Particle Damping Research Articles

Influence of cavity partition on the damping performance of additively manufactured particle dampers

Additively manufactured particle dampers (AMPDs) are innovative particle dampers created by intentionally preserving unfused powder within a structure during laser powder bed fusion. One of their distinct advantages is the ease of fabricating structures with multiple cavities. This study focused on exploring the influence of cavity partitioning on the damping capacity of AMPDs at five different frequencies (200, 500, 1000, 1500, and 2000 Hz) and an acceleration range of 50–250 m/s2. Five AMPDs were designed to have similar cavity ratios while differing in cavity size. A complex power experiment and discrete element model simulation analysis were carried out. Notably, a consistently larger clearance between the ceiling of the wall and the powder bed was observed in the AMPDs with larger cavity sizes. Furthermore, dividing a larger cavity of AMPD into several smaller cavities emerged as an effective approach to maintain the damping performance at higher frequencies.

Additively manufactured structures with powder inclusions for controllable dissipation: The critical influence of packing density

Particle dampers represent a simple yet effective means to reduce unwanted oscillations when attached to structural components. Powder bed fusion additive manufacturing of metals allows to integrate particle inclusions of arbitrary shape, size, and spatial distribution directly into bulk material, giving rise to novel metamaterials with controllable dissipation without the need for additional external damping devices. At present, however, it is not well understood how the degree of dissipation is influenced by the properties of the enclosed powder packing. In the present work, a two-way coupled discrete element - finite element model is proposed allowing for the first time to consistently describe the interaction between oscillating deformable structures and enclosed powder packings, while existing works have only considered rigid enclosures so far. As fundamental test case, the free oscillations of a hollow cantilever beam filled with various powder packings differing in packing density, particle size, and surface properties are considered to systematically study these factors of influence. Critically, it is found that the damping characteristics strongly depend on the packing density of the enclosed powder and that an optimal packing density exists at which the dissipation is maximized. Moreover, it is found that the influence of (absolute) particle size on dissipation is rather small. First-order analytical models for different deformation modes of such powder cavities are derived to shed light on this observation.

Analysis of vibration reduction performance of vibration isolation system based on particle damping

Taking ship vibration isolation systems as the research subject, the particle damper was applied to ship vibration isolation systems to study its vibration reduction performance. The energy dissipation mechanism of particle dampers is analyzed, and an energy dissipation calculation model is derived. The combined method of simulation and experimentation is employed to study the influence of parameters such as particle material, filling rate, particle diameter, and collision coefficient of restitution on the vibration reduction performance of particle dampers. The impact laws of these parameters are summarized, demonstrating that particle dampers can produce excellent vibration reduction performance when applied in ship vibration isolation systems, and reasonable parameter recommendations are provided. Response surface method (RSM) is used to fit an accurate energy dissipation prediction model and calculate the optimal performance parameters. This paper serves as a valuable reference for the parameter design, optimization, and practical engineering applications of particle dampers.

Collaborative Design of Static and Vibration Properties of a Novel Re-Entrant Honeycomb Metamaterial

A novel re-entrant honeycomb metamaterial based on 3D-printing technology is proposed by introducing chiral structures into diamond honeycomb metamaterial (DHM), named chiral-diamond-combined honeycomb metamaterial (CDCHM), and has been further optimized using the assembly idea. Compared with the traditional DHM, the CDCHM has better performance in static and vibration isolation. The static and vibration properties of the DHM and CDCHM are investigated by experiments and simulations. The results show that the CDCHM has a higher load-carrying capacity than that of the DHM. In addition, the vibration isolation optimal design schemes of the DHM and CDCHM are examined by experiments and simulations. It is found that the vibration suppression of the CDCHM is also improved greatly. In particular, the optimization approach with metal pins and particle damping achieves a wider bandgap in the low-frequency region, which can strengthen the suppression of low-frequency vibrations. And the introduction of particle damping can not only design the frequency of the bandgap via the alteration of the dosage, but also enhance the damping of the main structure. This work presents a new design idea for metamaterials, which provides a reference for the collaborative design of the static and vibration properties of composite metamaterials.

Dynamic analysis and experimental investigation of particle damping for the vibration reduction and isolation of floating raft using the two-phase flow theory of gas-particle

ABSTRACT To ensure an effective and smooth operation of shipborne equipment and show ships’ vitality, the floating raft is universally used to reduce mechanical vibration and underwater-radiated noise. However, the vibration amplification phenomenon still occurs in low-frequency excitation of shipborne equipment. Accordingly, a new idea for enhancing vibration reduction and isolation performance of floating rafts for shipborne equipment based on particle damping is proposed. Considering particle-particle frictions and collisions inside the damper, a mathematical model of particle damping using the two-phase flow theory of gas-particle is derived for the dynamic analysis combined with the finite element method. The damping effect for vibration reduction is obtained by dynamic analysis with different dampers-installation schemes in raft structures. An experimental platform for the floating raft with particle dampers is built. Comparing its dynamic analysis with experimental investigation results, the rationality and feasibility of the mathematical model of particle damping are demonstrated. In addition, this research further indicates that particle damping enhances the vibration isolation performance of floating rafts in low-frequency excitation for shipborne equipment, which is of great practical significance to improve the combat effectiveness of ships.

