Bandgap-adjustable metamaterial pipeline vibration absorber structure

Abstract

The present invention relates to the technical field of pipeline vibration control, disclosing a metamaterial pipeline vibration absorber structure with an adjustable bandgap. The structure comprises: a main oscillator module, mounted on the outer wall of a metamaterial pipeline substrate, which generates a local resonant bandgap based on the metamaterial's local resonance effect, suppressing the transmission of elastic waves within the pipeline and effectively controlling low-frequency vibrations; an additional oscillator module, adjustable and slidably arranged on the main oscillator module along the axial direction of the metamaterial pipeline substrate, to achieve adjustable and precise control of the metamaterial pipeline vibration suppression frequency band. The main oscillator module and the additional oscillator module work together to achieve low-frequency vibration suppression in the metamaterial pipeline. The resonant frequency of the additional oscillator is mechanically adjusted by sliding, dynamically expanding the bandgap range, resolving the contradiction between the fixed frequency band of traditional vibration absorbers and the complex and variable pipeline vibration.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline vibration control, and in particular to a metamaterial pipeline vibration absorber structure with adjustable band gap. Background Art

[0002] Pipelines are used to carry fluids, transferring energy, momentum, and mass. They are widely used in industries such as industry, shipbuilding, military, aerospace, marine, and nuclear industries. Equipment piping systems, characterized by numerous mechanical devices, complex excitation, and dense layout, are prone to complex and variable vibrations. The propagation of pipeline vibrations can induce strong vibrations and noise, seriously affecting the safety and concealment of equipment. It can also damage the piping system and its various precision instruments and equipment, cause structural fatigue and failure, shorten the life of the equipment, and affect its normal operation. In severe cases, it can cause pipeline ruptures, leading to piping system failure and catastrophic accidents. Therefore, the problem of controlling vibration in equipment piping is an urgent issue that needs to be addressed in the field of vibration reduction.

[0003] The primary source of pipeline vibration is the mechanical vibration generated by the pump during operation. Its vibration energy is primarily concentrated in low-frequency bands, such as the pump shaft frequency and blade frequency. Low-frequency line spectra below 200 Hz are particularly pronounced. Due to the varying pipeline structures and operating conditions of different equipment, pipeline vibration line spectra vary significantly. Traditional pipeline vibration reduction measures struggle to achieve uniform and effective vibration control for the complex vibrations of different pipelines. Complex pipeline vibration presents a severe challenge to existing vibration control technologies. There is an urgent need to develop novel vibration absorber structures that can effectively suppress pipeline vibrations in different pipeline structures and operating conditions, in order to effectively suppress the complex vibrations of equipment pipelines.

[0004] Currently, traditional pipeline vibration control methods primarily include mass-tuned damper technology, fluid vibration absorbers, damping vibration reduction structures, elastically supported vibration isolation structures, and flexible piping structures. These traditional methods can suppress high-frequency vibrations in pipelines, but they are unable to effectively suppress low-frequency vibrations and complex, variable vibration line spectra of the structure. Traditional vibration reduction technologies face significant technical bottlenecks: First, limited by the law of mass, they can only produce a single vibration reduction band, typically with a bandwidth of only tens of Hz. This narrow vibration control band prevents full coverage of broadband vibration suppression. Second, the pipeline vibration reduction structure is relatively fixed, resulting in a generally fixed vibration reduction frequency band. This structure cannot be adjusted to accommodate changes in the pipeline system's operating conditions or the pipeline's vibration line spectra, making it difficult to effectively suppress complex pipeline vibrations. Third, traditional metamaterial vibration absorbers typically require multiple units connected in parallel for multi-band vibration absorption, significantly increasing their size and making them difficult to deploy in space-constrained equipment piping systems. Summary of the Invention

[0005] The present invention provides a metamaterial pipeline vibration absorber structure with adjustable band gap to solve the technical problem that the existing traditional pipeline vibration control method cannot effectively suppress the low-frequency vibration and complex and variable vibration line spectrum of the structure.

[0006] The present invention provides a metamaterial pipeline vibration absorber structure with an adjustable band gap, comprising: a main oscillator module, which is used to be installed on the outer wall of a metamaterial pipeline substrate and generates a local resonance band gap based on the local resonance effect of the metamaterial, thereby suppressing the transmission of elastic waves in the pipeline and achieving effective control of low-frequency vibrations; an additional oscillator module, which is adjustably arranged on the main oscillator module along the axial sliding of the metamaterial pipeline substrate to achieve adjustable and precise control of the frequency band of the metamaterial pipeline vibration suppression; and the low-frequency vibration suppression of the metamaterial pipeline is achieved through the synergistic effect of the main oscillator module and the additional oscillator module.

[0007] Furthermore, the main oscillator module includes an elastic load-bearing ring and a mass ring. An elastic load-bearing ring is provided at each end of the mass ring. Both ends of the mass ring are fixed to the outer wall of the metamaterial pipe substrate through the elastic load-bearing ring; the inner wall surface of the mass ring is in contact with the outer wall surface of the elastic load-bearing ring, and the mass ring is fixedly connected to the elastic load-bearing ring.

[0008] Furthermore, the mass ring is composed of two half-ring units that are relatively buckled and connected.

[0009] Furthermore, the additional vibrator module is arranged on the mass ring via the sliding module; the sliding module includes a slide rail, a connecting clamp and a locking piece, the slide rail is arranged on the outer wall surface of the mass ring along the axial direction of the mass ring, and multiple slide rails are arranged at equal intervals along the circumference of the mass ring; the connecting clamp is arranged outside the mass ring along the circumferential ring of the mass ring and is fixedly connected to the additional vibrator module, and the connecting clamp and the additional vibrator module are jointly connected to the slide rail in a sliding manner, and the locking piece is arranged along the radial direction of the mass ring, and the connecting clamp and / or the additional vibrator module are locked on the mass ring by rotating the locking piece.

[0010] Furthermore, the two connecting clamps are respectively located at the two ends of the mass ring and are arranged opposite to each other. A synchronous driving mechanism is provided between the two connecting clamps, which drives the two connecting clamps to slide closer or farther relative to each other synchronously.

[0011] Furthermore, the synchronous drive mechanism includes a mounting boss, a gear and a rack; the mounting boss is arranged on the outer wall surface of the mass ring and is located at the center position between the two connecting retaining rings, the gear is rotatably arranged on the mounting boss, each connecting retaining ring is provided with an axially arranged rack and the rack is arranged toward the mounting boss, the racks of the two connecting retaining rings are relatively meshed and connected to the gears and the non-toothed edges of the racks are limited by the mounting boss; the gear is driven to rotate to drive the rack to move axially, thereby driving the two connecting retaining rings to slide closer or farther away synchronously.

[0012] Furthermore, the additional vibrator module includes a plurality of cantilever units, which are arranged on the connecting clamp along the axial direction of the connecting clamp and with the cantilevered end facing the side away from the mass ring. The plurality of cantilever units are arranged at equal intervals along the circumference of the connecting clamp.

[0013] Furthermore, the cantilever units on the two connecting clasps are arranged in a one-to-one correspondence; or the cantilever units on the two connecting clasps are arranged in a relatively staggered manner; or the number of cantilever units on the two connecting clasps is the same; or the number of cantilever units on the two connecting clasps is different.

[0014] Furthermore, the cantilever unit includes a cantilever beam and a tip mass block, the tip mass block is located on the cantilever end of the cantilever beam, and the connecting end of the cantilever beam is slidably connected to the slide rail and fixedly connected to the corresponding connecting clamp.

[0015] Furthermore, the cantilever beam and / or the tip mass block are made of metal material; and / or the mass ring is made of metal material, and the elastic load-bearing ring is made of viscoelastic material.

[0016] The present invention has the following beneficial effects:

[0017] 1. The main oscillator module generates a local resonance band gap based on the local resonance effect of metamaterials, which can effectively block the propagation of elastic waves in the pipeline at low frequencies, solving the problem of poor low-frequency vibration suppression effect of traditional vibration reduction technology.

[0018] 2. Through the precise design of the local resonance band gap, directional attenuation can be achieved for characteristic line spectra such as pump shaft frequency and blade frequency, significantly reducing the low-frequency vibration energy of the piping system.

[0019] 3. The design of the additional vibrator module that can slide and adjust along the axial direction of the pipeline allows the band gap range of the vibration absorber to be flexibly adjusted according to actual working conditions. By changing the position or number of the additional vibrator modules, different vibration line spectra can be adapted in real time, overcoming the defect that traditional fixed structures cannot adapt to changing vibration environments.

[0020] 4. The synergistic effect of the main oscillator module and the additional oscillator module can expand the band gap bandwidth and realize the simultaneous suppression of multi-band vibrations. Compared with traditional metamaterial vibration absorbers that require multiple units to be connected in parallel, the present invention can cover a wider frequency range through parameter adjustment of a single structure, solving the problem of contradiction between narrowband suppression and volume.

