis between the two sleeves 1, and multiple groups of axial folding mechanism units can also be installed in the axial direction to increase the range of the sleeve installation spacing, thereby increasing the adjustment range of the bending wave band gap frequency and achieving vibration reduction of a wider range of target frequencies.

[0030] The present invention discloses a phononic crystal vibration reduction device with adjustable band gap using the above-mentioned axial folding mechanism, comprising a plurality of sleeves, wherein the plurality of sleeves are used to be regularly sleeved on a tubular target structure, and a plurality of axial folding mechanisms are arranged between two sleeves around the axial direction of the sleeves, and the sleeves and the tubular target structure are both clearance-matched. When in use, the folding plate electromagnets on the axial folding mechanism are energized to make the folding plate electromagnets at both ends of the axial folding mechanism generate magnetic force, so that the two folding plate electromagnets on the same axial folding mechanism attract or repel each other, so that the axial folding mechanism is extended and retracted, and the spacing between the sleeves can be changed by changing the size and direction of the input current, and the spacing between the sleeves can be freely adjusted by changing the size and direction of the input current. After determining the spacing between the casing units, the current input to the electromagnet on the casing is strengthened to enhance the magnetic field force of attraction between the two electromagnets on the casing, thereby completely locking the casing, and then strengthening the contact stiffness between the casing and the tubular target structure, and generating a step increase in the structural bending stiffness within the casing covering section; in this way, by installing a sequence of vibration reduction units at equal intervals on the tubular target structure, the original tubular target structure is transformed into a phononic crystal structure, thereby generating a bending wave band gap, preventing the bending wave from propagating within the tubular target structure, so as to achieve a vibration reduction effect, and the introduction of the axial folding mechanism can change the installation spacing of the casing through remote and reversible electromagnetic drive, thereby achieving an adjustable band gap effect. The present invention is easy to design and manufacture, and can change the installation spacing of the phononic crystal vibration reduction unit through remote and reversible electromagnetic drive, thereby achieving an adjustable band gap effect, and is easy to operate.

[0031] The working principle of the present invention is as follows: When the vibration reduction device of the present invention is installed on a target tubular structure to form a phonon transistor, the eigenvalue problem of the overall structure can be expressed as:

[0032] Where: ω is the vibration frequency, U is the displacement vector of the overall structure, K bp is the stiffness matrix of the target tubular structure, M bp is the mass matrix of the target tubular structure, K as The additional stiffness matrix generated by installing this vibration reduction unit, M as The additional mass matrix generated for installing this vibration reduction unit.

[0033] Take a metal tube as an example, assuming that its inner diameter is 4mm, outer diameter is 5mm, Young's modulus is 160GPa, Poisson's ratio is 0.3, density is 7617kg / m3, and the metal tube is equally spaced to install a sleeve of the same material with a length of 80mm, inner diameter of 5mm, and outer diameter of 10mm. Using the above formula, it can be calculated that when the center spacing of the sleeve is 100mm, a bending wave band gap with a frequency range of 1380Hz-2730Hz and a bandwidth of 1350Hz can be formed in the overall structure; when the center spacing of the sleeve is 140mm, a bending wave band gap with a frequency range of 769Hz-976Hz and a bandwidth of 207Hz can be formed in the overall structure.

