Vibration reduction buffer protection superstructure based on local resonance and compression-torsion coupling

Abstract

The invention relates to a vibration damping and buffering protection superstructure based on local resonance and compression-torsion coupling. The vibration damping and buffering protection superstructure comprises a middle circular ring and two compression-torsion pipes, wherein the two compression-torsion pipes are symmetrically arranged with the middle circular ring as the center in a chiral mode. Each pressure torsion pipe comprises an outer circular ring and a connecting rod; the outer circular ring and the middle circular ring are coaxially arranged; two ends of the connecting rod are respectively connected to the middle circular ring and the outer circular ring; the plurality of connecting rods are uniformly arranged along the middle circular ring; and a resonance ball is arranged on each connecting rod in a penetrating manner. When vibration or impact invasion occurs, the superstructure generates a local resonance effect and a compression-torsion coupling mechanism, and the wave energy dissipation efficiency is better and more stable. Through the chiral symmetric pressure torsion tube, coupling of longitudinal and torsional deformation modes is realized, and polarization of longitudinal waves and torsional waves is promoted. Therefore, the polarized band gap can be induced to block longitudinal waves. Meanwhile, the resonance balls on the connecting rods generate a remarkable local resonance effect, and wave energy is dissipated through local resonance. According to the invention, impact protection and vibration isolation performance can be synergistically improved.

Description

Technical Field

[0001] The invention relates to the technical field of vibration and impact protection, and in particular to a vibration reduction, buffering and protection superstructure based on local resonance and compression-torsion coupling. Background Art

[0002] With the continuous development of lightweight and high-end precision modern engineering equipment, the requirements for structures and materials in actual engineering applications are gradually showing a trend of multifunctionality.

[0003] Superstructures are a type of artificially constructed materials with functions or properties that do not exist in nature. By utilizing their special wave and mechanical properties, they can achieve efficient vibration isolation, energy absorption, and impact protection. The local resonant superstructure proposed by Liu Zhengyou et al. ([1] Z Liu, X Zhang, Y Mao, et al. Locally resonant sonic materials. Science, 2000, 289(5485): 1734-1736) has created a new paradigm in the field of vibration and noise research. This technology forms a "spring-oscillator" system by periodically embedding lead ball resonators in a silicone rubber matrix, which produces a local resonance effect. This technology has been proven to achieve elastic wave attenuation and controllable elastic wave manipulation in the subwavelength range, and has great potential for realizing vibration reduction and buffering functions. The local resonance effect utilizes the mismatch of wave impedance between the resonant unit and the matrix, causing strong energy localization during elastic wave propagation, inducing controllable elastic wave dispersion and band gap that are independent of the structure size, thereby achieving efficient elastic wave attenuation and impact relief. On the other hand, the compression-torsion structure has a special deformation mode of axial compression coupled with circumferential torsion, which produces many practical mechanical phenomena. Miyazawa et al. found that the metamaterial based on Kresling origami has a polarization effect of mutual conversion between torsional waves and longitudinal waves. The compression-torsion coupling phenomenon causes the longitudinal wave input at the excitation end to decouple during propagation and transform into elastic waves of multiple modes, thereby achieving the isolation of the longitudinal wave. ([2] Miyazawa Y, Chen CW, Chaunsali R, et al. Topological state transfer in Kresling origami. Communications Materials, 2022, 3(1):62).

[0004] Current technological developments have shown that local resonance and compression-torsion coupling are highly complementary: the former has excellent wave attenuation capabilities but limited wave polarization and modulation capabilities, while the latter can decouple the conversion of wave modes but lacks a way to dissipate wave energy. Therefore, by synergizing these two phenomena to achieve complementary advantages, it is expected that efficient wave attenuation can be achieved while polarizing elastic waves, thereby achieving significant vibration isolation and shock relief effects.

[0005] Research shows that although the local resonance effect can form a low-frequency, wide-band gap by constructing a "spring-oscillator" system, the introduction of an additional resonator brings difficulties to the manufacture and application of the superstructure, resulting in difficulties in structural assembly in practical applications and insufficient durability in long-term applications. On the other hand, although the compression-torsion coupling mechanism can achieve stable elastic wave polarization by changing the deformation mode of the structure, the regulation of the band gap and the attenuation of the wave based on this mechanism are limited. If the band gap range is to be expanded, damping often needs to be increased, but this will cause a decrease in structural strength. Summary of the invention

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to provide a vibration-damping and buffering protective superstructure based on local resonance and compression-torsion coupling, which can synergistically improve impact protection and vibration isolation performance.

[0007] In order to achieve the above object, the present invention adopts the following technical solution: A vibration-damping, buffering and protective superstructure based on local resonance and compression-torsion coupling, comprising a central ring and two compression-torsion tubes arranged chirally symmetrically with the central ring as the center; Each compression and twisting tube comprises an outer ring and a connecting rod; The outer ring and the middle ring are coaxially arranged; The connecting rod is tilted, and its two ends are respectively connected to the middle ring and the outer ring; There are multiple connecting rods, and the multiple connecting rods are evenly arranged along the middle ring; A resonant ball is passed through each connecting rod.

