Phononic crystal with broadband elastic wave control and band gap active adjustment functions

Abstract

The invention discloses a photonic crystal with broadband elastic wave control and band gap active adjustment functions, and relates to the technical field of mechanical vibration and noise control, a photonic crystal main body comprises an internal truss, an external hexagonal frame is arranged on the periphery of the internal truss, and the external hexagonal frame comprises a left side deformation beam, a right side deformation beam and a left side deformation beam; two first deformation beams are arranged on the right side of the left deformation beam, and transverse deformation beams are arranged on the right sides of the first deformation beams. The structure can effectively reduce the impact of vibration on key equipment and a basic structure in a complex vibration environment, the stability and safety of a system are greatly improved, and the structure is particularly suitable for the fields of manipulators, aerospace, automobile manufacturing, buildings, bridges and the like with extremely high vibration control requirements. Besides, the band gap range can be accurately regulated and controlled by adjusting the deformation of the photonic crystal, so that the photonic crystal is particularly suitable for being applied to a filter, unnecessary clutters can be filtered out, target waveforms can be reserved, and the practicability in vibration control and waveform processing is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical vibration and noise control, in particular to a phononic crystal with broadband elastic wave control and band gap active adjustment functions. Background Art

[0002] In recent years, phononic crystals have provided new ideas for the control of elastic waves such as vibration and noise due to their unique mechanical properties. Phononic crystals produce band gap characteristics through structural design, effectively suppressing vibration and noise in a specific frequency band, and have become a cutting-edge research in the field of vibration and noise reduction. This technology brings a new solution to the control of low-frequency vibration and broadband noise, showing great application potential. However, in traditional phononic crystal research, since its structure cannot be changed after production, it is difficult to meet the band gap and vibration and noise reduction requirements in different actual situations, thus limiting the application of phononic crystals. The method of using mechanical load to change the band gap of phononic crystals is simple and practical, and can be used as an effective way to explore phononic crystals with adjustable band gap characteristics.

[0003] The present invention aims to design a phononic crystal structure with broadband elastic wave control and active band gap adjustment functions. The structure consists of six periodically arranged regular hexagonal units, a truss structure is combined inside the unit, and the deformation beams are connected in a coaxial manner. The structure can deform under the action of external force and switch between different stable states, and can return to its original state after the external force is removed, showing adaptive deformation characteristics. The band gap width and position can be precisely adjusted by regulating the shape of the structure, thereby realizing multi-band vibration control and meeting the vibration suppression requirements in different frequency ranges.

[0004] Compared with traditional vibration and noise reduction materials, phononic crystals have the advantages of light weight, low internal friction, and good vibration and sound isolation properties, which enable vehicles and other means of transportation to achieve good smoothness and road and other environmental friendliness during operation. To this end, we propose a phononic crystal with broadband elastic wave control and active bandgap adjustment functions. Summary of the invention

[0005] The object of the present invention is to provide a phononic crystal with broadband elastic wave control and band gap active adjustment functions to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A phononic crystal with broadband elastic wave control and band gap active adjustment functions comprises a phononic crystal body, the phononic crystal body comprises an internal truss, an external hexagonal frame is arranged on the periphery of the internal truss, the external hexagonal frame comprises a left deformation beam, two groups of deformation beams 1 are arranged on the right side of the left deformation beam, a transverse deformation beam is arranged on the right side of the deformation beam 1, a deformation beam 2 is arranged on the right side of the transverse deformation beam, and a right deformation beam is commonly connected to the right side of the deformation beam 2, the internal truss comprises a central deformation beam, the central deformation beam is located in the middle of the inner cavity of the external hexagonal frame, springs are arranged at the top and bottom centers of the central deformation beam, the ends of the top and bottom springs away from the central deformation beam are connected to the inner wall of the transverse deformation beam, two groups of inner deformation beams are arranged on the left and right sides of the central deformation beam, and the ends of the inner deformation beams on the left and right sides away from the central deformation beam are respectively connected to the deformation beam 1 and the deformation beam 2.

[0008] Furthermore: the two groups of transverse deformation beams are arranged in parallel, and a protrusion matching the spring is arranged at the inner center of the transverse deformation beam.

[0009] Furthermore: the inner sides of the first deformable beam and the second deformable beam are both provided with mounting grooves matching the inner deformable beams.

[0010] Furthermore: bolts are provided at the connections between the left deformation beam, the deformation beam 1, the transverse deformation beam, the deformation beam 2, the right deformation beam, the inner deformation beam and the central deformation beam.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The phononic crystal has the functions of broadband elastic wave control and band gap active regulation. The phononic crystal is based on the Bragg scattering theory and produces a Bragg band gap, which can completely suppress elastic waves and form an absolute band gap, thereby realizing active control of broadband low-frequency vibration. Compared with traditional one-dimensional and two-dimensional vibration reduction and noise reduction materials, it has higher application value.

