Vibration Reduction Effect Research Articles

Research on Vibration Reduction in the Transmission System of Plastic Centrifugal Pump

The inherent weakness in the deformation resistance of plastic centrifugal pumps makes them prone to vibrations. This study explores the impact of flow components on the vibrations of such pumps. Utilizing the given parameters, the primary structural parameters of the plastic centrifugal pump were calculated. The study focused on the torsional vibrations within the pump shaft transmission system, employing a silicone oil damper for vibration mitigation. A dual-mass forced torsion vibration model was developed for the pump shaft transmission system with the added damper. The optimal damping coefficient for this damper was determined, and its structural design was completed, including the creation of three-dimensional models and two-dimensional part drawings. Utilizing a ZT-3 type rotor test bench, a mathematical model correlating centrifugal pump speed with deflection was developed, and the effectiveness of various polynomials was assessed. The analysis showed that the optimal damping value for the silicone oil damper is 0.22. Compared to the system without the damper, the vibration frequency reduced by 10.45%, and the vibration amplitude decreased by 49.29%, demonstrating excellent vibration reduction effectiveness.

Low-frequency bandgap characteristics and vibration attenuation performance of metamaterial-tailored concrete-filled steel tube columns

Low-frequency vibrations, such as earthquakes and wind loads, may negatively affect the proper operation of buildings and bridges and even lead to structural failure. Even though, in the past two decades, metamaterial-based structures have been utilized in structure vibration suppression, they are mainly used in the mitigation of high-frequency vibrations, and it has been an open challenge to suppress low-frequency vibrations below 100Hz and ensure adequate bearing capacity in engineering structures. In this work, we present metamaterial composite column structures with built-in local resonators to achieve the low-frequency vibration mitigation effect. Compared to ordinary concrete-filled steel tube (CFST) columns, the metamaterial columns (meta-columns) can utilize the rubber shear modulus to create a low-frequency flexural bandgap in 30–50 Hz. Dynamic stiffness is introduced in the Timoshenko beam and Bloch's theorem, the metamaterial analytical model is established, and the bandgap generation mechanism and vibration reduction effect are analyzed in conjunction with numerical simulations. Then, the bandgap effect and vibration attenuation law of the meta-columns are investigated by shaker tests at different acceleration amplitudes. Guided by theory and simulations, we have successfully fabricated several meta-composite columns with low-frequency bandgaps, which attenuate up to half of the vibrational energy near the bandgap center. The bandgap ranges derived from the theoretical and numerical models show a high degree of consistency with the experimental results, with deviations generally within 10 %, all indicating that a bandgap exists near the resonator self-oscillation frequency. Additionally, the bandgap is significantly affected by the number of unit cells and resonators, especially the meta-column with fewer resonators fails to form a bandgap where the top response is smaller than the bottom response. As the number of resonators and metamaterial units increases, the meta-columns exhibit wider bandgap and stronger vibration reduction performance.

Medium-high frequency vibration control of an industrial pipeline using squeeze-mode magnetorheological dampers

Due to fluid excitation and the vibration of connected equipment, industrial pipelines are prone to long-term medium-high frequency and small amplitude vibration. Magnetorheological (MR) dampers with a multi-stage squeeze plate structure were proposed to solve the problem of medium-high frequency vibration in the industrial pipeline. The dynamic characteristics of the industrial pipeline were analyzed to determine the installation position of the MR dampers. The mechanical properties of the proposed squeeze-mode MR dampers were tested, and the hyperbolic tangent mechanical model of the MR damper was established. The vibration control model of the industrial pipeline was built for simulation analysis. In addition, the Acceleration-Driven-Damper (ADD) control and the Proportional-Integral-Derivative (PID) control were used for simulation to predict the vibration reduction effect. Constant current experiments and control algorithm experiments were carried out on the vibration control platform of the industrial pipeline. The experimental results show that the maximum vibration attenuation rate of the MR dampers with constant current reaches 61.95%, while those with ADD control and PID control are 65.43% and 67.46%, respectively. Therefore, the squeeze-mode MR dampers can effectively reduce the medium-high frequency vibration of the industrial pipeline, and the control algorithms can further improve the vibration reduction performance.