[0021] 5. The metamaterial pipeline vibration absorber structure with adjustable band gap of the present invention achieves the unification of efficient suppression of low-frequency vibration, adaptive matching of frequency bands and compact structure through the adjustable band gap design, solving the technical difficulties of complex vibration control in equipment piping systems. It is particularly suitable for application scenarios with strict requirements on concealment and reliability.

[0022] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 1 is a schematic structural diagram of a metamaterial circular tube vibration absorber with adjustable band gap according to a preferred embodiment of the present invention;

[0025] Figure 2 1 is a schematic cross-sectional structural diagram of a metamaterial circular tube vibration absorber with adjustable band gap according to a preferred embodiment of the present invention;

[0026] Figure 3 2. It is a structural diagram of a main oscillator module of a metamaterial pipeline vibration absorber according to a preferred embodiment of the present invention;

[0027] Figure 4 Schematic diagram of the cross-sectional structure of the main oscillator module of the metamaterial pipeline vibration absorber according to a preferred embodiment of the present invention;

[0028] Figure 5 2 is a schematic structural diagram of an additional vibrator module of a metamaterial pipeline vibration absorber according to a preferred embodiment of the present invention;

[0029] Figure 6 This is a schematic structural diagram of the assembly of a connecting ring, a gear, and a rack of a metamaterial pipeline vibration absorber according to a preferred embodiment of the present invention;

[0030] Figure 7 2 is a schematic structural diagram of periodically arranged pipelines of four metamaterial pipeline vibration absorbers according to a preferred embodiment of the present invention;

[0031] Figure 8 This is a diagram showing the energy band structure of a metamaterial pipeline vibration absorber according to a preferred embodiment of the present invention;

[0032] Figure 9 1. A comparison diagram of simulation results of vibration transmissibility-frequency curves of a pipeline installed with a metamaterial vibration absorber according to a preferred embodiment of the present invention and a control pipeline without a metamaterial vibration absorber installed;

[0033] Figure 10 Schematic diagram of the change in the extension length l of the cantilever beam in the metamaterial pipeline vibration absorber of the preferred embodiment of the present invention;

[0034] Figure 11 1. This is a graph showing the vibration transmissibility-frequency curve of a metamaterial pipeline vibration absorber installed under different cantilever beam extension lengths according to a preferred embodiment of the present invention;

[0035] Figure 12 1 is a schematic structural diagram of a metamaterial square pipe vibration absorber with adjustable band gap according to a preferred embodiment of the present invention;

[0036] Figure 13 2 is a schematic structural diagram of a main oscillator module of a metamaterial square pipe vibration absorber according to a preferred embodiment of the present invention;

[0037] Figure 14 Schematic diagram of periodically arranged pipelines of four metamaterial square pipeline vibration absorbers according to a preferred embodiment of the present invention;

[0038] Figure 15 3. A comparison diagram of simulation results of vibration transmissibility-frequency curves of a square pipe equipped with a metamaterial vibration absorber according to a preferred embodiment of the present invention and a control square pipe without a metamaterial vibration absorber;

[0039] Figure 16 1 is a schematic structural diagram of a guide mechanism according to a preferred embodiment of the present invention;

[0040] Figure 17 It is a structural schematic diagram of the synchronous driving mechanism and the guide mechanism of the preferred embodiment of the present invention.

[0041] Legend:

[0042] 100, metamaterial pipeline matrix; 200, elastic load-bearing ring; 300, mass ring; 400, slide rail; 500, connecting clamp; 600, locking piece; 700, mounting boss; 800, gear; 900, rack; 1000, cantilever beam; 1100, tip mass block; 1200, countersunk screw hole; 1300, guide rod; 1400, guide groove platform. DETAILED DESCRIPTION

[0043] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0044] like Figure 1 and Figure 2As shown, the bandgap-adjustable metamaterial pipeline vibration absorber structure of this embodiment includes: a main oscillator module, which is used to be installed on the outer wall of the metamaterial pipeline substrate 100, and generates a local resonance bandgap based on the local resonance effect of the metamaterial, thereby suppressing the transmission of elastic waves in the pipeline and achieving effective control of low-frequency vibration; an additional oscillator module, which is adjustably arranged on the main oscillator module along the axial sliding of the metamaterial pipeline substrate 100 to achieve adjustable and precise control of the metamaterial pipeline vibration suppression frequency band; low-frequency vibration suppression of the metamaterial pipeline is achieved through the synergistic effect of the main oscillator module and the additional oscillator module. The present invention features a metamaterial pipeline vibration absorber with adjustable bandgap. The main oscillator module generates a localized resonant bandgap based on the metamaterial's localized resonance effect, effectively blocking the propagation of elastic waves within the pipeline at low frequencies (particularly below 200 Hz). This addresses the poor low-frequency vibration suppression performance of conventional vibration reduction technologies. Through precise design of the localized resonant bandgap, targeted attenuation is achieved for characteristic line spectra such as the pump shaft frequency and blade frequency, significantly reducing the low-frequency vibration energy of the pipeline system. The design of the supplementary oscillator module, which slides and adjusts along the pipeline axis, allows the absorber's bandgap range to be flexibly adjusted based on actual operating conditions. By adjusting the position or number of supplementary oscillator modules, the absorber can adapt to different vibration line spectra in real time, overcoming the drawback of conventional fixed structures that are unable to adapt to changing vibration environments. The synergistic effect of the main and supplementary oscillator modules expands the bandgap bandwidth, enabling simultaneous suppression of vibrations in multiple frequency bands. Compared to conventional metamaterial vibration absorbers that require multiple units connected in parallel, the present invention can cover a wider frequency range through parameter adjustment of a single structure, resolving the trade-off between narrowband suppression and bulk. The modular design avoids the volume expansion problem caused by the traditional parallel connection of multiple units while ensuring the adjustability of the band gap. It is especially suitable for equipment piping systems with limited space. The main oscillator module is directly integrated into the outer wall of the pipeline, and the sliding adjustment of the additional oscillator module does not require a complex driving mechanism, which is convenient for actual installation and maintenance. By adjusting the position or combination of the additional oscillator modules, the target frequency band can be accurately matched, avoiding the "over-suppression" or "under-suppression" phenomenon caused by the fixed band gap in the traditional method. In addition, mechanical sliding adjustment is more adaptable to harsh working conditions such as high temperature and high pressure than electronic tuning, which improves the environmental robustness of the system. The metamaterial pipeline vibration absorber structure with adjustable band gap of the present invention achieves the unity of efficient suppression of low-frequency vibration, adaptive matching of frequency bands and compact structure through the adjustable band gap design, solves the technical problems of complex vibration control in equipment piping systems, and is especially suitable for application scenarios with strict requirements on concealment and reliability.

[0045] Metamaterial pipelines are specialized pipe structures designed based on metamaterials technology. Through artificially designed micro- or macroscopic structures, they achieve physical properties (such as acoustic, thermal, mechanical, or electromagnetic properties) unattainable with traditional materials. Metamaterial pipelines utilize artificially designed periodic structures to control elastic wave propagation, creating a band gap within a specific frequency range to block vibration transmission. Combined with the bandgap-adjustable metamaterial pipeline vibration absorber structure of the present invention, this achieves precise bandgap adjustment and low-frequency adaptability, thereby meeting the needs of equipment piping systems for broadband adjustable, compact, low-frequency vibration absorption.

[0046] like Figure 2 and Figure 4As shown, in this embodiment, the main oscillator module includes an elastic load ring 200 and a mass ring 300. An elastic load ring 200 is provided at each end of the mass ring 300, and both ends of the mass ring 300 are fixed to the outer wall of the metamaterial pipeline substrate 100 via the elastic load ring 200. The inner wall of the mass ring 300 is aligned with the outer wall of the elastic load ring 200, and the mass ring 300 is fixedly connected to the elastic load ring 200. The mass ring 300, through the elastic load rings 200 provided at both ends, forms a "mass-spring" resonance system, capable of generating significant localized resonance effects in the target low-frequency range (e.g., below 200 Hz). When coupled with the metamaterial pipeline substrate 100, this resonance system forms an elastic wave band gap within a specific frequency range, effectively blocking the propagation of low-frequency vibrations (e.g., pump shaft frequency and blade frequency) generated by equipment such as pumps along the pipeline. The close fit between the inner wall of the mass ring 300 and the outer wall of the elastic support ring 200 ensures an efficient transfer path for vibration energy from the metamaterial pipe base 100 to the elastic support ring 200 and then to the mass ring 300. The inertia of the mass ring 300 converts vibration kinetic energy into elastic potential energy, which is dissipated within the elastic support ring 200, thus avoiding the limitation of traditional damping materials that are only effective at high frequencies. The two elastic support rings 200 are symmetrically arranged at either end of the mass ring 300, forming a dual-support structure in the axial direction. This not only ensures the radial vibration freedom of the mass ring 300 (facilitating resonance tuning) but also suppresses unintended lateral vibration modes through symmetrical constraints, thereby improving the structural reliability of the vibration absorber under complex operating conditions. The elastic support ring 200 is directly fixed to the outer wall of the pipe, enabling modular installation without modifying the existing pipe structure. Conventional methods such as mechanical fastening or welding are used to secure the mass ring 300 to the elastic support ring 200, ensuring joint strength while accommodating installation requirements for pipes of varying diameters, significantly enhancing engineering applicability. The modular design provides a foundational platform for the subsequent integration of additional vibrator modules. The mass ring 300 serves as both the primary vibrator mass and its outer surface also serves as the mounting base for additional modules. By varying the density / volume of the mass ring 300 or the stiffness of the elastic support ring 200, the fundamental resonant frequency band can be pre-set, providing design freedom for precise bandgap adjustment. While ensuring low-frequency vibration absorption performance, this system also balances installation reliability, adaptability to operating conditions, and subsequent scalability, providing a fundamental solution for vibration control in equipment piping systems.

