Compact ultra-structure for broadband vibration suppression of a pipe and a design method thereof

Abstract

The application belongs to the technical field of vibration reduction, and discloses a compact superstructure for broadband vibration reduction of a pipeline and a design method thereof. The compact superstructure is used for vibration reduction of a pipeline body and comprises a superstructure unit cell. The superstructure unit cell is installed on the outer wall of the pipeline body. The superstructure unit cell is composed of 12 mass units and 30 connecting rods. Each mass unit is connected with 5 connecting rods and forms a icosahedron structure. The mass unit comprises a mass ball and an outer wrapping layer wrapped on the outer wall of the mass ball. The application has the beneficial effect that multi-directional and multi-frequency local resonance is realized through the spatial spring design of the superstructure unit cell and the spatial array distribution of the oscillators, and then multiple vibration reduction bands can be generated in multiple directions of the pipeline, so that broadband vibration reduction design of the pipeline under the condition of limited space is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vibration reduction, in particular to a compact superstructure for pipeline broadband vibration suppression and a design method thereof. BACKGROUND

[0002] The submarine pipeline system, as the core infrastructure of deep-sea equipment, undertakes the transportation function of fluid media such as fuel oil, lubricating oil and cooling water. While realizing the efficient transmission of fluid media, the pipeline system inevitably bears the effects of multi-source excitations such as fluid pulsation and mechanical vibration, causing three-dimensional multi-directional vibration responses in a broadband of tens to hundreds of hertz. This vibration energy propagates in the form of elastic waves through the pipeline structure and is ultimately converted into underwater radiated noise, which becomes one of the main sound emission sources in the silent cruising state of the submarine, directly threatening its acoustic stealth performance. However, due to the space constraints on board, the pipeline needs to be highly integrated with electronic equipment, bulkhead structures and pressure hulls, etc., resulting in highly dense arrangement of transverse and longitudinal pipelines. This narrow installation environment makes it difficult to implement traditional full-circumferential three-dimensional vibration reduction devices, and there is an urgent need to develop compact design technology for multi-directional broadband vibration suppression of pipelines under space constraints.

[0003] Traditional pipeline multi-directional vibration reduction technology mainly relies on full-circumferential spring-mass systems to achieve single-bandgap through local resonance effect. This technology has two significant technical bottlenecks: first, it can only produce a single vibration reduction band, with a bandwidth of generally only tens of Hz, which cannot achieve full-coverage broadband vibration suppression; second, full-circumferential design requires complete installation space, which is fundamentally contradictory to the engineering practice of densely arranged pipelines on board. Multi-frequency local resonance superstructure is an effective technical means to achieve broadband vibration reduction under small amplitude conditions, but the traditional design method requires the configuration of multiple independent spring-mass systems, which not only occupies a large amount of installation space, but also makes it difficult to achieve coordinated suppression of multi-directional vibration. If multi-frequency oscillators and springs can be integrated in space, and multi-directional multi-frequency local resonance bandgaps are formed through optimized array distribution, it is expected to achieve multi-directional broadband vibration suppression of pipelines through single-directional superstructure design, thereby breaking through the space constraints, which has important engineering significance for vibration reduction and noise reduction of submarine pipeline systems and acoustic stealth protection.

[0004] Therefore, it is necessary to provide a compact superstructure for pipeline broadband vibration suppression and a design method thereof, which can be used for multi-directional broadband vibration reduction of complex pipeline systems in submarines, unmanned underwater vehicles and other deep-sea equipment. SUMMARY

[0005] The present application discloses a compact superstructure for pipeline broadband vibration suppression and a design method thereof, which can effectively solve the technical problems involved in the background art.

[0006] To achieve the above-mentioned purpose, the technical solution of the present application is as follows:

[0007] A compact superstructure for pipeline broadband vibration suppression is used for vibration reduction of a pipeline body, and the compact superstructure comprises superstructure unit cells, which are mounted on the outer wall of the pipeline body, and each superstructure unit cell is composed of 12 mass units and 30 connecting rods, each mass unit is connected with 5 connecting rods and forms an icosahedron structure, and the mass unit comprises a mass sphere and an external wrapping layer wrapped on the outer wall of the mass sphere.