[0013] This phononic crystal achieves multi-band vibration control through an adjustable bandgap design, overcoming the limitation of the non-adjustable bandgap after traditional structure manufacturing. When the phononic crystal is subjected to external force, the angle θ varies from 110° to 160°, the lower boundary frequency of the first bandgap is regulated in the range of 386Hz to 439Hz, and the upper boundary frequency is regulated in the range of 935Hz to 1185Hz. As the angle θ increases, the width of the first bandgap gradually decreases and can be adjusted from 745Hz to 548Hz. The lower boundary frequency of the second bandgap is regulated in the range of 1794Hz to 1798Hz, and the upper boundary frequency is regulated in the range of 2223Hz to 3316Hz. As the angle θ increases, the width of the second bandgap gradually increases, and the bandgap width can be adjusted from 249Hz to 1518Hz, with a large regulation range. The change of the third bandgap is more significant, with the lower boundary frequency regulation range of 2237Hz to 4241Hz and the upper boundary frequency regulation range of 4097Hz to 4792Hz. It is worth noting that when the angle θ gradually increases to about 150°, the width of the third band gap is the smallest, only 75Hz; as the angle θ further increases, the width of the third band gap will gradually increase;

[0014] The phononic crystal can be prepared by 3D printing, and its versatility and quick installation are fully considered in the design. The overall structure is simple, the processing is convenient, and it is easy to install;

[0015] Compared with traditional phononic crystals, the present invention realizes multi-band vibration control through adjustable bandgap design, effectively overcoming the technical bottleneck of non-adjustable bandgap after manufacturing. The innovation of this phononic crystal lies in its unique adjustment mechanism, which can quickly restore the original state after structural deformation. At the same time, the parts are easy to install, flexible to adjust, high material utilization rate and low cost, and simple manufacturing process. In a complex vibration environment, this structure can effectively reduce the impact of vibration on key equipment and infrastructure, greatly improving the stability and safety of the system. This invention is particularly suitable for fields with extremely high requirements for vibration control, such as manipulators, aerospace, automobile manufacturing, and construction and bridges. In addition, adjusting the deformation of the phononic crystal can also accurately control the bandgap range, which makes it particularly suitable for filter applications, can filter out unnecessary clutter, retain the target waveform, and greatly improve the practicality in vibration control and waveform processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the phononic crystal of the present invention

[0017] Figure 2 Schematic diagram of the phononic crystal unit cell of the present invention

[0018] Figure 3 Schematic diagram of the internal truss of the phononic crystal unit cell of the present invention

[0019] Figure 4This is a schematic diagram of the band gap distribution of the phononic crystal proposed in the present invention at different angles.

[0020] In the figure: 1. Phononic crystal body; 2. Left deformation beam; 3. Deformation beam one; 4. Lateral deformation beam; 5. Deformation beam two; 6. Right deformation beam; 7. Inner deformation beam; 8. Spring; 9. Center deformation beam. DETAILED DESCRIPTION

[0021] 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.

[0022] Embodiment 1:

[0023] See also Figure 1-3The present invention provides a technical solution: a phononic crystal with broadband elastic wave control and band gap active adjustment function, comprising a phononic crystal body 1, the substrate of the phononic crystal body 1 can be prepared by additive manufacturing, injection molding, casting, sintering, wire cutting or mechanical processing, the entire phononic crystal body 1 is composed of a plurality of periodically arranged unit cells, and has excellent low-frequency broadband vibration reduction performance and band gap adjustment effect, the phononic crystal body 1 comprises an internal truss, the periphery of the internal truss is provided with an external hexagonal frame, the external hexagonal frame comprises a left deformation beam 2, two groups of deformation beams 1 3 are provided on the right side of the left deformation beam 2, a transverse deformation beam 4 is provided on the right side of the deformation beam 1 3, a deformation beam 2 5 is provided on the right side of the transverse deformation beam 4, a right deformation beam 6 is connected to the right side of the deformation beam 2 5, the left deformation beam 2, the deformation beam 1 3, the transverse deformation beam 4, the deformation beam 2 5, and the right deformation beam 6 are assembled into an external frame by bolts and nuts, wherein the deformation beam 1 3, the transverse deformation beam 4, the deformation beam 2 5, and the right deformation beam 6 are assembled into an external frame by bolts and nuts, wherein the deformation beam 1 3, the transverse deformation beam 4, the deformation beam 2 5, and the right deformation beam 6 are assembled into an external frame by bolts and nuts, The three types of beams, namely, deformable beam 4, deformable beam 2 and deformable beam 5, are installed symmetrically up and down. The internal truss includes a central deformable beam 9, which is located in the middle of the inner cavity of the external hexagonal frame. Springs 8 are arranged at the top and bottom centers of the central deformable beam 9. The springs 8 are prepared by cold forming or hot forming process. The ends of the top and bottom springs 8 away from the central deformable beam 9 are connected to the inner wall of the lateral deformable beam 4. The external hexagonal frame is connected to the internal truss through springs 8. The springs 8 have a small stiffness and their main function is to help the structure recover to its initial shape after the external force is removed. Two groups of inner deformable beams 7 are arranged on the left and right sides of the central deformable beam 9. The ends of the inner deformable beams 7 on the left and right sides away from the central deformable beam 9 are connected to deformable beam 1 3 and deformable beam 2 5 respectively. The four inner deformable beams 7 are combined in the middle of the deformable beam 1 3 and deformable beam 2 5 of the hexagonal external frame, and then the central deformable beam 9 is connected to the inner deformable beams 7. Finally, the hexagonal external frame is connected to the central deformable beam 9 through springs 8 to synthesize the overall phononic crystal unit cell. During subsequent adjustments or repairs, the beam structure can be quickly disassembled and assembled to achieve universal parts replacement. The deformation beam 1 3 and the deformation beam 2 5 of the hexagonal external frame are designed to rotate within an angle θ range of 110° to 160°. The lateral deformation beam 4 is connected to the central deformation beam 9 through a spring 8 with low stiffness. The main function of the spring 8 is to limit the position of the lateral deformation beam 4. When the left deformation beam 2 and the right deformation beam 6 are subjected to outward tension, the deformation beam 1 3, the deformation beam 2 5 and the four inner deformation beams 7 of the hexagonal external frame will rotate, causing the entire phononic crystal to expand in the horizontal direction and contract in the vertical direction. At the same time, the band gap of the structure will also change accordingly. When the outward tension disappears, the entire structure will restore the original shape of the phononic crystal under the action of the spring 8, thereby realizing active control of the band gap.

[0024] Preferably, the two groups of transverse deformation beams 4 are arranged in parallel, and a protrusion matching the spring 8 is arranged at the inner center of the transverse deformation beam 4, so that the stability after connection can be increased.

[0025] Preferably, the inner sides of the deformable beam 1 3 and the deformable beam 2 5 are both provided with mounting grooves matching the inner deformable beam 7 , and such a configuration can facilitate the installation of the inner deformable beam 7 .

[0026] Preferably, bolts are provided at the connections between the left deformation beam 2, deformation beam 1 3, lateral deformation beam 4, deformation beam 2 5, right deformation beam 6, inner deformation beam 7, and central deformation beam 9. Such an arrangement can rotate under the action of external force, thereby causing deformation of the overall structure of the phononic crystal, and can also facilitate disassembly and assembly.

[0027] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A phononic crystal with broadband elastic wave control and band gap active adjustment functions, comprising a phononic crystal body (1), characterized in that: The phononic crystal body (1) comprises an internal truss, an external hexagonal frame is arranged on the periphery of the internal truss, the external hexagonal frame comprises a left deformation beam (2), two groups of deformation beams (3) are arranged on the right side of the left deformation beam (2), a transverse deformation beam (4) is arranged on the right side of the deformation beams (3), a deformation beam (2) (5) is arranged on the right side of the transverse deformation beams (4), a right deformation beam (6) is arranged on the right side of the deformation beams (2), and the internal truss comprises a central deformation beam (9), the central deformation beam (9) is located in the middle of the inner cavity of the external hexagonal frame, springs (8) are arranged at the top and bottom centers of the central deformation beam (9), and the ends of the springs (8) at the top and bottom away from the central deformation beam (9) are connected to the inner wall of the transverse deformation beam (4), and two groups of inner deformation beams (7) are arranged on the left and right sides of the central deformation beam (9), and the ends of the inner deformation beams (7) at the left and right sides away from the central deformation beam (9) are respectively connected to the deformation beam 1 (3) and the deformation beam 2 (5).

2. The phononic crystal with broadband elastic wave control and band gap active adjustment function according to claim 1, characterized in that: The two groups of transverse deformation beams (4) are arranged in parallel, and a protrusion matching the spring (8) is arranged at the inner center of each transverse deformation beam (4).

3. The phononic crystal with broadband elastic wave control and band gap active adjustment function according to claim 1, characterized in that: The inner sides of the first deformable beam (3) and the second deformable beam (5) are both provided with mounting grooves matching the inner deformable beam (7).

4. The phononic crystal with broadband elastic wave control and band gap active adjustment function according to claim 1, characterized in that: Bolts are provided at the connections between the left deformation beam (2), the first deformation beam (3), the transverse deformation beam (4), the second deformation beam (5), the right deformation beam (6), the inner deformation beam (7) and the central deformation beam (9).

Images