[0047] like Figure 1 、 Figure 2 、 Figure 3 and Figure 4As shown, in this embodiment, the mass ring 300 is composed of two semi-ring units that snap together relative to each other. The split semi-ring design allows for direct snap-fit ​​installation onto existing pipelines without disassembling the pipeline. This solves the installation challenge of traditional, integral mass rings, which must be installed from the end of the pipeline. This design is particularly suitable for retrofitting existing pipeline systems where space is limited or when installing them. The two semi-ring units utilize a symmetrical snap-fit ​​structure, generating uniform contact pressure along the circumference during tightening. This ensures that there is no localized stress concentration at the mating surface between the mass ring 300 and the elastic load-bearing ring 200, thus preventing the loss of vibration energy transfer efficiency due to poor contact. This symmetrical snap-fit ​​structure ensures strict axial symmetry in the mass distribution of the mass ring 300, eliminating the generation of additional eccentric centrifugal forces during vibration. This effectively prevents secondary vibrations caused by mass imbalance and ensures the stability of the vibration absorber. The split design allows for the individual removal and replacement of damaged semi-ring units without having to replace the entire mass ring 300, significantly reducing maintenance costs. When quality parameters need to be adjusted, fine-tuning can be achieved by replacing semi-ring units with different materials. The snap-fit ​​connection utilizes a concave-convex structure or reinforced connectors, ensuring the ease of separate installation while also ensuring the overall structural integrity of the mass ring 300 under high-frequency vibration conditions, thereby preventing vibration absorption performance degradation caused by loose connections. Optionally, the two half-ring units snap together and are connected using countersunk screw holes 1200 for bolts. Alternatively, the two half-ring units snap together and are flange-connected.

[0048] like Figure 1 、 Figure 2 、 Figure 3 and Figure 4As shown, in this embodiment, the additional vibrator module is arranged on the mass ring 300 via a sliding module; the sliding module includes a slide rail 400, a connecting clamp 500 and a locking member 600, the slide rail 400 is arranged on the outer wall surface of the mass ring 300 along the axial direction of the mass ring 300, and multiple slide rails 400 are arranged at equal intervals along the circumference of the mass ring 300; the connecting clamp 500 is arranged outside the mass ring 300 along the circumferential ring of the mass ring 300 and is fixedly connected to the additional vibrator module, and the connecting clamp 500 and the additional vibrator module are jointly connected to the slide rail 400 in a sliding manner, and the locking member 600 is arranged along the radial direction of the mass ring 300, and the connecting clamp 500 and / or the additional vibrator module are locked on the mass ring 300 by rotating the locking member 600. The multiple parallel circumferential rails 400, in conjunction with the connecting clamp 500, enable continuous axial adjustment of the additional vibrator module on the mass ring 300. By varying the position of the additional vibrator module, the resonant frequency of the overall system can be precisely controlled, achieving dynamic matching of the vibration absorption frequency band. The equally spaced circumferential arrangement of the rails 400 allows for selective placement of the additional vibrator modules. By configuring additional vibrator modules on different rails 400, specific vibration modes can be targeted and excited, achieving simultaneous absorption of multi-directional vibration energy. This addresses the difficulty of suppressing multi-dimensional vibrations with traditional single-point tuning. The radial locking mechanism of the locking element 600 ensures precise adjustment while allowing for rapid locking and unlocking. When the operating conditions of the piping system change (e.g., changes in fluid pressure causing a shift in the vibration spectrum), the additional vibrator module position can be adjusted instantly, forming the basis for a closed-loop "monitor-adjust-lock" control system, significantly improving adaptability under complex operating conditions. The integrated design of the connecting ring 500 and the additional vibrator module combines the sliding guide function with the mass block fixation function, eliminating the additional installation space required by traditional guide rail structures. Combined with the compact layout of the radial locking member 600, it achieves adjustable functionality while minimally increasing the overall structural thickness. The combined modular and integrated structural design meets the installation requirements of space-constrained scenarios. The locking member 600 utilizes a mechanical radial compression principle, converting the axial displacement generated by thread rotation into a radial locking force, creating a surface contact friction fixation between the connecting ring 500 and the slide rail 400. This provides greater resistance to loosening than traditional bolt-type lateral locking, maintaining the preset position unchanged under continuous vibration, and ensuring long-term reliability.

[0049] like Figure 3 and Figure 4As shown, in this embodiment, the two connecting rings 500 are located at the two ends of the mass ring 300 and are arranged relative to each other. A synchronous drive mechanism is provided between the two connecting rings 500, which drives the two connecting rings 500 to slide synchronously relative to each other or slide synchronously relative to each other. The synchronous drive mechanism forcibly controls the symmetrical movement of the two connecting rings 500, ensuring that the additional vibrator module always maintains a precise axially symmetrical position at both ends of the mass ring 300, eliminating the axial offset that may be caused by manual adjustment, and improving the adjustment accuracy of the vibration suppression frequency band. The synchronous reverse motion mechanism of the dual connecting rings 500 ensures that the mass distribution is always symmetrical about the midpoint of the mass ring 300, and no new mass eccentricity is introduced during the adjustment process. This effectively avoids the centrifugal force imbalance caused by traditional unilateral adjustment, allowing the system to maintain stable vibration absorption performance. By precisely controlling the relative distance between the two connecting rings 500, the high-order axial vibration modes of the mass ring 300 (such as the axial second-order vibration mode) can be specifically excited. When the spacing is a specific wavelength ratio, the vibrations of multiple characteristic frequencies can be simultaneously suppressed, achieving a multi-band control effect under single-degree-of-freedom adjustment. The synchronous drive mechanism enforces the motion consistency of the dual connecting rings 500 through mechanical linkage devices (such as gear racks and synchronous belts). Even if a single locking member 600 becomes slightly loose, the system can still maintain basic operating conditions through symmetric constraints, significantly improving fault tolerance in harsh environments such as battlefields. The kinematic coupling mechanism solves the problem of balancing precision and efficiency in adjustable vibration absorbers, ensuring that the equipment piping system can achieve rapid and precise adjustment of the vibration suppression frequency band under complex operating conditions.

[0050] like Figure 1 、 Figure 3 and Figure 6As shown, in this embodiment, the synchronous drive mechanism includes a mounting boss 700, a gear 800, and a rack 900. The mounting boss 700 is arranged on the outer wall surface of the mass ring 300 and is located in the center between the two connecting retaining rings 500. The gear 800 is rotatably arranged on the mounting boss 700. Each connecting retaining ring 500 is provided with an axially arranged rack 900, which is arranged toward the mounting boss 700. The racks 900 of the two connecting retaining rings 500 are relatively meshed and connected to the gears 800, and the non-toothed edges of the racks 900 are limited by the mounting boss 700. The gear 800 is driven to rotate to drive the rack 900 to move axially, thereby driving the two connecting retaining rings 500 to slide synchronously toward each other or away from each other. The meshing transmission between the gear 800 and the double rack 900 forms a strict kinematic coupling relationship, ensuring that the symmetrical movement error of the two connecting retaining rings 500 is small, thereby improving the adjustment accuracy. The beveled contact characteristics of the rack-and-pinion meshing pair create a self-locking effect, automatically resisting vibration-induced displacement when no driving force is applied. This maintains position without the need for additional braking devices, addressing the technical pain point of loosening in conventional sliding mechanisms. The symmetrically arranged dual racks 900 generate equal and opposite axial driving forces when the gear 800 rotates, ensuring that the two connecting rings 500 are always subjected to balanced interaction forces. This eliminates lateral bending moments caused by unilateral driving and reduces adjustment torque. The integrated design of the mounting boss 700 and the mass ring 300 highly integrates the gear 800 with the support structure. The position-limiting fit between the non-toothed edge of the rack 900 and the mounting boss 700 ensures linear motion without the need for traditional guide grooves. Mechanical interlocking achieves a balance between micron-level motion accuracy and kilonewton-level locking force, ensuring precise real-time frequency band control of the metamaterial vibration absorber in complex vibration environments. Optionally, multiple synchronous drive mechanisms are provided, spaced evenly around the circumference of the mass ring 300. Optionally, there are two sets of synchronous drive mechanisms, which are arranged opposite to each other. Figure 16 and Figure 17 As shown, a guide mechanism is provided on the other side of the mass ring 300 relative to the synchronous drive mechanism, i.e., on the opposite side of the synchronous drive mechanism. The guide mechanism includes a guide rod 1300 and a guide groove platform 1400. The guide groove platform 1400 is provided on the mass ring 300 and is arranged opposite the mounting boss 700. The connecting clamp 500 is provided with a guide rod 1300 arranged along the connecting clamp 500's axis. The guide rods 1300 of the two connecting clamps 500 are arranged in an offset manner and are slidably inserted into the guide grooves of the guide groove platform 1400. By coordinating multiple sets of synchronous drive mechanisms, or by coordinating the synchronous drive mechanisms with the guide mechanisms, mechanical balance is achieved, thereby enabling precise and stable adjustment of the additional vibrator module.