[0008] The present application aims to provide a compact superstructure for pipeline multidirectional broadband vibration reduction. The superstructure supports one-way arrangement, arbitrary circumferential design, and can be flexibly installed in space. It can realize multidirectional vibration absorption of 360° full circumference and broadband (0-1000 Hz) vibration suppression, effectively improve the space utilization, and meet the installation requirements under various working conditions. At the same time, the present application also provides a corresponding design method to solve the problem that the traditional vibration absorption structure is difficult to realize pipeline multidirectional broadband vibration reduction under the condition of small space in engineering.

[0009] As a preferred improvement of the present application: the mass sphere is made of metal, the external wrapping layer is made of viscoelastic material, and the connecting rod is made of viscoelastic material.

[0010] As a preferred improvement of the present application: the number of superstructure unit cells is multiple.

[0011] As a preferred improvement of the present application: a plurality of superstructure unit cells are arranged at equal intervals along the length direction of the pipeline body, and a plurality of superstructure unit cells are located on the same straight line or uniformly or non-uniformly distributed along the circumferential direction of the pipeline body.

[0012] As a preferred improvement of the present application: the compact superstructure further comprises a mounting base and a base upper boss, the mounting base is fixed on the pipeline body through a clamp, the base upper boss is mounted on the mounting base, the base upper boss is provided with a rod-shaped clamping groove and a hemispherical clamping groove, and the superstructure unit cell is fixed in the rod-shaped clamping groove and the hemispherical clamping groove through an adhesive.

[0013] As a preferred improvement of the present application: the superstructure unit cell is a central symmetric structure, and the superstructure unit cell has two parallel pentagonal planes, and the two parallel pentagonal planes are at an angle of 36° with respect to each other in the parallel plane.

[0014] A design method of a compact superstructure for pipeline broadband vibration suppression, comprising the following steps:

[0015] S1, vibration test is performed on the pipeline body without any additional structure, and the inherent resonance frequency and amplitude X1 of the pipeline in multiple directions are obtained;

[0016] S2, according to the resonance frequency of the pipeline body, the geometric parameters of the superstructure unit cell are preliminarily set;

[0017] S3, a finite element model of the superstructure unit cell is established;

[0018] S4, modal analysis is applied, vibration modes under different installation angles are simulated, and resonance frequencies of the superstructure unit cell in each direction are obtained;

[0019] S5, whether the resonance frequency of the superstructure unit cell covers the resonance frequency of the pipeline body is judged, and the judgment standard is that the resonance frequency of the superstructure unit cell is compared with the resonance frequency of the pipeline body, if the resonance frequency of the superstructure unit cell completely covers the resonance frequency of the pipeline body to be suppressed, then the next step is entered; if not covered, return to step S2, adjust the parameters of the superstructure unit cell, repeat modeling and analysis until the covering requirement is met;

[0020] S6, the superstructure unit cell is arranged according to the actual installation space of the pipeline body;

[0021] S7, a finite element model of the superstructure pipeline is established;

[0022] S8, the insertion loss IL of the superstructure pipeline is calculated, Wherein X2 is the amplitude of the measuring point of the superstructure pipeline;

[0023] S9, whether the simulation results and experimental test are consistent is verified, the insertion loss results of the finite element simulation are compared with the experimental test results, if the error is within the allowable range, then the next step is entered; if the error is too large, return to step S7, modify the model parameters and recalculate and verify;

[0024] S10, whether the vibration reduction performance of the superstructure pipeline meets the requirements is analyzed, whether the vibration reduction performance of the superstructure pipeline meets the requirements is judged, if it meets the requirements, then the next step is performed; if it does not meet the requirements, return to step S2 or S7, repeat the subsequent process until the requirements are met;

[0025] S11, the superstructure design parameters and arrangement results are output.