[0008] Furthermore, the resonant ball is embedded in the center of the connecting rod.

[0009] Furthermore, in each compression-twist tube, the number of connecting rods is six.

[0010] Furthermore, the vibration-damping, buffering and protective superstructure is prepared by integrated 3D printing.

[0011] Furthermore, the vibration-damping, buffering and protective superstructure is processed using an aluminum alloy substrate.

[0012] In general, the present invention has the following advantages: When the superstructure of the present invention is invaded by vibration or impact, the superstructure will generate a local resonance effect and a compression-torsion coupling mechanism, with better and more stable wave energy dissipation efficiency. Through the chiral symmetric compression-torsion tube, the coupling of longitudinal and torsional deformation modes is realized, promoting the polarization of longitudinal waves and torsional waves. Therefore, a polarization band gap can be induced to block longitudinal waves. At the same time, the resonant balls on the connecting rods produce a significant local resonance effect, and the two can be idealized as a "spring-oscillator" system to dissipate wave energy using local resonance. The damping and buffering protection superstructure proposed by the present invention is mainly for the application of comprehensive protection against vibration and impact, that is, for continuous vibration isolation and instantaneous impact mitigation, and can synergistically improve impact protection and vibration isolation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 FIG. is a schematic structural diagram of the damping and buffering protection superstructure of the present invention.

[0014] Figure 2 FIG. is a schematic diagram of the energy band structure curve of the damping and buffering protection superstructure of the present invention.

[0015] Figure 3 FIG. is a graph of the wave attenuation coefficient under the combined action of the local resonance effect and the compression-torsion coupling mechanism.

[0016] Figure 4 FIG. is a response diagram of the superstructure under continuous harmonic vibration excitation.

[0017] Figure 5 FIG. is a response diagram of the superstructure under transient impact load.

[0018] In the figure: 1. Outer ring; 2. Connecting rod; 3. Resonant ball; 4. Middle ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] When conducting vibration isolation or anti-impact design in the prior art, often only the regulation of a single performance is achieved, and there are still deficiencies in promoting the simultaneous improvement of the two protection performances synergistically. The present invention combines the local resonance effect and the compression-torsion coupling mechanism to propose a new type of damping and buffering protection superstructure that combines the local resonance effect and the compression-torsion coupling mechanism, which is used to achieve vibration isolation and impact mitigation to achieve the effect of simultaneous protection against vibration and impact.

[0020] The following will further elaborate on the present invention in detail.

[0021] As Figure 1 shown, a damping and buffering protection superstructure based on local resonance and compression-torsion coupling includes a middle ring 4 and two compression-torsion tubes arranged in chiral symmetry with the middle ring 4 as the center; Each compression-torsion tube includes an outer ring 1 and six connecting rods 2, and the six connecting rods 2 are evenly arranged along the middle ring 4; Two outer circular rings 1 and a middle circular ring 4 are coaxially arranged; The connecting rod 2 is obliquely arranged, and its two ends are respectively connected to the middle circular ring 4 and the corresponding outer circular ring 1; Each connecting rod 2 is provided with a resonant ball 3. Preferably, the resonant ball 3 is embedded in the center of the connecting rod 2 to form a "spring - oscillator" system to promote the generation of local resonance effect.

[0022] According to Figure 1 the model diagram shown in, the aluminum alloy substrate is processed by additive manufacturing technology, and the superstructure is integrally directly 3D printed. When the superstructure is axially excited, due to the special deformation of compression - torsion coupling, the longitudinally incident longitudinal wave will be polarized into a torsional wave to achieve the purpose of isolating the propagation of the longitudinal wave. The resonant ball 3 further dissipates wave energy while generating the local resonance effect. Finally, a multifunctional effect of vibration and shock protection is achieved.

[0023] Compared with the traditional tube structure, when the superstructure of the present invention is invaded by vibration or shock, it will generate a local resonance effect and a compression - torsion coupling mechanism, and has a better and more stable wave energy dissipation efficiency. After passing through the chiral symmetric compression - torsion tube, the coupling of longitudinal and torsional deformation modes is realized, promoting the polarization of longitudinal waves and torsional waves. Therefore, a polarization band gap can be induced to block longitudinal waves. At the same time, the resonant ball 3 on the connecting rod 2 generates a significant local resonance effect, and the two can be ideally regarded as a "spring - oscillator" system to dissipate wave energy by local resonance. The vibration - damping and shock - buffering protection superstructure proposed by the present invention is mainly oriented to the application of comprehensive vibration and shock protection, that is, for continuous vibration isolation and instantaneous shock mitigation.

[0024] As Figure 2 and Figure 3 shown, in the range of 0 - 6500 Hz, due to the synergistic effect of the local resonance effect and the compression - torsion coupling mechanism, an ultra - wide longitudinal wave band gap in the range of 1700 - 6100 Hz and multiple local resonance modes are shown. In the longitudinal wave band gap range, multiple attenuation peaks are formed, and the maximum wave attenuation reaches - 108.66 dB.