[0051] like Figure 1 、 Figure 2 and Figure 5 As shown, in this embodiment, the additional vibrator module includes a plurality of cantilever units. The cantilever units are arranged on the connecting clamp 500 along the axial direction of the connecting clamp 500, with the cantilever ends facing the side away from the mass ring 300. The plurality of cantilever units are arranged at equal intervals along the circumference of the connecting clamp 500. The cantilever structure of the cantilever unit forms a distributed mass-spring system in the axial and circumferential directions. When the connecting clamp 500 moves axially, the cantilever unit and the mass ring 300 produce multi-order coupled resonance, forming multiple suppression frequency bands. The cantilever units arranged at equal intervals in the circumferential direction form a periodic structure, and its vibration mode matches the circumferential wave number of the pipeline. The cantilever length of the cantilever unit and the moment of inertia of the section constitute an equivalent stiffness. When the effective length is changed by axial movement, the system simultaneously achieves a dual tuning effect of mass redistribution and stiffness reconstruction, so that a single adjustment action can simultaneously change multiple characteristic frequencies, thereby improving the adjustment efficiency.

[0052] like Figure 1 As shown, in this embodiment, the cantilever units on the two connecting clamps 500 are arranged in a one-to-one correspondence; or the cantilever units on the two connecting clamps 500 are arranged in a relatively staggered manner; or the number of cantilever units on the two connecting clamps 500 is the same; or the number of cantilever units on the two connecting clamps 500 is different. The one-to-one correspondence of the cantilever units is used to precisely match the vibration modes. The cantilever units on the two connecting clamps 500 are axially aligned to form a symmetrical periodic mass distribution, which can accurately excite axially symmetric vibration modes, especially for low-frequency vibrations caused by fluid pressure pulsation in the pipeline, to achieve insertion loss, and to maintain phase consistency to avoid modal interference. The cantilever units are arranged in a staggered manner to achieve wide-band suppression. The cantilever units are relatively staggered, and the system simultaneously excites axial and circumferential coupled modes, forming multiple separate suppression bands, which can synchronously suppress complex vibrations such as pump blade frequency and pipeline bending mode. The mass ratio optimization design adopts the same number of cantilever units, maintains the same number of double-ring cantilever units, and strictly symmetrically distributes the total mass of the system, avoiding additional centrifugal forces caused by mass imbalance. The arrangement of different numbers of cantilever units is adopted to achieve asymmetric frequency band compensation. By configuring the number of cantilever units differently, an asymmetric vibration suppression curve is formed on both sides of the system's natural frequency, which can compensate for the unbalanced vibration energy distribution of specific equipment pipelines. By designing different layout patterns of cantilever units, a single vibration absorber structure can be adapted to pipeline systems with different vibration spectrum characteristics, achieving rapid reconstruction of vibration suppression strategies under harsh working conditions such as submarines and spacecraft, and improving applicability compared to traditional fixed designs.

[0053] like Figure 1 、 Figure 2 and Figure 5As shown, in this embodiment, the cantilever unit includes a cantilever beam 1000 and a tip mass 1100. The tip mass 1100 is located at the cantilever end of the cantilever beam 1000. The connecting end of the cantilever beam 1000 is slidably connected to the slide rail 400 and fixedly connected to the corresponding connecting clamp 500. The cantilever beam 1000 provides equivalent stiffness, and the tip mass 1100 provides concentrated mass, forming a tunable "spring-mass" system. By adjusting the effective length l of the cantilever beam 1000 through sliding adjustment, the system's natural frequency and modal vibration shape can be simultaneously changed, achieving dual-degree-of-freedom tuning under single-parameter adjustment, and expanding the low-frequency vibration suppression bandwidth below 200 Hz. The bending vibration of the cantilever beam 1000, coupled with the radial vibration of the mass ring 300, can excite the system's second-order vibration modes and above, forming an additional vibration suppression band, compensating for the insufficient suppression of mid- and high-frequency frequencies by traditional local resonance structures, thereby improving overall insertion loss. The centralized arrangement of the tip mass blocks 1100 creates a radial mass gradient distribution, whose moment of inertia effectively suppresses the circumferential torsional vibration of the pipeline. When the cantilever beam 1000 slides axially, the tip mass blocks 1100 at its ends generate a controllable spatial interference effect with adjacent cantilever units.

[0054] In this embodiment, the cantilever beam 1000 and / or the tip mass 1100 are made of metal; and / or the mass ring 300 is made of metal, while the elastic load-bearing ring 200 is made of viscoelastic material. The metal cantilever beam 1000, tip mass 1100, and mass ring 300 form a high-rigidity load-bearing frame, ensuring that the vibration absorber does not plastically deform or fracture under long-term vibration loads. The viscoelastic elastic load-bearing ring 200 absorbs impact energy through flexible deformation. Together, these two components address the fatigue cracking issues of traditional all-metal structures and the insufficient load-bearing capacity of all-polymer structures. The metal components create a low-frequency localized resonant band gap through the high-density mass and rigid beam structure. The viscoelastic material dissipates mid- and high-frequency vibration energy through molecular chain friction. This rigid-flexible coupling design overcomes the frequency band limitations of a single material and enables full-band vibration control. The metal components ensure dimensional stability under high and low temperature conditions, preventing thermal expansion or embrittlement failure of the polymer material. The viscoelastic elastic load-bearing ring 200, through its large deformation capability, compensates for differences in thermal expansion coefficients between different materials, maintaining stable overall performance. The vibration kinetic energy of the metal mass ring 300 and cantilever beam 1000 is converted into heat through the shear deformation of the viscoelastic layer, forming a multi-stage dissipation path of "kinetic energy-elastic potential energy-heat energy". This improves energy conversion efficiency compared to the single resonance energy dissipation of pure metal structures. The high reflectivity of metal components to structure-borne sound waves combined with the viscoelastic material's absorption of airborne sound waves simultaneously suppresses vibration transmission and noise radiation, meeting the special requirements of concealment. Through the complementary optimization of physical properties, a synergistic improvement in vibration suppression performance, environmental adaptability, and engineering reliability is achieved without the need for complex active control.

[0055] During implementation, a metamaterial pipeline vibration absorber structure with adjustable bandgap is provided for suppressing low-frequency vibrations in pipelines. The structure comprises a main oscillator module and a frequency-adjustable additional oscillator module. The main structure comprises a metamaterial pipeline vibration absorber unit consisting of a metamaterial pipeline base 100, two elastic load-bearing rings 200, a mass ring 300, and eight sets of slidable "cantilever beam 1000-tip mass block 1100" oscillators. The metamaterial pipeline vibration absorber structure is mounted on the outer wall of the metamaterial pipeline base 100. The main oscillator module consists of a mass ring 300 and two elastic load-bearing rings 200. The inner walls of the mass rings 300 at both ends are fixedly connected to the outer walls of the elastic load-bearing rings 200. The inner walls of the two elastic load-bearing rings 200 are fixedly connected to the outer wall of the pipeline. Four slide rails 400 are evenly arranged along the circumference of the mass ring 300. The additional vibrator module consists of eight slidable cantilever beams 1000 and tip mass blocks 1100. One end of each cantilever beam 1000 is mounted on the slide rail 400 of the mass ring 300. Four cantilever beam 1000-tip mass block 1100 structures are mounted on each end of the mass ring 300. These four cantilever beams 1000 are connected in parallel via a connecting ring 500, enabling synchronized sliding within the slide rail 400. A rack 900 is mounted on the connecting ring 500. This meshes with a gear 800 mounted in the center of the mass ring 300, enabling synchronized adjustment of the position of the additional vibrator module. This sliding action allows for adjustable bandgap frequency in the metamaterial pipeline vibration absorber structure. The localized resonant bandgap of the metamaterial pipeline vibration absorber structure effectively suppresses low-frequency vibrations in the pipeline. Adjusting the extension of cantilever beam 1000 by rotating gear 800 adjusts the resonant frequency of the additional oscillator module, enabling dynamic tuning of the bandgap position and precise suppression of vibrations at different frequency bands in the pipeline. Mechanically adjusting the resonant frequency of the additional oscillator through sliding allows the bandgap range to be dynamically expanded, resolving the conflict between the fixed frequency band of traditional vibration absorbers and the complex and variable nature of pipeline vibrations.