[0026] As a preferred improvement of the application: in step S1, a wideband white noise excitation is applied to the pipeline body by using a vibration excitation device, and an acceleration sensor is used to collect pipeline vibration response data at the end of the pipeline body;

[0027] In step S2, the geometric parameters include but are not limited to the size of the superstructure unit cell, the length of the connecting rod, the material density of the mass sphere and the elastic modulus of the connecting rod;

[0028] In step S3, finite element analysis software is used to perform three-dimensional modeling of the superstructure unit cell, define material properties of each component, divide the grid, and set boundary conditions. The finite element analysis software includes but is not limited to ANSYS and COMSOL;

[0029] In step S6, the number of additional superstructure units is determined according to the additional quality restrictions of the project, and the installation position and arrangement of the superstructure units are determined in combination with the shape of the pipeline body and the installation environment;

[0030] In step S7, based on the arranged superstructure pipe, an overall finite element model including the pipe body and the superstructure unit cell is established, and the contact settings of the connection interface between the pipe body and the superstructure unit cell are refined. The contact settings include but are not limited to binding contact and friction coefficient.

[0031] As a preferred improvement of the present invention: in step S9, the error is no more than 10%.

[0032] As a preferred improvement of the present invention: in step S10, the compliance standard is based on the insertion loss of actual experimental test being no less than 10 dB.

[0033] The beneficial effects of the present invention are as follows:

[0034] Through the spatial spring design of the superstructure unit cell and the spatial array distribution of the oscillators, multi-directional and multi-frequency local resonance is achieved, which can generate multiple vibration reduction belts in multiple directions of the pipeline, realizing the broadband vibration reduction design of the pipeline under limited space conditions.

[0035] Multidirectional vibration reduction can be achieved through the unidirectional arrangement of superstructures, realizing a compact design for multidirectional, broadband vibration reduction of pipelines under limited space conditions. Superstructure cells can be arbitrarily arranged around the circumference of the pipeline based on the installation space under actual working conditions. This not only does not reduce the pipeline's vibration reduction performance, but also potentially generates circumferential bandgap coupling, further widening the vibration reduction band. The physical mechanism of circumferential bandgap coupling here refers to the fact that superstructure cells installed at different angles have a slight offset in the bandgap frequency band within the same plane. These offset bandgaps, through the interference and superposition effects of vibration waves, form a wider comprehensive vibration reduction frequency band, breaking through the bandwidth limitations of traditional unidirectional uniform arrays.

[0036] The superstructure unit cell is adjustable. By adjusting parameters such as the unit cell spacing, the thickness or length of the rod, the vibration reduction performance can be optimized, band gap coupling can be generated, the vibration reduction frequency band can be widened, and new resonance peaks can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 is a schematic diagram of a one-way arranged superstructure pipe structure in the present application;

[0039] Figure 2 is a structural design diagram of a superstructure unit cell in the present application;

[0040] Figure 3 is a schematic diagram of a mass unit in the present application;

[0041] Figure 4 is a mounting base of a superstructure unit cell on a pipe in the present application;

[0042] Figure 5 is a schematic diagram of a one-way arranged superstructure pipe with different mounting angles in the present application;

[0043] Figure 6 is a schematic diagram of a pipe with circumferentially equiangular spiral arranged superstructure unit cells in the present application;

[0044] Figure 7 is a flow chart of a design method of a superstructure pipe in the present application;

[0045] Figure 8 is a comparison diagram of simulation and experimental results of an insertion loss-excitation frequency curve of a pipe output point position of a superstructure pipe;

[0046] Figure 9 is an insertion loss-excitation frequency curve of a pipe output point position of a unit cell under different mounting angles;

[0047] Figure 10 is an insertion loss-excitation frequency curve of a pipe output point position of a one-way arranged and spiral arranged superstructure unit cell.

[0048] In the drawings: 10-pipe body, 210-upper boss of the base, 211-rod-shaped clamping groove, 212-hemispherical clamping groove, 22-mounting base, 30-superstructure unit cell, 31-connecting rod, 320-mass unit, 321-mass ball, 322-external wrapping layer, 40-clamp. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0050] It should be noted that all the direction indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the direction indications also change accordingly.

[0051] In addition, the descriptions such as "first", "second" and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0052] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For a person of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0053] In addition, the technical solutions of each embodiment of the present application can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection claimed by the present application.