Performance Analysis of a Vibration Absorber with the Inerter Element and Amplifying Mechanism

Based on the good performance of the new control elements, we introduce the viscoelastic model, the amplification mechanism and the inerter element into the dynamic vibration absorber (DVA). Then, we take it as the research object to obtain the DVA parameters when the system achieves the optimal vibration reduction effect based on the fixed-point theory. Finally, it is eventually demonstrated that the DVA discussed in this paper possesses significant benefits in mitigating vibrations, which provides theoretical basis and data support for the parameters design of DVAs in engineering application.

Seismic performance of soft rock tunnel under composite support conditions

In order to effectively improve the seismic and impact resistance performance of soft rock tunnels, a composite support method was proposed and validated in the paper. The UDEC (Universal Distinct Element Code) model of soft rock layers was established, and the movement and subsidence characteristics of the roof and floor of the rock layers under impact loads was simulated and calculated. As a result, a composite support scheme with good cushioning performance was proposed. The top and sides of the tunnel were supported by a combination of anchor rods of different lengths and metal mesh, reinforced by steel beams and vibration absorbing filler around. The anchor rod was designed as a segmented loading structure, and can be set to different preloading forces based on the internal deformation of the rock layer. The dynamic response testing scheme was designed, and the results indicate that the segmented loading anchor rod has a significant buffering effect on the response to impact load, and can provide reasonable tension feedback at different stages. Research has found that when the water cement ratio is 0.5-1.5, the curing efficiency and strength are both higher. In order to compare the seismic performance of composite support and traditional constant resistance anchor rod support, local blasting experiments were conducted. Based on a blasting vibration tester, a data detection and transmission system were designed to obtain the vibration speed of the tunnel roof during the vibration process. The research results show that composite support can reduce the maximum vibration by more than 40 %, stabilize the fragmentation coefficient at 1.38, and have a very significant vibration reduction effect.

Distributed control of a plate platform by NES-cells

Nonlinear energy sink (NES) has become a good passive vibration control technique with great potential. For a huge structure, it is unpractical to control the vibration by just one NES, let alone the structure has multi-modes. In this work, a technique who uses distributed nonlinear energy sink cells (NES-cells) to control the multi-modal resonance of the floating raft is proposed. The floating raft is simplified as a corner-point supported plate. Natural modes of it guide the distribution of NES-cells to make NESs locate on the position with strong vibration, which enhances the coupling ship between the plate platform and NES-cells. An example of installing NES-cells guiding by the first-two modes of the corner-point supported plate is presented in this paper. It is compared with the vibration reduction effect by a single NES. To make a fair comparison, total mass of NES-cells is the same with that of the single NES. The results show that NES-cells can deal with multi-modal vibration reduction better. The experimental results also fully illustrate this view. At the same time, the reaction of each NES-cell to the plate is effectively dispersed while comparing with the single NES, which decreases the stress at the attachment points and is more suitable for engineering applications. The number of NES-cells also has an effect on the vibration reduction efficiency. When the design parameters are fixed, there exists an optimal number to make the vibration reduction efficiency tend toward saturation. The multimodal vibration control of the plate platform is effectively solved by the proposed NES-cells technique. It also provides guidance for other practical engineering problems.

Experimental analysis of vibration and noise characteristics of helical gears with nano-lubricant additives