[0056] A metamaterial pipeline vibration absorber structure with adjustable bandgap is used to control complex vibrations in pipelines. This metamaterial pipeline vibration absorber structure, arranged periodically or aperiodically along the pipeline, can suppress bending vibrations in multiple directions, including the internal and external surfaces of the pipeline. Dynamic adjustment of the vibration suppression frequency band can be achieved by adjusting the position of the additional oscillator. This allows for precise control based on the vibration characteristics of different pipelines or the same pipeline under different operating conditions. This allows for precise control of complex pipeline vibrations over a relatively wide frequency range, meeting the vibration suppression requirements under various operating conditions and addressing the difficulty of achieving precise vibration suppression for different pipelines under different operating conditions.

[0057] The bandgap-adjustable metamaterial pipeline vibration absorber structure includes a main vibrator module and an additional vibrator module. The main vibrator module is fixed to the outer wall of the metamaterial pipeline base 100 by bolts in countersunk screw holes. The additional vibrator module is fixed in the slide rails 400 around the main vibrator module. The additional vibrator module is fixed in parallel by connecting clamps 500. The synchronous movement of the additional vibrator module in the slide rails 400 is achieved by the meshing rotation of the gear 800 and the rack 900, and the position of the additional vibrator module is fixed by the fastening bolts (locking members 600) around the main vibrator module.

[0058] The main oscillator module consists of a mass ring 300 and two elastic load-bearing rings 200. The inner walls of the mass ring 300 are fixedly connected to the outer walls of the elastic load-bearing rings 200 at both ends, and the inner walls of the two elastic load-bearing rings 200 are fixedly connected to the outer wall of the metamaterial pipeline substrate 100. Four slide rails 400 are arranged at equal angles along the circumference of the mass ring 300 for the installation and sliding of the additional oscillator module. The middle portion of the outer wall of the mass ring 300 is provided with a mounting boss 700 for mounting a gear 800 and a rack 900. The main oscillator module functions by generating a local resonance band gap based on the local resonance effect of the metamaterial, effectively suppressing the transmission of elastic waves within the pipeline and achieving effective control of low-frequency vibrations.

[0059] like Figure 3 and Figure 4 As shown, the additional vibrator module is composed of eight slidable cantilever beams 1000 and eight pointed mass blocks 1100, which are fixedly connected to form a "spring-mass" vibrator. The additional vibrator module is connected to the mass ring 300 via a slide rail 400, and its frequency can be adjusted by sliding. The frequency of the additional vibrator module is changed by adjusting the position of the cantilever beams 1000. The additional vibrator modules at both ends of the mass ring 300 are symmetrical, ensuring balanced and equivalent multi-directional vibration suppression effects for both in-plane and out-of-plane bending of the pipeline. The additional vibrator module functions to generate an additional local resonant band gap, effectively widening the width of the metamaterial vibration absorber's vibration suppression band gap. At the same time, the adjustable structural design enables precise control of the band gap, thereby achieving precise vibration suppression for different pipelines or the same pipeline under different operating conditions. The local resonant band gap refers to a certain frequency range. Elastic waves within the band gap frequency range are suppressed and cannot propagate, while elastic waves outside the band gap frequency range can propagate normally without being affected. The bandgap frequency range of a metamaterial pipeline vibration absorber structure is related to the structure's natural frequency. When designing a metamaterial vibration absorber, the natural frequency can be tailored to the vibration transmission characteristics of different pipelines, effectively suppressing pipeline vibrations. In the frequency design of the main oscillator module, the mass ring can be modified through structural parameter design and material selection, while the elastic stiffness of the elastic support ring can be adjusted through structural and parameter design. By optimizing these two aspects, the frequency of the main oscillator module can be adjusted to generate a bandgap in the corresponding frequency range.

[0060] The mass ring 300 consists of two identical half-rings, fixedly connected to form a complete mass ring 300. This connection can be achieved through countersunk bolts, welding, or other methods. The mass ring 300 can be made of a high-density metal material (such as steel, copper, aluminum, or lead). Its inner wall is fixedly connected to the elastic load-bearing ring 200. The two can be secured using a high-strength adhesive or vulcanization. Four slidable rails 400 are evenly distributed along the circumference of the mass ring 300. Bolt bosses and fastening bolts are provided at each end of the rails 400. The cantilever beam 1000 in the additional vibrator module is mounted on the mass ring 300 via the rails 400 and secured with fastening bolts (locking members 600). A mounting boss 700 is located in the middle of the outer wall of the mass ring 300 for mounting the gear 800 and rack 900. The mass ring 300 can be made of metal or a high-density material, providing the mass portion of the "spring-mass" vibrator. Options include copper, steel, and lead. The mass ring 300 has an inner radius r3, an outer radius r4, and a length l1. Four slide rails are evenly spaced along the center of the mass ring's circumference. These rails have a height h1, a width b2, and a length l1. Fastening bolts are located on the outer ends of the rails to secure the cantilever beam. The elastic load ring is made of a high-damping material (damping ratio ζ ≥ 0.1), providing the spring portion and damping in the "spring-mass" oscillator. Options include silicone rubber, butyl rubber, and natural rubber. The elastic load ring has an inner radius r2 of 54 mm, an outer radius r3 of 76 mm, and a width b1 of 15 mm. Furthermore, the high damping effect of the elastic load ring material attenuates the vibration resonance peak of the pipeline, further enhancing the vibration reduction effect of the metamaterial absorber based on the bandgap vibration reduction mechanism.

[0061] like Figure 5As shown, the additional oscillator module of the bandgap-tunable metamaterial pipeline vibration absorber structure consists of a cantilever beam 1000 and a tip mass 1100. Both can be equivalent to a "spring-mass" oscillator. When suppressing pipeline elastic wave vibration, they can generate additional local resonant band gaps based on the original main oscillator band gap, thereby widening the band gap and effectively suppressing multi-band pipeline vibration. The cantilever beam 1000 is a slender square beam with a length of l2, a width of b2, and a height of h1. One end is provided with a slot for securing it to a connecting ring. It is made of metal, such as steel, copper, aluminum, or other alloy metals, and its primary function is to provide the spring portion of the "spring-mass" oscillator. The tip mass 1100 is a rectangular parallelepiped structure with a length of l3, a width of b2, and a height of h2. It is made of a high-density material, such as steel, copper, lead, an alloy metal, or other high-density materials, and its primary function is to provide the mass portion of the "spring-mass" oscillator. The two are fixedly connected as an additional vibrator module, attached to the slide rail 400 of the mass ring 300. Changing the position of the cantilever beam 1000 within the slide rail 400 changes the elastic stiffness of the cantilever beam 1000, thereby varying the natural frequency of the additional vibrator module. By varying the natural frequency of the "cantilever beam-tip mass" additional vibrator module, a new band gap position is added, enabling precise vibration suppression tailored to the pipeline's specific engineering application.

[0062] like Figure 6 As shown, the sliding adjustment module of the bandgap-adjustable metamaterial pipeline vibration absorber structure consists of a connecting ring 500, a rack 900, and a gear 800. The connecting ring 500 primarily connects the four cantilever beams 1000 at one end of the mass ring 300 in parallel, enabling the additional vibrator module to slide synchronously within the slide rail 400 of the mass ring 300. The rack 900 and gear 800 primarily adjust the position of the additional vibrator module and the extension length of the cantilever beams 1000 through meshing and rotation between the gear 800 and the rack 900, thereby achieving precise control of the additional vibrator module's frequency. The connecting ring 500, gear 800, and rack 900 are made of metal, such as steel, copper, aluminum, or other alloy metals. The connecting ring 500 has an inner radius of r4, an outer radius of r5, and a width of b3. A boss with a width of b4 is provided on the outside of the connecting ring for mounting and securing the rack. The rack has a length of l3.