[0054] Please refer to Figure 1 As shown in the drawings, the present application provides a compact superstructure for broadband vibration suppression of a pipeline, which comprises superstructure unit cells 30, a mounting base 22 and a base upper boss 210, and the superstructure unit cells 30 are arranged on the pipeline body 10 at equal intervals. As shown in the drawings, Figure 2The superstructure unit cell 30 is composed of 12 mass units 320 of equal volume and mass and 30 connecting rods 31 of equal length, creating a centrosymmetric structure that ensures balanced and equivalent multi-directional vibration suppression. The three connecting rods 31 are connected by the nodes of the mass units 320, forming an equilateral triangle. Each node of the mass unit 320 is connected to five adjacent mass units 320 by five connecting rods 31, and the five adjacent mass units 320 are arranged in a regular pentagon (an icosahedron structure). Compared to designs with four or fewer connecting rods, this five-rod design significantly increases the number of modes in the overall superstructure unit cell (verified by modal analysis). The modal frequency distribution range extends from tens to several thousand Hz, effectively covering multiple resonance peaks within the target frequency band of the pipeline and producing a wide-band vibration reduction effect. However, when using a structure with six or more connecting rods, while the number of modes increases, the unit cell volume increases significantly (based on finite element parametric modeling data), significantly increasing the system space requirement and conflicting with the requirements of a compact equipment layout. Therefore, the five-bar connection structure achieves the optimal balance between modal coverage and space occupancy, and the regular polyhedron can produce the closest possible vibration absorption effect in all directions.

[0055] The plane distances (h1 and h3) between each mass unit 320 and the nodes of the five adjacent mass units 320 can be uniquely determined by the length l of the connecting rod 31 and the distance r from the midpoint of the regular pentagon to the mass unit. The superstructure unit cell 30 has two parallel regular pentagonal planes, and the distance h2 between them can also be uniquely determined by the length l of the connecting rod 31 and the distance r from the midpoint of the regular pentagon to the mass unit 320. . The two parallel regular pentagonal planes form an angle of 36° with each other in the parallel planes. The single mass unit 320 is composed of a metal mass ball 321 and an outer wrapping layer 322, which provides a spatial spring and an oscillator to produce a multi-directional resonance effect. The metal mass ball 321 is made of a high-density material (density ≥ 5g / cm³), and the optional range is steel, lead, etc. The outer wrapping layer 322 uses a high-damping material (damping ratio ζ ≥ 0.1), provides a spatial spring and damping, and the optional range is: rubber, plastic, etc. The thickness of the outer wrapping layer 322 should be less than 1 / 10 of the metal mass ball 321. The connecting rod 31 is made of viscoelastic material, provides damping and serves as a spring element, forms a local resonance system with the oscillator, and is made of the same material as the outer wrapping layer 322. The length of the connecting rod 31 must exceed the outer wrapping layer 322 of the single mass unit 320, and the cross-section is circular, and the cross-sectional diameter cannot exceed that of the single mass unit 320. The mounting base 22 has an arc-shaped mating surface that matches the surface of the pipe body 10, arranged symmetrically from top to bottom. Both sides are fastened to the pipe by clamps 40. The superstructure unit cells 30 can rotate 0°-360° around the pipe circumference, allowing for installation at appropriate angles to accommodate the varying installation spaces available at different locations on the pipe. Where installation space permits, the superstructure unit cells can be arranged in a unidirectional array for multi-directional vibration reduction, or in a spiral arrangement along the axial direction to form a three-dimensional array, stimulating circumferential bandgap coupling (bandgap coupling is not necessarily required, depending on the actual installation space) and broadening the vibration reduction frequency band. Circumferential bandgap coupling refers to the fact that the bandgap frequencies of superstructure unit cells installed at different angles within the same plane deviate slightly, and the interaction between these bandgaps results in bandgap widening.

[0056] The superstructure unit cell 30 is embedded in the rod-shaped slot 211 and the hemispherical slot 212. After positioning, it is fixed with a high-strength adhesive (shear strength ≥ 15MPa, tensile strength ≥ 20MPa), and then installed on the upper boss 210 of the base on the mounting base 22. The rod-shaped slot 211 is consistent in size with the connecting rod 31. The hemispherical slot 212 is consistent in size with the outer wrapping layer 322. The mounting base 22 is semicircular in shape, which can fit the surface of the pipe and is installed symmetrically up and down and pre-fixed on the surface of the pipe. The base and the pipe are fastened together on both sides by means of clamps 40 to ensure a stable structure. The preload force F of the clamp material is in the range of 500-800N. The material of the mounting base 22 and the upper boss 210 of the base should be a lightweight and high-rigidity material, and the optional range is: nylon material, carbon fiber reinforced composite material, aluminum alloy, etc. The superstructure unit cell 30 can be installed unidirectionally at a certain angle α (0≤α≤360°) (such as Figure 5 ), or it can be installed at different angles according to the installation space under actual engineering conditions (such as Figure 6 ), unidirectional installation means that each superstructure unit cell 30 is in a vertical plane.