PurposeThe purpose of this study is to investigate the effects of nanoadditive lubricants on the vibration and noise characteristics of helical gears compared with conventional lubricants. The experiment aims to analyze whether nanoadditive lubricants can effectively reduce gear vibration and noise under different speeds and loads. It also analyzes the sensitivity of the vibration reduction to load and speed changes. In addition, it compares the axial and radial vibration reduction effects. The goal is to explore the application of nanolubricants for vibration damping and noise reduction in gear transmissions. The results provide a basis for further research on nanolubricant effects under high-speed conditions.Design/methodology/approachHelical gears of 20CrMnTi were lubricated with conventional oil and nanoadditive oils. An open helical gearbox with spray lubrication was tested under different speeds (200–500 rpm) and loads (20–100 N·m). Gear noise was measured by a sound level meter. Axial and radial vibrations were detected using an M+P VibRunner system and fast Fourier transform analysis. Vibration spectrums under conventional and nanolubrication were compared. Gear tooth surfaces were observed after testing. The experiment aimed to analyze the noise and vibration reduction effects of nanoadditive lubricants on helical gears and the sensitivity to load and speed.FindingsThe key findings are that nanoadditive lubricants significantly reduce the axial and radial vibrations of helical gears under low-speed conditions compared with conventional lubricants, with a more pronounced effect on axial vibrations. The vibration reduction is more sensitive to rotational speed than load. At the same load and speed, nanolubrication reduces noise by 2%–5% versus conventional lubrication. Nanoparticles change the friction from sliding to rolling and compensate for meshing errors, leading to smoother vibrations. The nanolubricants alter the gear tooth surfaces and optimize the microtopography. The results provide a basis for exploring nanolubricant effects under high speeds.Originality/valueThe originality and value of this work is the experimental analysis of the effects of nanoadditive lubricants on the vibration and noise characteristics of hard tooth surface helical gears, which has rarely been studied before. The comparative results under different speeds and loads provide new insights into the vibration damping capabilities of nanolubricants in gear transmissions. The findings reveal the higher sensitivity to rotational speed versus load and the differences in axial and radial vibration reduction. The exploration of nanolubricant effects on gear tribological performance and surface interactions provides a valuable reference for further research, especially under higher speed conditions closer to real applications.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2023-0220/

Design, Optimization, and Application of Nonlinear Energy Sink in Energy Harvesting Device

Vibration control has been of great interest to scientists and engineers for many years. Although linear vibration absorbers have been shown to be effective in mitigating vibrations at specific frequencies, their vibration reduction effect is usually limited to a narrow frequency bandwidth. Nonlinear energy sinks have attracted attention due to their better vibration reduction effect over a wider frequency bandwidth. In practical applications, the nonlinear energy sink devices can effectively absorb, dissipate, and convert energy from broadband excitation, so as to achieve vibration reduction and energy harvesting. However, research on energy harvesting based on the nonlinear energy sink is less mature than in linear systems. Multiple parameters of device design (e.g., damping size) affect the actual performance of the nonlinear energy sinks, but there is no exact method to simplify the design of the multiparameter nonlinear energy sinks. Since it is more difficult to implement electromagnetic and electrostatic energy harvesters, more research has focused on piezoelectric energy harvesters. This paper summarizes the research on the nonlinear energy sink and energy harvesting technology, including the introduction of the nonlinear energy sink, energy harvesting based on the nonlinear energy sink, and its application in various fields of energy harvesting. The paper also summarizes some important methods for solving the dynamical equations, as well as their advantages and disadvantages. The conclusions provide an outlook on the subsequent research of the nonlinear energy sink technology, such as the introduction of piezoelectric materials with high energy density, the benefits of balanced vibration suppression and harvesting of vibration energy, and the self-tuning of parameters in complex environments. It provides a powerful reference for the popularization and application of energy harvesting technology based on nonlinear energy sinks.

钢弹簧浮置板轨道减振效果现场与实验室测评研究

钢弹簧浮置板轨道减振效果现场与实验室测评研究

Surrogate model-based multi-objective design optimization of vibration suppression effect of acoustic black holes and damping materials on a rectangular plate

The acoustic black hole (ABH) is a ground-breaking passive technology for vibration reduction and noise attenuation, characterized by its ability to manipulate flexural waves. When multiple two-dimensional ABHs are embedded in an irregular shaped complex plate structure used in engineering, such as the support plate of a refrigerator compressor, its vibration characteristics often cannot be solved through analytical or semi-analytical methods, resulting in the inability to carry out subsequent ABH optimization design. To address this issue, we propose a high-precision modelling method that combines surrogate models with finite element methods to construct a vibration characteristic database of the compressor support plate embedded with multiple ABHs in all design spaces of the ABH and damping materials geometric parameters using limited sample data. A high-precision surrogate model was constructed based on the vibration response data of the ABH plate under 50 parameter combinations of ABH and damping layer, and the fitting accuracy of the surrogate model was verified through vibration response data under another 25 parameter combinations. Based on the constructed surrogate model, the Multi-objective Genetic Algorithm (MOGA) was employed to optimize the five parameters of ABH and damping layer simultaneously, aiming to maximize the vibration reduction effect of the ABHs. Our investigation reveals that the optimized ABH and damping materials significantly improve the vibration suppression effect in a wide frequency range compared to the unoptimized structures. Finally, experimental verification was conducted to solidify the accuracy and efficacy of our approach in enhancing vibration reduction effect for irregular shaped complex plate structures using acoustic black holes.