[0063] The mass ring 300 of the metamaterial pipeline vibration absorber structure consists of two semicircular rings, connected by bolts through six countersunk screw holes 1200 on either side. The outer walls of the two elastic load rings 200 are fixedly connected to the inner walls of the mass ring 300. This can be secured with a high-strength adhesive (shear strength ≥ 15 MPa, tensile strength ≥ 20 MPa) or by vulcanization. The inner walls of the elastic load rings 200 are connected to the outer wall of the metamaterial pipeline base 100, secured to the base 100 by bolts in the countersunk screw holes, ensuring a stable structure. Eight additional vibrator modules consisting of cantilever beams 1000 and eight cutting-edge mass blocks 1100 are respectively installed in the slide rails 400 outside the mass ring 300, with four groups of additional vibrator modules installed at each end. The cantilever beams 1000 are inserted into the slide rails 400 and fixed in position by tightening bolts. The cantilever beams 1000 can slide in the slide rails 400 and thus change the stiffness of their equivalent springs, thereby realizing precise control of the band gap position of the metamaterial vibration absorber.

[0064] The additional vibrator modules are connected in parallel via two connecting rings 500 , each of which connects to four cantilever beams 1000 . A slot is provided at one end of each cantilever beam 1000 for securing the connecting rings 500 . A rack 900 is provided on one side of the connecting rings 500 . These racks 900 of the two connecting rings 500 simultaneously mesh with a gear 800 mounted in the middle of the outer wall of the mass ring 300 . The rotation of the gear 800 enables the additional vibrator modules to be moved within the slide rail 400 .

[0065] The elastic load ring 200 can be made of one or a combination of viscoelastic materials, such as butyl rubber, silicone rubber, and natural rubber. It effectively suppresses resonance peaks in the pipeline over a wide frequency range through a damping effect. The elastic load ring 200 is a circular ring structure mounted on the outer surface of the metamaterial pipeline substrate 100. The inner side of the elastic load ring 200 is connected to the outer surface of the metamaterial pipeline substrate 100, and the outer side is connected to the inner surface of the mass ring 300.

[0066] The cantilever beam 1000 can be made of metal materials such as steel and copper. The cantilever beam 1000 is a square beam structure and is installed in the slide rail 400 around the mass ring 300. By connecting the clamping ring 500 in parallel, multiple cantilever beams 1000 can slide synchronously and are fixed in position by tightening bolts (locking parts 600).

[0067] The tip mass block 1100 can be made of a high-density metal material (such as steel, copper, aluminum, lead). The tip mass block 1100 is a rectangular parallelepiped structure and is installed at one end of the cantilever beam 1000. The two can be fixed by welding or commonly used high-strength adhesives.

[0068] The number of metamaterial pipeline vibration absorber structures is multiple, such as Figure 7and Figure 14 As shown. Optionally, the metamaterial pipe vibration absorber structures are arranged on the metamaterial pipe substrate 100 at a certain interval of one period. By designing the interval of one period, the Bragg frequency of the pipe structure is close to the natural frequency of the metamaterial pipe vibration absorber. The Bragg band gap of the pipe substrate and the local resonance band gap of the metamaterial vibration absorber achieve coupling conditions, forming a wider coupling band gap, thereby effectively widening the vibration suppression band gap of the metamaterial pipe vibration absorber.

[0069] Based on the localized resonance mechanism of metamaterials and a design method for adjustable bandgap, this invention proposes a metamaterial pipeline vibration absorber structure with adjustable bandgap. The resonant frequencies of the metamaterial's main and auxiliary oscillator modules are specifically designed, effectively suppressing low-frequency vibrations in pipelines while maintaining a lightweight design. Furthermore, the adjustable position of the auxiliary oscillator module enables precise control of the frequency band for pipeline vibration suppression. This invention is applicable to vibration suppression in a variety of equipment pipeline systems, including those in transportation vehicles (ships, rail vehicles, aircraft, spacecraft, new energy vehicles, etc.), modern industrial engineering (transmission and substations, natural gas stations, tunnels, subway stations, etc.), and smart home systems (central air conditioners, refrigerators, washing machines, fresh air systems, etc.).

[0070] The present invention can generate two adjustable local resonance band gaps within a low-frequency range below 150 Hz, including a broadband band gap with a bandwidth exceeding 50 Hz. Furthermore, by adjusting the metamaterial pipeline vibration absorber structure, the band gap frequency band can be precisely controlled, achieving precise control of vibrations in different frequency bands and exhibiting excellent vibration control effects. The present invention designs a metamaterial pipeline vibration absorber structure based on the local resonance mechanism and the band gap adjustable design method. First, the main oscillator module and the additional oscillator module of the metamaterial pipeline vibration absorber structure are designed based on the local resonance mechanism. Both the main oscillator module and the additional oscillator module can generate local resonance band gaps, achieving the effect of "small size controlling large wavelength" based on the local resonance mechanism. Second, based on the design principle of adjustable band gap, a movable design of the additional oscillator is developed. By precisely adjusting the position of the additional oscillator, precise control of vibration under different working conditions of the pipeline is achieved. The present invention can overcome the shortcomings of the prior art, such as the inability to combine high reliability, low cost, and good vibration reduction performance in a low-frequency broadband range. At the same time, in order to address the problem that the vibration characteristics of different pipeline systems or the same pipeline system under different working conditions are complex and difficult to control, the present invention designs an additional vibrator module with adjustable position in the metamaterial pipeline vibration absorber. By adjusting the frequency of the additional vibrator, an adjustable design of the vibration suppression frequency band is achieved. A new adjustable band gap is introduced on the basis of the original band gap of the main vibrator module, thereby achieving effective control of complex vibrations of the pipeline under lightweight conditions.

[0071] The metamaterial pipeline vibration absorber structure exhibits excellent low-frequency vibration reduction properties. Based on the local resonance bandgap mechanism of metamaterials and the complex vibration characteristics of actual pipelines in engineering, this invention specifically designs the vibration suppression bandgap of the metamaterial pipeline vibration absorber structure. The proposed metamaterial pipeline vibration absorber structure effectively suppresses low-frequency vibrations in pipelines with a small size and minimal added mass. The efficiency of pipeline vibration suppression is further enhanced through the use of evenly spaced or unevenly spaced periodic arrangements.

[0072] The metamaterial pipeline vibration absorber structure features a dynamically adjustable bandgap frequency, enabling precise control of the bandgap frequency range. This invention utilizes a rack-and-pinion structure to synchronously adjust the position of the cantilever beam 1000 to alter the frequency of the additional oscillator, achieving an adjustable design for vibration suppression. This allows for the generation of multiple vibration suppression bandgaps across different frequency bands within the pipeline, enabling precise design for complex pipeline vibrations.

[0073] The metamaterial pipe vibration absorber structure exhibits significant broadband vibration suppression characteristics. By adjusting parameters such as the position of the cantilever beam 1000, the mass of the tip mass block 1100, and the material of the elastic support ring 200, the present invention gradually brings the band gap generated by the main oscillator module and the band gap generated by the additional oscillator closer together, generating band gap coupling, broadening the vibration reduction frequency band, and suppressing newly added resonance peaks.

[0074] The metamaterial pipeline vibration absorber structure has excellent damping and vibration reduction properties. The elastic load ring 200 proposed in this invention can be made of polymer damping material. By introducing polymer super-damping material into the metamaterial pipeline vibration absorber structure, it can effectively attenuate the various resonance peaks of the pipeline system, achieving better vibration suppression. It can also effectively widen the vibration band gap, enhancing the engineering application value of the structure.

[0075] Example 1:

[0076] In this embodiment, a simulation calculation is performed on the pipeline vibration transfer characteristics and energy band structure of a metamaterial pipeline vibration absorber structure with adjustable band gap. The calculation results are shown in FIG. Figure 8 、 Figure 9 As shown in FIG. 1 , the outer radius r2 of the metamaterial pipe substrate 100 is 54 mm, the inner radius r1 is 50 mm, the length a is 1.8 m, and the material is steel (with a density of 7850 kg / m³ and a Young's modulus of 2×10 11 Pa, Poisson's ratio is 0.3); the inner radius r2 of the elastic load ring 200 is 54 mm, the outer radius r3 is 76 mm, the width b1 is 15 mm, and its material is rubber (its density is 1300 kg / m³, and its Young's modulus is 2×10 7Pa, Poisson's ratio is 0.492, and damping ratio is 0.15); the inner radius r3 of the mass ring is 76 mm, the outer radius r4 is 88 mm, and the length l1 is 250 mm. The material of the mass ring is steel. Four slide rails 400 are evenly arranged in the middle of the circumference of the mass ring 300. The height h1 of the slide rail 400 is 5 mm, the width b2 is 20 mm, and the length l1 is 250 mm. The height h1 of the cantilever beam slide rail is 5 mm, the width b2 is 20 mm, and the length l2 is 230 mm. The material of the cantilever beam slide rail is steel. The height h2 of the tip mass block is 43 mm, the width b2 is 20 mm, and the length l3 is 60 mm. The material of the tip mass block is steel. The inner radius r4 of the connecting snap ring is 88mm, the outer radius r5 is 90mm, the width b3 is 10mm, the width b4 of the boss set on the outside of the connecting snap ring is 38mm, and its material is steel. The number of teeth of the rack is 17, the tooth top height is 2mm, the tooth root height is 2.5mm, the tooth width is 5mm, the tooth thickness is 3.142mm, and the rack length l3 is 103.142mm. The number of teeth of the gear is 18, the pitch circle diameter is 36mm, the tooth top circle diameter is 40mm, the tooth root circle diameter is 31mm, the base circle diameter is 33.829mm, the tooth top height is 2mm, the tooth root height is 2.5mm, the tooth width is 5mm, and the tooth thickness is 3.142mm.