[0057] The design method of compact superstructure with multi-directional pipeline broadband vibration suppression function has the following basic steps:

[0058] Step 1: Perform vibration test on the pipeline body 10 (light pipe) without any additional structure, apply broadband white noise excitation (such as 0~1000Hz) to the pipeline by using excitation equipment, and collect pipeline multi-directional vibration response data by using acceleration sensor. Obtain the inherent resonance frequency of the pipeline at different circumferential positions, provide frequency matching target for subsequent superstructure unit cell design, and clearly define the vibration frequency range to be suppressed.

[0059] Step 2: According to the resonance frequency of the light pipe, preliminarily set the geometric parameters (including the overall size of the superstructure unit cell 30, the diameter of the mass unit 320, the length of the connecting rod 31, the cross-sectional diameter, etc.), material parameters (including the material density of the metal mass sphere 321, the elastic modulus of the elastic connecting rod 31 and the external wrapping layer 322, the damping ratio, etc.), and combine engineering experience to determine the initial structure form of the unit cell with central symmetric five-directional connecting rod layout, and ensure that the unit cell has multi-directional vibration absorption capability.

[0060] Step 3: Establish the finite element model of the superstructure unit cell. Use professional finite element analysis software (such as ANSYS, COMSOL) to perform three-dimensional modeling of the superstructure unit cell, define the material properties (density, elastic modulus, damping parameters) of each component, divide the grid (use adaptive grid refinement to improve accuracy), and set the boundary conditions (such as free vibration boundary).

[0061] Step 4: Resonance modal analysis of superstructure unit cell 30 under different installation angles. Simulate the vibration mode under different installation angles (from 0° to 360°), obtain the resonance frequency of the unit cell in each direction, and clearly define the multi-directional vibration characteristics of the unit cell to ensure that its resonance frequency covers the inherent resonance frequency of the pipeline.

[0062] Step 5: Determine whether the unit cell resonance frequency covers the pipeline resonance frequency. Judgment standard: compare the resonance frequency of the superstructure unit cell 30 with the resonance frequency of the light pipe. If the unit cell resonance frequency completely covers the resonance frequency range to be suppressed of the pipeline, proceed to the next step; if not, return to the "initial parameter design of superstructure unit cell 30" section, adjust the unit cell parameters (such as optimizing the mass of the mass sphere 321 and the thickness of the connecting rod 31), repeat the modeling and analysis until the coverage requirement is met.

[0063] Step 6: Arrange and install the superstructure unit cell 30 according to the actual installation space of the pipeline. Combine the shape of the pipeline body 10, the installation environment (such as pipeline direction, space size limitation), determine the installation position, quantity and arrangement mode (such as periodic one-way array arrangement, non-one-way arrangement) of the superstructure unit cell 30.

[0064] Step 7: Create a finite element model of the superstructure pipe. Based on the arranged superstructure pipe, create a complete finite element model consisting of the pipe body 10, superstructure unit cells 30, mounting base 22, and upper boss 210. Refine the contact settings (e.g., binding contact and friction coefficient) at the interface between the pipe body 10 and superstructure unit cells 30 to ensure that the model faithfully reflects the actual structural dynamics.

[0065] Step 8: Calculate the insertion loss of the superstructure duct , where X1 is the amplitude at the measured point on the light pipe, and X2 is the amplitude of the superstructure pipe. Using a finite element model to simulate the pipeline vibration transmission process, the insertion loss IL of the superstructure pipe within the target frequency range is calculated. This allows the vibration reduction effect of the superstructure pipe to be quantified and its ability to suppress pipeline vibration to be evaluated.

[0066] Step 9: Verify the consistency between the simulation results and the experimental test results. Compare the insertion loss results of the finite element simulation with the experimental test results. If the error is within the allowable range (e.g., ≤10%), proceed to the next step. If the error is too large, return to the "Establishing the Finite Element Model of the Superstructure Pipe" step, modify the model parameters (such as material properties and contact settings), and recalculate and verify.