[0025] Specifically, Figure 2Schematic diagram of the energy band structure curve of the vibration damping, buffering and protection superstructure of the present invention. In the frequency range of 0 - 6500 Hz, an ultra-wide longitudinal wave bandgap ranging from 1700 - 6100 Hz is generated. It indicates that longitudinal waves are polarized and attenuated within this frequency band range, and they undergo rapid exponential attenuation when propagating within the superstructure, forming an effect of isolating longitudinal waves. At the same time, within the frequency band where the bandgap is located, there are multiple nearly horizontal energy band curves, which indicates that the superstructure generates a local resonance effect at these frequencies, showing the same effect on wave attenuation in all directions, and the bandgap where it is located is a local resonance bandgap. Since the resonant ball 3 and the connecting rod 2 form a "spring - oscillator" system, wave energy is further dissipated here, and the wave attenuation ability is enhanced. The proposed superstructure generates an extremely wide bandgap in the low - frequency range, which is the result of the combination of the local resonance effect generated by the resonant ball 3 and the bandgap generated by the compression - torsion coupling mechanism of the chiral compression - torsion structure.

[0026] In addition to the energy band structure curve, the bandgap characteristics and wave attenuation ability can also be evaluated using the Figure 3 as shown wave attenuation coefficient curve. The definition of the wave attenuation coefficient is the logarithm of the ratio of the displacement at the response end of the superstructure to the displacement at the excitation end. The smaller the value of the wave attenuation coefficient, the greater the attenuation of the wave when propagating in the superstructure, and at the same time, its attenuation range also reflects the frequency range of the bandgap. Comparing the Figure 2 and Figure 3 longitudinal wave bandgaps, it can be found that within the frequency range of 0 - 6500 Hz, the attenuation coefficient curve shows significant attenuation within this frequency band, and the maximum attenuation coefficient is - 108.66 dB. At the same time, multiple sharp attenuation peaks are generated, and these sharp attenuation peaks represent the generation of the local resonance effect.

[0027] Figure 4 Shows the suppression of vibration propagation within and outside the bandgap under a continuous sinusoidal harmonic excitation signal, aiming to verify the vibration isolation characteristics of the superstructure for continuous harmonic excitation. Within the bandgap, the maximum displacement of the excitation is weakened from 1 mm to 0.32 mm. When the excitation frequency is outside the bandgap, as the harmonic excitation continues to act, the waves generated by the vibration continuously superimpose in the superstructure, and the energy of the waves continuously accumulates in the structure, and the response of the superstructure shows typical divergent characteristics. In sharp contrast, the excitation within the bandgap frequency range shows a significant vibration suppression effect. The maximum amplitude of the excitation signal is 1 mm, while the output response is effectively controlled within 0.32 mm, and the amplitude attenuation reaches 68%. This significant amplitude attenuation characteristic strongly confirms that the superstructure designed in this paper has excellent broadband vibration isolation performance.

[0028] Figure 5The impact mitigation capability of the superstructure to transient impact loads is described. Under the excitation of a transient impact load with an amplitude of 1 mm, the maximum displacement response within the band gap is only 0.1 mm, showing excellent impact mitigation capability. Time-history response analysis shows that under the same 1 mm amplitude pulse excitation, the excitation of the frequency band outside the band gap induces a significant dynamic response; while the excitation of the frequency band inside the band gap, due to the synergy of the local resonance effect and the compression-torsion coupling mechanism, the output response amplitude is effectively suppressed within 0.1 mm, achieving a dynamic attenuation rate of up to 90%. This amplitude attenuation characteristic spanning three orders of magnitude confirms that the superstructure has multifunctional protection performance of both broadband vibration isolation and transient impact protection.

[0029] The present invention uses a compression-torsion coupling mechanism and a "spring-oscillator" system composed of a connecting rod 2 and a resonant ball 3 to design a superstructure, on this basis forming a vibration isolation effect with strong wave attenuation capability and excellent impact protection, and achieving the effect of the two being achieved in coordination.

[0030] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A vibration damping, buffering and protective superstructure based on local resonance and compression-torsion coupling, characterized in that: It includes a middle ring and two piezotwist tubes arranged chiral symmetrically with the middle ring as the center; Each piezotwist tube includes an outer ring and a connecting rod; The outer ring and the middle ring are coaxially arranged; The connecting rod is inclined, and its two ends are respectively connected to the middle ring and the outer ring; There are multiple connecting rods, and the multiple connecting rods are evenly arranged along the middle ring; A resonant ball is threaded on each connecting rod.

2. The vibration damping, buffering and protecting superstructure according to claim 1, wherein: The resonant ball is embedded in the center of the connecting rod.

3. The vibration damping and buffering protection superstructure according to claim 1, characterized in that: In each piezotwist tube, the number of connecting rods is six.

4. The shock-absorbing and buffer protection superstructure according to claim 1, characterized in that: The vibration damping, buffering and protective superstructure is prepared by integral 3D printing.

5. The vibration damping, shock buffering and protective superstructure according to claim 1, wherein: The vibration damping, buffering and protective superstructure is processed with an aluminum alloy substrate.

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