Dynamic Characteristics and Optimization of Segmented Fork Arm Seat System

To improve the low-frequency vibration isolation performance and driving comfort of the engineering seat system, a segmented fork arm seat system is proposed. Firstly, the equivalent model of the n-level segmented seat system is established, the amplitude-frequency response function and phase-frequency response function of the segmented seat system are solved and analyzed. The theoretical study shows that, with the increase of segment levels, the response time of the seat system is shortened, and the attenuation rate of response amplitude is accelerated; with the increase of segment levels, the resonance peak value of the seat system tends to shift continuously, and the low-frequency vibration isolation range expands. Secondly, according to the actual application condition of a loader, the engineering structure of the 3-level segmented fork arm seat system was built, and the structure-stiffness parameters of the segmented fork arm seat system were optimized by multi-objective genetic algorithm. The optimization results show that the 3-level segmented fork arm seat system has obvious vibration reduction effect on the sensitive frequency band of the human body. The vibration reduction effect on road excitation increases by 63.2% on average under driving conditions, 75.8% on uneven road surface, and 65.2% under operating conditions, and the subjective comfort evaluation index of human body increases by two levels.

Low frequency vibration reduction bandgap characteristics and engineering application of phononic-like crystal metaconcrete material

Metaconcrete, as a new type of composite material with vibration attenuation characteristics, is formed by replacing traditional coarse aggregates with a heavy metal core wrapped with an elastic soft coating and mixing with cement mortar. However, due to the high bandgap frequency and narrow bandgap width, it is greatly limited in the engineering application of low frequency vibration control. In order to broaden the range and number of elastic wave bandgap of metaconcrete materials and solve the problem of low frequency vibration, a novel three-component cement-based phononic-like crystal model is proposed based on local resonance theory, and phononic-like crystal metaconcrete vibration reduction material is developed accordingly. Secondly, the band structure, bandgap mechanism, and frequency response function of the phononic-like crystal metaconcrete are calculated and analyzed, and indoor tests of the phononic-like crystal metaconcrete are conducted. Finally, a phononic-like crystal metaconcrete subway track bed is prepared using the developed phononic-like crystal metaconcrete material, and applied to the practical subway engineerings to solve the low frequency vibration problem generated during subway operation. The results show that the phononic-like crystal metaconcrete opens 6 low frequency bandgaps in the frequency range of 200 Hz, and the attenuation values are mostly above 10 dB in the frequency range of the bandgap, and the attenuation effect is good. Meanwhile, the on-site monitoring results show that the phononic-like crystal metaconcrete subway track bed has good low frequency vibration reduction effect in the 200 Hz frequency range. The maximum value of the one-third octave insertion loss of the tunnel wall is 13.22 dB, the maximum vertical Z-vibration level difference of the tunnel wall is 5.052 dB, and the maximum vertical frequency division vibration level difference of the tunnel wall is 5.926 dB. The maximum value of the vertical frequency division vibration level difference in the frequency range of 4–200 Hz is 13.87 dB, and the average value is 5.74 dB. The relevant research results of this paper provide a new technical approach to solve the problem of low frequency vibration in subway engineering and other engineering construction, breaking through the traditional vibration reduction control technology of civil engineering structures, and providing new idea and method for long-term vibration reduction and application of engineering structures.

Vibration Suppression Study of Parallel Combined Damping Nonlinear Energy Sink on Piecewise Linear Systems

The Nonlinear Energy Sink (NES) is a passive control device capable of achieving targeted energy transfer and effectively suppressing system vibrations. This paper conducts dynamic modeling and vibration suppression analysis of parallel combined damping nonlinear energy sinks in piecewise linear systems. Initially, the system's amplitude-frequency response curve is obtained using the harmonic balance method, validated by the Runge-Kutta method for accuracy. Subsequently, an analysis is performed on the vibration reduction capabilities of the parallel combined damping nonlinear energy sink and the influence of parameters on its vibration suppression effectiveness. Finally, the study investigates changes in the main system's maximum response amplitude with varying damping under different stiffness conditions and determines optimal parameter values based on trend analysis. Research findings indicate that the vibration reduction performance of the parallel combined damping nonlinear energy sink surpasses that of a single connected damping nonlinear energy sink. Furthermore, after parameter optimization, the main system achieves superior vibration reduction effects.