[0067] Step 10: Analyze whether the superstructure piping's vibration reduction performance meets requirements. Based on engineering vibration reduction indicators (e.g., insertion loss IL ≥ 10dB in the target frequency band), determine whether the superstructure piping's vibration reduction performance meets the standards. If so, output the design results. If not, return to adjust the superstructure unit cell parameters or layout, and repeat the subsequent process until the requirements are met.

[0068] Step 11: Output superstructure design parameters and layout results. Organize and output the geometric parameters of the superstructure unit cell 30 (such as mass unit dimensions and connecting rod 31 dimensions), material parameters (materials of various components), and installation layout (unit cell location, quantity, and installation angle) to form a complete superstructure piping design file. Example 1

[0069] This example gives the calculation and experimental results of the vibration reduction performance of a specific superstructure pipeline, such as Figure 8The pipe body 10 is made of non-plasticized polyvinyl chloride material (density 1350 kg / m3, Young's modulus 4.8e9 Pa, Poisson's ratio 0.319), the length of the pipe body 10 is 1 meter, the inner radius is 50 mm, and the outer radius is 55 mm. The interval of adjacent superstructure unit cells 30 is 200 mm, 5 superstructure unit cells are installed, and the arrangement direction of the superstructure unit cells 30 is in the same plane as the vibration measurement point, that is, the arrangement angle is 0°. According to the above superstructure design method, the metal mass sphere 321 is made of stainless steel material (density 7850 kg / m3, Young's modulus 2.1e11 Pa, Poisson's ratio 0.3), the installation base 22 is made of photosensitive resin material (density 1160 kg / m3, Young's modulus 2.48e9 Pa, Poisson's ratio 0.41), and the connecting rod 31 and the outer wrapping layer 322 are made of thermoplastic polyurethane elastomer rubber material (density 1200 kg / m3, Young's modulus 8e9 Pa, Poisson's ratio 0.4). The mass sphere 321 is 9 mm in diameter, the cross-sectional diameter of the connecting rod 31 is 3.6 mm, and the rod length is 22 mm. Figure 8 The experimental and simulation results show that the superstructure pipe exhibits multi-bandgap characteristics in the frequency range of 21-38 Hz and 160-221 Hz, achieving a reduction of up to 18 dB. These results indicate that the superstructure pipe effectively suppresses the propagation of vibration energy in the low frequency range, verifying the actual effectiveness of its bandgap characteristics. Example Two

[0070] In this example, the vibration reduction performance calculation results of a specific superstructure unit cell 30 at different arrangement angles around the pipe body 10 are given, as shown in Figure 9As shown, the pipe body 10 is made of vinyl chloride (density 1350 kg / m³, Young's modulus 3e9 Pa, Poisson's ratio 0.319), is 1 meter long, has an inner radius of 50 mm, and an outer radius of 55 mm. Adjacent cells are spaced 200 mm apart, and five superstructure cells 30 are installed, arranged at 0°, 45°, and 90° angles. Based on the above superstructure design method, the metal mass ball 321 is made of stainless steel (density 7850 kg / m³, Young's modulus 2.1e11 Pa, Poisson's ratio 0.3), the mounting base 22 is made of photosensitive resin (density 1160 kg / m³, Young's modulus 2.48e9 Pa, Poisson's ratio 0.41), and the connecting rod 31 and outer covering layer 322 are made of thermoplastic polyurethane elastomer rubber (density 1200 kg / m³, Young's modulus 8e9 Pa, Poisson's ratio 0.4). The mass ball 321 has a diameter of 9 mm, and the connecting rod 31 has a cross-sectional diameter of 3.6 mm and a length of 22 mm.