[0077] The main oscillator module is directly connected to the metamaterial pipe matrix 100, and two elastic bearing rings 200 are fixed on the outer wall of the metamaterial pipe matrix 100 (see Figure 2 ), the outer wall of the elastic load-bearing ring 200 is fixedly connected to the inner wall of the mass ring 300. Each mass ring 300 consists of two half rings. Each half ring has three countersunk screw holes 1200 (with a diameter of 4 mm) on the upper and lower sides. The two half rings are fixedly connected by bolts with six countersunk screw holes 1200.

[0078] The additional vibrator module is connected to the mass ring 300 via a slide rail 400. One end of the module's cantilever beam 1000 is inserted into the slide rail 400. The four cantilever beams 1000 at one end of the slide rail 400 are connected in parallel via a connecting ring 500, allowing them to slide synchronously along the slide rail 400. A rack 900 is positioned on one side of the connecting ring 500. A gear 800 is positioned in the middle of the outer wall of the mass ring 300. The connecting rings 500 on either side of the slide rail 400 mesh with the gears 800 through the racks 900. Rotating the gears 800 synchronizes the cantilever beams 1000 at either end of the slide rail 400. Finally, tightening bolts (locking members 600) secure the cantilever beams 1000. The other end of the cantilever beam 1000 is fixedly connected to the tip mass block 1100 via gluing. Four cantilever beams 1000 are installed on both sides of each mass ring 300. The extension length l of the cantilever beams 1000 in the metamaterial pipeline vibration absorber structure is adjusted according to the vibration transfer characteristics of the metamaterial pipeline substrate 100. In the first embodiment, the extension length l of the cantilever beams is 150 mm.

[0079] The present invention simulates the band structure and vibration transfer characteristics of Example 1. First, a finite element simulation is performed on the band structure of the metamaterial pipe vibration absorber structure. During the simulation, an adaptive meshing strategy is first adopted to refine the mesh in key areas. Then, Bloch-Floquet periodic boundary conditions are applied to the boundaries of both ends of the metamaterial pipe vibration absorber to simulate an infinite periodic structure. The dispersion curve of the periodic structure is obtained through traversal scanning. The expression of the Bloch-Floquet periodic boundary condition is:

[0080] ;

[0081] Where r is the position vector, a is the lattice constant, and k is the Bloch wave vector. This boundary condition simplifies the infinite periodic structure into an eigenvalue solution problem of the unit cell model. The characteristic frequency ωn(k) changes with the wave vector to form the band curve. The band structure of the metamaterial vibration absorber structure is shown in the figure below. Figure 8 The metamaterial pipe vibration absorber structure in Example 1 can generate two band gaps of 51Hz-108Hz and 125Hz-135Hz in the low frequency band below 200Hz, effectively broadening the vibration suppression bandwidth of the dynamic vibration absorber under the same mass conditions.

[0082] To further verify its vibration suppression performance, the present invention conducted a simulation test on the vibration transfer characteristics of the metamaterial pipeline vibration absorber structure. The test object is a pipeline composed of four periodic arrangements of metamaterial pipeline vibration absorber structures with adjustable band gaps ( Figure 7 shown), Figure 9 This is a comparison of the vibration transmissibility of a pipeline with a metamaterial pipeline vibration absorber structure and a pure pipeline without a vibration absorber installed. Figure 9 It can be seen that the metamaterial pipeline vibration absorber structure exhibits effective vibration attenuation within the frequency bands of 50Hz-108Hz and 121Hz-130Hz, achieving a maximum vibration attenuation of 20dB, effectively controlling the low-frequency vibration of the pipeline system. Furthermore, simulation results show that the vibration suppression frequency band of the pipeline installed with the metamaterial pipeline vibration absorber structure is essentially consistent with the bandgap frequency band indicated by the aforementioned band structure calculation, further verifying the accuracy of the aforementioned calculation. Finally, simulation results show that in addition to the effective suppression of vibration within the bandgap frequency band, the various resonance peaks of the pipeline vibration are effectively attenuated. This is due to the use of high-damping rubber material in the elastic load ring 200, which further enhances the vibration suppression characteristics of the metamaterial pipeline vibration absorber.

[0083] In short, the metamaterial pipeline vibration absorber structure can effectively suppress the low-frequency vibration of the pipeline and provide effective technical support for the precise control of complex vibrations of equipment pipelines.

[0084] Example 2:

[0085] This example provides the calculation results of the vibration transmissibility of the additional oscillator module of the metamaterial pipeline vibration absorber structure under different position conditions. In this case, the outer radius r2 of the metamaterial pipeline base 100 is 54 mm, the inner radius r1 is 50 mm, the length a is 1.8 m, and the material is steel (with a density of 7850 kg / m³ and a Young's modulus of 2×10 11 Pa, Poisson's ratio is 0.3); the inner radius r2 of the elastic load ring 200 is 54 mm, the outer radius r3 is 76 mm, the width b1 is 15 mm, and its material is rubber (its density is 1300 kg / m³, and its Young's modulus is 2×10 7 Pa, Poisson's ratio is 0.492, and damping ratio is 0.15); the inner radius r3 of the mass ring is 76 mm, the outer radius r4 is 84 mm, and the length l1 is 250 mm. The material of the mass ring is steel. Four slide rails 400 are evenly arranged along the middle of the circumference of the mass ring. The height h1 of the slide rail 400 is 5 mm, the width b2 is 20 mm, and the length l1 is 250 mm. The height h1 of the cantilever beam 1000 and the slide rail 400 is 5 mm, the width b2 is 20 mm, and the length l2 is 200 mm. The material of the cantilever beam 1000 and the slide rail 400 is 5 mm, the width b2 is 20 mm, and the length l2 is 200 mm. The material of the cantilever beam 1000 is 43 mm, the width b2 is 20 mm, and the length l3 is 60 mm. The material of the tip mass block 1100 is steel. The inner radius r4 of the connecting snap ring is 88mm, the outer radius r5 is 90mm, the width b3 is 10mm, the width b4 of the boss set on the outside of the connecting snap ring is 38mm, and its material is steel. The number of teeth of the rack is 17, the tooth top height is 2mm, the tooth root height is 2.5mm, the tooth width is 5mm, the tooth thickness is 3.142mm, and the rack length l3 is 103.142mm. The number of teeth of the gear is 18, the pitch circle diameter is 36mm, the tooth top circle diameter is 40mm, the tooth root circle diameter is 31mm, the base circle diameter is 33.829mm, the tooth top height is 2mm, the tooth root height is 2.5mm, the tooth width is 5mm, and the tooth thickness is 3.142mm.

[0086] In this embodiment, the bandgap control characteristics of the metamaterial pipe vibration absorber were tested. During the simulation, four metamaterial pipe vibration absorbers were periodically arranged, while other material and structural parameters remained unchanged. The gears were rotated to cause the additional vibrator module to slide, and only the extension length l of the cantilever beam 1000 in the metamaterial pipe vibration absorber was changed. The schematic diagram of the structural change is shown in FIG. Figure 10 This embodiment calculates the vibration transmissibility curves of pipelines under different conditions such as the cantilever beam 1000 with an extension length of l=140㎜, l=150㎜, l=160㎜ and l=170㎜. The calculation results are shown in the figure. Figure 11 shown.

[0087] like Figure 11As shown, within the frequency range below 200 Hz, the bandgap frequency band of the metamaterial pipe vibration absorber structure changes significantly with changes in the length l of the cantilever beam 1000. Simultaneously, the metamaterial pipe vibration absorber structure effectively suppresses vibrations within each bandgap frequency band, with a maximum vibration attenuation of 26 dB. Calculation results show that the position of the localized resonant bandgap frequency band generated by the additional oscillator module shifts with changes in the extended length l of the cantilever beam 1000. As the extended length l of the cantilever beam 1000 increases, the additional bandgap (second bandgap) frequency band of the metamaterial pipe vibration absorber structure gradually shifts toward lower frequencies. This is because a larger extended length l of the cantilever beam 1000 in the additional oscillator module reduces the elastic stiffness provided, gradually reducing the resonant frequency of the additional oscillator module and shifting the bandgap frequency band toward lower frequencies. By adjusting the position of the cantilever beam 1000, the metamaterial pipe vibration absorber structure can effectively control vibrations within the 46 Hz to 145 Hz frequency band, broadening the vibration suppression bandwidth of the metamaterial pipe vibration absorber structure. In addition, by adjusting the extension length of the cantilever beam 1000 of the metamaterial pipeline vibration absorber structure, the vibration suppression band gap frequency band can be precisely controlled to achieve effective control of complex vibrations in the pipeline.