Research on the effect of rail vibration suppression using the stiffness-damping interventional rail vibration reduction device

This study introduces the Stiffness-Damping Interventional Rail Vibration Reduction Device (SDIRVRD) as a means to enhance rail vibration suppression. It compares the SDIRVRD with the traditional tuned rail damper (TRD) in terms of their vibration suppression mechanisms. The research investigates the influence of the SDIRVRD’s stiffness and damping parameters on the dynamic response of the vehicle and track. It also conducts a comparative analysis of track and vehicle vibration responses before and after the installation of the SDIRVRD, evaluating its effectiveness in reducing both track system and vehicle vibrations. The field test validates the theoretical calculations, and the vibration reduction efficiency is quantified using the insertion loss value. Key findings include the superiority of the SDIRVRD over the TRD in vibration reduction under equivalent damping ratio conditions. The SDIRVRD significantly reduces rail acceleration, displacement, and velocity admittances, with a notable suppression effect on pinned-pinned rail vibration. The stiffness and damping of the SDIRVRD play a crucial role in enhancing its vibration reduction effect, but after the stiffness exceeds 2 kN/mm and further increases the stiffness of the SDIRVRD, the enhancement of its damping effect on the vehicle-track system’s vibration diminishes significantly. The SDIRVRD reduces acceleration vibration levels in the vehicle and track system by approximately 2–3 dB. Insertion Loss measurements show significant vibration reduction in the rail across most frequency domains.

Acoustic characteristics of composite structures with 2D acoustic black holes and stiffened plates

Acoustic black hole (ABH) structure, a novel technology for modulating flexural waves, offers promising solutions for controlling noise caused by structural vibrations. In this paper, we introduce acoustic black holes into traditional stiffened plate structures and design a new type of ABH stiffened plate structure, which combines the wave manipulation ability of ABH with the load-bearing capacity of the stiffened structures. We establishes finite element models for calculating the free space sound field and closed cavity sound field of an ABH stiffened plate, builds corresponding experimental platforms, and tests them under point load excitation. The results show that ABH stiffened plate has great vibration and noise reduction effects, with a 5–10 dB reduction in sound radiation power above the cut-on frequency and a maximum noise reduction of about 30 dB. Through quantitative analysis from multiple perspectives, it is shown that ABH have an inherent mechanism of increasing damping level and reducing coupling between structure and sound field. Studying the influence of different media on the acoustic radiation of ABH stiffened plates, results further reveal that ABH have noise reduction effects in water media, and increasing the application scenarios of the ABH stiffened plate structures.

Periodic motion and optimization design of non‐stacked particle damper based on the double inert mass equivalent model

AbstractTo promote the application of non‐stacked particle damper (NSPD) in civil engineering, a design methodology was suggested on the basis of the double inert mass equivalent model. NSPD single‐story steel frame model is selected as the research object in this paper. First, the analytical solution for the periodic motion with symmetric two impacts was discussed. The shaking table test was performed to verify the rationality of the analytical solution under harmonic excitation. Subsequently, based on the analytical solution, the influence of equivalent connection stiffness on the vibration reduction effect and mechanism was analysed under resonant and non‐resonant harmonic excitation. The numerical analysis methods of the optimal equivalent connection stiffness were obtained accordingly. Finally, the effectiveness and generalization of the proposed optimal equivalent connection stiffness were discussed numerically under harmonic excitation and seismic ground motion. An optimal design process for the NSPD was proposed accordingly. Based on this, the vibration reduction performance analysis of NSPD under far‐field records, near‐fault pulse‐like records and near‐fault non‐pulse records was further conducted in the end. The results show that the time‐dependent frequency behaviour of the uncontrolled structure has a significant impact on the performance of the NSPD. The proposed optimization method is effective, which can be used as the foundation for the optimization of NSPD under earthquakes.