[0071] like Figure 9 As shown in the figure, within the frequency range of 100-200Hz, the average insertion loss of the superstructure pipe structure arranged at different angles exceeds 20dB. Among them, the superstructure pipe arranged at 90° along the excitation direction achieves the lowest frequency range and the widest vibration suppression band, with the highest insertion loss reaching 50dB; the superstructure pipe vibration suppression band arranged at 45° has a maximum insertion loss of 40dB; the superstructure pipe arranged at 0° along the excitation direction has a maximum insertion loss of 23dB. In all three cases, two vibration reduction band gaps are generated in the 0-300Hz range, showing a broadband vibration reduction effect. Example 3

[0072] This example gives the calculation results of the pipeline vibration reduction performance under the conditions of a specific unidirectional superstructure and a spiral superstructure, such as Figure 10The pipe body is made of vinyl chloride material (density 1350 kg / m3, Young's modulus 3e9 Pa, Poisson's ratio 0.319), the length of the pipe body is 1 meter, the inner radius is 50 mm, and the outer radius is 55 mm. The interval of adjacent unit cells is 160 mm, 6 superstructure unit cells are installed, the one-way superstructure arrangement direction is 0°, and the spiral arrangement superstructure refers to the included angle of adjacent two superstructure unit cells 30 being arranged in turn by rotating clockwise or counterclockwise by 60°. According to the above superstructure design method, the metal mass sphere 321 is made of stainless steel material (density 7850 kg / m3, Young's modulus 2.1e11 Pa, Poisson's ratio 0.3), the base 22 is made of photosensitive resin material (density 1160 kg / m3, Young's modulus 2.48e9 Pa, Poisson's ratio 0.41), and the connecting rod 31 and the outer wrapping layer 322 are made of thermoplastic polyurethane elastomer rubber material (density 1200 kg / m3, Young's modulus 8e9 Pa, Poisson's ratio 0.4). The mass sphere 321 has a diameter of 9 mm, and the cross-sectional diameter of the connecting rod 31 is 3.6 mm, and the rod length is 22 mm.

[0073] As shown in FIG. 6, the superstructure unit cells 30 are arranged in a spiral manner to produce multiple vibration reduction bands in the low frequency band of 0-300 Hz, and the low frequency vibration of the pipeline can also be effectively controlled. Figure 10 Compared with the pipeline with one-way arranged superstructure, the spiral arranged pipeline produces circumferential band gap coupling, so that the vibration reduction band is further widened, the newly added overflow amplitude is reduced to a certain extent, the frequency vibration control can be realized in a wider range, and the vibration suppression effect is more significant.

[0074] Through the spatial spring design of the superstructure unit cell and the spatial array distribution of the oscillator, multi-directional and multi-frequency local resonance is realized, and multiple vibration reduction bands can be produced in multiple directions of the pipeline, realizing wide frequency vibration reduction design. The pipeline multi-directional vibration reduction can be realized by one-way arrangement of the superstructure, realizing the compact design of the pipeline multi-directional and wide frequency vibration reduction under the condition of limited space. The superstructure unit cell can be arranged in the circumferential direction of the pipeline according to the installation space of the pipeline under actual working conditions, which will not reduce the vibration reduction performance of the pipeline, and may also produce circumferential band gap coupling to further widen the vibration reduction band. The physical mechanism of the circumferential band gap coupling is that the band gaps of the superstructure unit cells with different installation angles have small offsets in the same plane. Through the interference and superposition effect of the vibration waves, the offset band gaps form a wider comprehensive vibration reduction frequency band, breaking through the bandwidth limitation of the traditional same direction uniform array. The superstructure unit cell is adjustable. By adjusting the cell spacing, rod thickness or length and other parameters, the vibration reduction performance can be optimized, the band gap coupling can be produced, the vibration reduction frequency band can be widened, and the newly added resonance peak can be suppressed.