[0088] Example 3

[0089] In this example, the vibration transfer characteristic calculation results of a specific square metamaterial pipe vibration absorber are given. In order to further verify the vibration suppression characteristics of the metamaterial pipe vibration absorber on various different configurations of pipes in actual engineering, such as Figure 12 and Figure 13 As shown in the figure, this embodiment uses a square pipe commonly used in engineering practice as the vibration control object for simulation testing. The sliding adjustment module is omitted in the simulation calculation. The metamaterial pipe matrix 100 uses a square pipe structure. The outer side length c1 of the square pipe cross section is 88 mm, the wall thickness t1 is 4 mm, the length l is mm, and the material is steel (its density is 7850 kg / m³ and its Young's modulus is 2×10 11 Pa, Poisson's ratio is 0.3); the elastic load ring 200 is a square hollow ring structure, the outer side length c2 of the square hollow section is 108 mm, the wall thickness t2 is 10 mm, the length b1 is 15 mm, and the material is rubber (its density is 1300 kg / m³, and the Young's modulus is 2×10 7Pa, Poisson's ratio is 0.492, and damping ratio is 0.15); the mass ring 300 is a square hollow ring structure, the outer contour length c3 of its square hollow section is 132 mm, the wall thickness t3 is 12 mm, the length l1 is 250 mm, and its material is steel; four slide rails 400 are evenly arranged along the circumference of the mass ring 300, and the slide rail 400 has a height h1 of 5 mm, a width b2 of 20 mm, and a length l1 of 250 mm (the same as in Example 1); the cantilever beam 1000 and the slide rail 400 have a height h1 of 5 mm, a width b2 of 20 mm, and a length l2 of 200 mm, and their material is steel (the same as in Example 1); the height h2 of the tip mass block 1100 is 43 mm, the width b2 is 20 mm, and the length l3 is 60 mm, and its material is steel (the same as in Example 1).

[0090] Four metamaterial pipe vibration absorber structures are periodically arranged in a square pipe with an interval a of 1.8m and a total pipe length of 7.2m. Figure 12 and Figure 13 The square pipe structure with the metamaterial pipe vibration absorber structure is shown. According to the vibration transmission characteristics of the pipe base, the cantilever beam extension length l in the metamaterial pipe vibration absorber is adjusted. In the third embodiment, the cantilever beam extension length l is 160 mm.

[0091] The present invention simulates the pipeline vibration transfer characteristics of the third embodiment. The simulation calculation method is the same as that of the first embodiment. The calculation results are as follows: Figure 14 As shown, Figure 14 This is a comparison of the vibration transmissibility of a square pipe with a metamaterial pipe vibration absorber installed and a square pipe without a vibration absorber installed. Figure 14 It can be seen that the metamaterial pipe vibration absorber exhibits effective vibration attenuation in the 43Hz-55Hz and 73Hz-156Hz frequency bands, achieving up to 60dB of vibration attenuation. Calculations show that the metamaterial pipe vibration absorber can effectively control vibrations in square pipe structures at low frequencies below 200Hz. Furthermore, in addition to effectively suppressing vibrations within the bandgap frequency band, all resonant peaks of the pipe vibration are effectively attenuated.

[0092] Calculation results from Example 3 demonstrate that the proposed metamaterial pipe vibration absorber effectively suppresses vibrations across a wide range of pipeline configurations used in engineering applications. Compared to the circular pipes used in Example 1, the metamaterial pipe vibration absorber also achieves superior vibration reduction for square pipes. This demonstrates the versatility of the metamaterial pipe vibration absorber for pipelines in engineering applications and its high engineering application value.

[0093] Matters not covered by the present invention are known technologies.

[0094] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The above-described embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that a person skilled in the art would be able to make numerous modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0096] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A metamaterial pipeline vibration absorber structure with adjustable band gap, characterized in that: include: A main oscillator module is used for being installed on the outer wall of the metamaterial pipeline substrate (100), generating a local resonance band gap based on the local resonance effect of the metamaterial, suppressing the transmission of elastic waves in the pipeline, and achieving effective control of low-frequency vibration; The additional vibrator module is adjustably arranged on the main vibrator module by sliding along the axial direction of the metamaterial pipeline substrate (100), so as to achieve adjustable and precise control of the vibration suppression frequency band of the metamaterial pipeline; The low-frequency vibration suppression of the metamaterial pipeline is achieved through the synergistic effect of the main oscillator module and the additional oscillator module; The main oscillator module comprises an elastic bearing ring (200) and a mass ring (300); an elastic bearing ring (200) is respectively provided at both ends of the mass ring (300); both ends of the mass ring (300) are fixed to the outer wall of the metamaterial pipeline matrix (100) through the elastic bearing ring (200); the inner wall surface of the mass ring (300) is fitted with the outer wall surface of the elastic bearing ring (200), and the mass ring (300) is fixedly connected to the elastic bearing ring (200); The additional vibrator module is arranged on the mass ring (300) via the sliding module; the sliding module comprises a slide rail (400), a connecting clamp (500) and a locking member (600); the slide rail (400) is arranged on the outer wall surface of the mass ring (300) along the axial direction of the mass ring (300); a plurality of slide rails (400) are arranged at equal intervals along the circumference of the mass ring (300); the connecting clamp (500) is arranged outside the mass ring (300) along the circumference of the mass ring (300) and is fixedly connected to the additional vibrator module, and the connecting clamp (500) and the additional vibrator module are slidably connected to the slide rail (400); the locking member (600) is arranged along the radial direction of the mass ring (300); and the connecting clamp (500) and / or the additional vibrator module are locked on the mass ring (300) by rotating the locking member (600); The additional vibrator module comprises a plurality of cantilever units, the cantilever units being arranged on the connecting clamp ring (500) along the axial direction of the connecting clamp ring (500) and with the cantilever ends facing a side away from the mass ring (300), and the plurality of cantilever units being arranged at equal intervals along the circumference of the connecting clamp ring (500); The cantilever unit comprises a cantilever beam (1000) and a tip mass block (1100), wherein the tip mass block (1100) is located on the cantilever end of the cantilever beam (1000), and the connecting end of the cantilever beam (1000) is slidably connected to the slide rail (400) and fixedly connected to the corresponding connecting clamp (500).

2. The bandgap adjustable metamaterial pipeline vibration absorber structure according to claim 1, characterized in that: The mass ring (300) is composed of two half-ring units that are relatively buckled and connected.

3. The bandgap adjustable metamaterial pipeline vibration absorber structure according to claim 1, characterized in that: The two connecting clasps (500) are respectively located at the two ends of the mass ring (300) and are arranged opposite to each other. A synchronous driving mechanism is provided between the two connecting clasps (500), and the synchronous driving mechanism is used to drive the two connecting clasps (500) to slide closer or farther relative to each other synchronously.

4. The bandgap adjustable metamaterial pipeline vibration absorber structure according to claim 3, characterized in that: The synchronous drive mechanism comprises a mounting boss (700), a gear (800) and a rack (900); The mounting boss (700) is arranged on the outer wall surface of the mass ring (300) and is located at the center between the two connecting snap rings (500). The gear (800) is rotatably arranged on the mounting boss (700). Each connecting snap ring (500) is provided with an axially arranged rack (900) and the rack (900) is arranged toward the mounting boss (700). The racks (900) of the two connecting snap rings (500) are relatively meshed and connected to the gear (800) and the non-toothed edge of the rack (900) is limited via the mounting boss (700). The gear (800) is driven to rotate to drive the rack (900) to move axially, thereby driving the two connecting rings (500) to slide closer or farther away synchronously.

5. The bandgap-adjustable metamaterial pipeline vibration absorber structure according to any one of claims 1 to 4, characterized in that: The cantilever units on the two connecting clasps (500) are arranged in a one-to-one correspondence; or The cantilever units on the two connecting clasps (500) are arranged in a relatively staggered manner; or The number of cantilever units on the two connecting clasps (500) is the same; or The two connecting clamps (500) have different numbers of cantilever units.

6. The bandgap-adjustable metamaterial pipeline vibration absorber structure according to any one of claims 1 to 4, characterized in that: The cantilever beam (1000) and / or the tip mass (1100) are made of metal material; and / or The mass ring (300) is a metal material piece, and the elastic bearing ring (200) is a viscoelastic material piece.

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