Dynamic response analysis of piled embankment and train derailment evaluation subjected to seismic and high-speed train loads

Based on a train-rail-piled embankment three-dimensional finite element model, the vibration displacement, acceleration and frequency spectrum of the rail and subgrade caused by combined seismic and high-speed train loads was investigated. On this basis, performance of piled embankment under combined seismic and high-speed train loads was analyzed. Numerical examples indicate that the seismic load dominates the ground displacement and the moving train load has negligible effects on the ground displacement. However, the moving train load has a significant effect on the rail vibration displacement during earthquakes. The rail and subgrade vibration displacement of piled embankment under combined seismic and moving train loads is obviously lower than that of ordinary subgrade, and its dominant frequency tends to transfer from high to middle and low frequency compared with ordinary subgrade, indicating that pile embankment has a good vibration reduction effect. Moreover, the derailment coefficient and lateral displacement of piled embankment is obviously decreased, which provides important guidance that pile embankment has significant vibration reduction effect and thus it can effectively prevent derailment or overturning during earthquakes.

Numerical analysis of the effect of trench on indoor vibration adjacent to railway ground line

By establishing a 3D finite element numerical simulation analysis model of railway-soil-trench-building, the accuracy of the simulation analysis model is verified using on-site measured data of surface vibration attenuation law. Install vibration isolation trenches with different depths at different locations between the building and the railway, and analyze and compare the impact of indoor vibration in different situations. The results indicate that; The surface vibration caused by railways attenuates rapidly around 30m~76m from the line, and then shows a slight amplification trend around 120m. The surface vibration near the railway is mainly concentrated in the range of 15-90Hz; The vibration reduction effect of trench on different indoor rooms in buildings varies greatly. By optimizing the parameters of trench, the average indoor vibration reduction effect can be close to 5dB, and the vibration reduction effect of trench at different positions varies greatly. The increase in trench from 6m to 12m increases the indoor vibration isolation effect.

Active vibration control for reduction of interior noise caused by R-MDPS

This paper presents an active vibration control (AVC) to reduce the vibration of motor driven power steering (MDPS). The MDPS used in the experiment was R-MDPS, an MDPS connected to Rack Gear. When the R-MDPS generates vibration in the operating state, the vibration is transmitted through the subframe. The vibration transmitted through the subframe generates indoor noise and reduces the driving quality of the driver. To reduce vibration, the AVC was used by inserting an actuator between R-MDPS and subframe. The actuator used Piezo material is called a Piezo actuator. To select the location of the actuator, Transfer path analysis (TPA) was performed. the effect was confirmed by setting the main path to error point. The experiment was conducted for feasibility by connecting R-MDPS and subframe to a test bench manufactured in the laboratory. The algorithm used for vibration control used the Filtered-X Least Mean Square (FxLMS) algorithm and the control result was reduced from 4 to 5 dB. It is shown that proposed method is an effective vibration reduction effect of R-MDPS.

A new mesh-type rail pad with second-order stiffness

In this paper, a novel mesh-type rail pad with second-order stiffness (MTRPSOS) is proposed, which is comprised of a mesh-type rail pad (MTRP) and multiple filled blocks. By adjusting the height of the filled blocks, the stiffness curves of the MTRPSOS exhibit pronounced second-order stiffness (SOS) characteristics. A finite element (FE) model of the MTRPSOS and a dynamic model were established to investigate the SOS characteristics and their impact on various dynamic indices. The FE calculations reveal that both static and dynamic stiffness of the MTRPSOS increase as the height of the filled blocks decreases. Moreover, as the height of the filled blocks increases, stress distribution becomes more uniform. The dynamic calculations demonstrate that the SOS characteristics of the MTRPSOS significantly affect various dynamic indices. As the SOS of the MTRPSOS decreases, rail displacement correspondingly increases, while vibration acceleration, wheel-rail forces, fastener reaction forces, and derailment coefficient all decrease. This indicates that the MTRPSOS offers superior vibration reduction under the SOS conditions compared to the first-order stiffness conditions. Additionally, a comparative study was conducted to assess the vibration reduction effect of the MTRPSOS in contrast to traditional rail pad, and the results show that the MTRPSOS consistently exhibits lower vibration levels under the same operating conditions, underscoring its superior capacity for vibration reduction.