[0075] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and the embodiments. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A compact superstructure device for suppressing broadband vibration of a pipeline, used for reducing vibration of a pipeline body (10), characterized by: The compact superstructure includes a superstructure unit cell (30), the superstructure unit cell (30) being mounted on the outer wall of the pipe body (10), the superstructure unit cell (30) being composed of 12 mass units (320) and 30 connecting rods (31), each of the mass units (320) being connected to five connecting rods (31) to form an icosahedral structure, and the mass unit (320) including a mass ball (321) and an outer wrapping layer (322) covering the outer wall of the mass ball (321); The mass ball (321) is made of metal, the outer wrapping layer (322) is made of viscoelastic material, and the connecting rod (31) is made of viscoelastic material; the number of the superstructure unit cells (30) is multiple, and the multiple superstructure unit cells (30) are arranged at equal intervals along the length direction of the pipe body (10), and the multiple superstructure unit cells (30) are located in the same straight line or are uniformly or non-uniformly distributed along the circumference of the pipe body (10); the compact superstructure further includes a mounting base (22) and a base upper boss (210), and the mounting base (22) is connected to the pipe body (10) by a clamp (4 0) is fixed on the pipe body (10), the upper boss (210) of the base is installed on the mounting base (22), the upper boss (210) of the base is provided with a rod-shaped slot (211) and a hemispherical slot (212), and the superstructure unit cell (30) is fixed to the rod-shaped slot (211) and the hemispherical slot (212) by an adhesive; the superstructure unit cell (30) is a centrally symmetrical structure, and the superstructure unit cell (30) has two parallel regular pentagonal planes, and the two parallel regular pentagonal planes form an angle of 36° with each other in the parallel planes.

2. The design method of a compact superstructure device for broadband vibration suppression of pipelines according to claim 1 is characterized in that: The following steps are involved: S1, performing a vibration test on the pipeline body (10) without any additional structure to obtain the multi-directional natural resonance frequency and amplitude X1 of the pipeline itself; S2. Preliminarily setting the geometric parameters of the superstructure unit cell (30) according to the resonance frequency of the pipeline body (10); S3. Establish a finite element model of the superstructure unit cell; S4, applying modal analysis to simulate vibration modes at different installation angles and obtaining the resonant frequencies of the superstructure unit cell (30) in various directions; S5. Determine whether the resonance frequency of the superstructure unit cell (30) covers the resonance frequency of the pipeline body (10). The judgment standard is: compare the resonance frequency of the superstructure unit cell (30) with the resonance frequency of the pipeline body (10). If the resonance frequency of the superstructure unit cell (30) completely covers the resonance frequency band of the pipeline body (10) that needs to be suppressed, proceed to the next step; if not, return to step S2, adjust the parameters of the superstructure unit cell (30), and repeat the modeling and analysis until the coverage requirement is met. S6. Install the superstructure unit cell (30) according to the actual installation space arrangement of the pipeline body (10); S7. Establish a finite element model of the superstructure pipeline; S8. Calculate the insertion loss IL of the superstructure duct. , where X2 is the amplitude of the measuring point of the superstructure pipe; S9. Verify whether the simulation results are consistent with the experimental test results. Compare the insertion loss results of the finite element simulation with the experimental test results. If the error is within the allowable range, proceed to the next step. If the error is too large, return to step S7, correct the model parameters, and recalculate and verify; S10, analyzing whether the vibration reduction performance of the superstructure pipeline meets the requirements, and determining whether the vibration reduction performance of the superstructure pipeline meets the standards. If so, proceed to the next step; if not, return to step S2 or S7, and repeat the subsequent process until the requirements are met; S11. Output superstructure design parameters and layout results.

3. The design method according to claim 2, characterized in that: In step S1, a wide-band white noise excitation is applied to the pipeline body (10) using an excitation device, a measuring point is selected at the end of the pipeline body (10), and pipeline vibration response data is collected using an acceleration sensor; In the step S2, the geometric parameters include but are not limited to the size of the superstructure unit cell (30), the length of the connecting rod (31), the material density of the mass ball (321) and the elastic modulus of the connecting rod (31); In step S3, a finite element analysis software is used to perform three-dimensional modeling on the superstructure unit cell (30), define the material properties of each component, divide the grid, and set boundary conditions. The finite element analysis software includes but is not limited to ANSYS and COMSOL; In step S6, the number of additional superstructure cells (30) is determined according to the additional quality restriction of the project, and the installation position and arrangement of the superstructure cells (30) are determined in combination with the shape of the pipeline body (10) and the installation environment; In step S7, based on the arranged superstructure pipe, an overall finite element model including the pipe body (10) and the superstructure unit cell (30) is established, and the contact settings of the connection interface between the pipe body (10) and the superstructure unit cell (30) are refined, and the contact settings include but are not limited to binding contact and friction coefficient.

4. The design method according to claim 2, wherein: In step S9, the error is no more than 10%.

5. The design method according to claim 2, wherein: In step S10, the compliance standard is based on the insertion loss of the actual experimental test being no less than 10 dB.

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