[0034] The working process of the present invention is as follows: like Figure 2 As shown, a bandgap-adjustable phononic crystal vibration reduction method based on axial folding action is provided. Each group of phononic crystal vibration reduction units includes two semicircular sleeves 1, an electromagnet 4, and a hinge 31. The hinge 31 is arranged at an opening at one end of the sleeve 1 and is used to connect one end of the two sleeves 1. Two electromagnets 4 are bonded to both sides of the inner wall of the section of the sleeve 1 at the other side of the opening relative to the hinge 31. During installation, the two sleeves 1 are first interlocked on the tubular target structure 2. When the positive and negative ends of the circuit are connected to the hub 8 and energized, each pair of electromagnets 4 will generate a magnetic field force of attraction, so that the sleeve 1 is installed on the tubular target structure 2 without falling off. At this time, a step-up improvement in the structural quality is generated within the covering section of the sleeve 1. like Figure 1 and Figure 3 As shown, the axial folding mechanism unit includes a plurality of plastic plates 3, hinges 31, and ball joints 5. The axial folding mechanism is assembled in the stacking form of Miura Origami, wherein the plastic plates 3 are connected to the ball joints 5 through hinges 31. Folding plate electromagnets are connected at both ends of the axial folding mechanism. When in use, the folding plate electromagnets on the axial folding mechanism are energized to generate magnetic field forces of attraction or repulsion between the folding plate electromagnets at both ends of the axial folding mechanism, thereby causing the axial folding mechanism to expand and contract, thereby changing the spacing of the sleeves 1. The spacing of the sleeves 1 can be freely adjusted by changing the magnitude and direction of the current passed into the folding plate electromagnets on the axial folding mechanism. After determining the spacing of the casing 1 units, the current input in the electromagnet 4 on the casing 1 is strengthened to completely lock the casing 1, thereby strengthening the contact stiffness between the casing 1 and the tubular target structure 2, and generating a step increase in the structural bending stiffness within the casing coverage section; in this way, by installing a sequence of vibration reduction units at equal intervals on the tubular target structure 2, the original tubular target structure 2 is transformed into a phononic crystal structure, thereby generating a bending wave band gap, preventing the bending wave from propagating in the tubular target structure 2, so as to achieve a vibration reduction effect, and the introduction of the axial folding mechanism unit can change the installation spacing of the phononic crystal vibration reduction unit by a remote and reversible driving method, thereby achieving an adjustable band gap effect.

[0035] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An axial folding mechanism, characterized in that: The invention comprises a plurality of folding plates (3) and a plurality of hinges (31) and ball joints (5) for connecting each folding plate (3) together; the plurality of folding plates (3) are assembled in a Miura origami stacking structure, the adjacent edges of two adjacent folding plates (3) are connected by hinges (31), and the contact points of three adjacent folding plates (3) are connected by ball joints (5); the folding plates (3) at both ends of the axial origami mechanism are provided with folding plate electromagnets, and the two folding plate electromagnets are connected to a power source.

2. The axial folding mechanism according to claim 1, characterized in that: The power source connected to the folding plate electromagnet is a DC power source.

3. The axial folding mechanism according to claim 1, characterized in that: The material of the folding plate (3) is plastic.

4. A phononic crystal vibration reduction device with adjustable band gap using the axial folding mechanism according to claims 1-3, characterized in that: The invention comprises a plurality of sleeves (1), wherein the plurality of sleeves (1) are used to be sleeved on a tubular target structure (2) at regular intervals; a plurality of axial folding mechanisms are arranged axially around the sleeves (1) between the two sleeves (1); and the sleeves (1) and the tubular target structure (2) are both clearance-fitted.

5. The bandgap adjustable phononic crystal vibration reduction device according to claim 4, characterized in that: The sleeve (1) comprises two semi-circular ring structures connected by a hinge (31) on one side, and electromagnets (4) are provided on the mating surfaces on the other sides of the two semi-circular ring structures; the two electromagnets (4) are respectively connected to a power source.

6. The bandgap adjustable phononic crystal vibration reduction device according to claim 4, characterized in that: The power source connected to the electromagnet (4) is a direct current power source.

7. The bandgap adjustable phononic crystal vibration reduction device according to claim 4, characterized in that: The outer side angle of the sleeve (1) is less than 360°.

8. The bandgap adjustable phononic crystal vibration reduction device according to claim 4, characterized in that: The plurality of axial folding mechanisms arranged between the two sleeves (1) around the axis of the sleeve (1) constitute a group of axial folding mechanisms; the group of axial folding mechanisms comprises at least two axial folding mechanisms and are evenly arranged around the axis of the sleeve (1); the folding plate electromagnets located at the same end of the group of axial folding mechanisms are connected in series and then connected to the same power supply.

9. The bandgap adjustable phononic crystal vibration reduction device according to claim 8, characterized in that: The set of axial folding mechanisms comprises two axial folding mechanisms and is symmetrically arranged around the axis of the sleeve (1).

10. The bandgap adjustable phononic crystal vibration reduction device according to claim 8, characterized in that: At least one set of axial folding mechanisms is arranged between the two sleeves (1) along the axis.

Images