Experimental study on damping characteristics of the particle dampers with damping rod and soft inside wall

In the perpendicular simple sinusoidal excitation, the damping characteristics of the soft-wall particle damper with a damping rod were experimentally investigated by controlling the acceleration amplitude and vibration frequency of the damper motion and measuring the force and acceleration signals. The experimental results show that the loss power of the damper increases monotonically with the rise of the excitation acceleration amplitude, and the effective mass shows the change of “gentle decrease-critical point-decrease”. As the driving frequency rises, the loss power progressively decreases, and the effective mass does not change significantly. By analyzing the damping characteristics of different dampers, it shows that the damping effectiveness of the soft inside wall particle damper with a damping rod is obviously better.

Co-Design of Mechanical and Vibration Properties of a Star Polygon-Coupled Honeycomb Metamaterial

Based on the concept of component assembly, a novel star polygon-coupled honeycomb metamaterial, which achieves a collaborative improvement in load-bearing capacity and vibration suppression performance, is proposed based on a common polygonal structure. The compression simulation and experiment results show that the load-bearing capacity of the proposed metamaterial is three times more than that of the initial metamaterial. Additionally, metal pins are attached and particle damping is applied to the metamaterial to regulate its bandgap properties; the influence of configuration parameters, including the size, number, position, and material of the metal pins, on bandgaps is also investigated. The results show that the bandgap of the proposed metamaterial can be conveniently and effectively regulated by adjusting the parameters and can effectively suppress vibrations in the corresponding frequency band. Particle damping can be used to continuously adjust the frequency of the bandgap and further enhance the vibration suppression capacity of the metamaterial in other frequency bands. This paper provides a reference for the design and optimization of metamaterials.

Effects of particle damper design parameters on the damping performance of laser powder bed fused structures

Particle dampers (PD), a passive damping technology, absorb energy from particle-particle and particle-cell wall interactions originating from friction and collision. PDs offer advantages such as design simplicity, low cost, applicability in harsh conditions, and flexibility to be used in a wide frequency band range. Additive manufacturing, specifically the powder bed fusion process, can fabricate structures with integrated PDs in a single printing process, eliminating the need to implement external dampers. However, the dynamic behavior of PDs must be determined to utilize their full potential. In this study, we examined 16 cases of integrated PDs by varying specific parameters including size, number, and locations on the structure to understand the effects of these parameters on the dynamic behavior of the first and second modes of the structure. Modal tests were conducted on additively manufactured samples to extract frequency response functions and calculate modal parameters (natural frequency and damping ratio) using the rational fraction polynomial method, studying the effects of PDs. The results showed that the damping performance of the parts was increased by a factor of up to 10 using body-integrated PDs compared with the fully fused specimen. The effectiveness of body-integrated PDs was shown to be strongly dependent on their volume and location. For instance, the damping generally increased as the volume fraction increased, which also reduced the total weight of the specimens by up to 60 g. Furthermore, the damping performance significantly increased for a specific mode when the PDs were located near the maximum displacement regions.

Review of Lightweight Vibration Isolation Technologies for Marine Power Devices

Vibration induced by marine power devices (MPD) transmitting to the hull structure is one of the most important factors that cause ship vibration and underwater sound radiation. Vibration isolation technologies (VIT) are widely applied to reduce the vibration transmission. However, the overweight issue of VIT for marine power devices is a currently challenging engineering problem. The current reserve of lightweight and high-efficiency VIT for MPD and relevant theoretical and design research are seriously insufficient. This article first elaborates the causes of the overweight problem of VIT for MPD: (1) failing to grasp the quantitative law; (2) single vibration suppression mechanism. Then, it systematically sorts out the technical methods and application examples with potential to solve the overweight problem, such as dynamic optimization design, lightweight material method, novel intermediate mass structures, distributed dynamic vibration absorbers (DDVAs), locally resonant structures (LRS), particle damping (PD), quasizero stiffness isolators (QZSI), and active vibration control (AVC) technologies. Finally, the future development of lightweight VIT for MPD is prospected. It can be used as a reference for marine vessel vibration attenuation research and engineering design.

Optimal positioning and distribution of magnetorheological damper

During seismic events, devices are used to disperse energy in buildings, reducing structural damage and preventing collapse. One such device is the magnetically polarizable particle damper, consisting of a hydraulic cylinder filled with magnetically responsive particles in fluid. Recent research optimized damper placement and distribution using detailed mathematical modeling and mode shapes covering over 95% of the building's mass. Researchers identified critical damper positions by correlating these models with maximum force functions in the equations of motion. The study proposed a positioning strategy to reduce costs associated with damper installation in typical building practices. The number of dampers required varied with applied loads: 20kN, 30kN, 90kN, and up to 200kN. For instance, under 20kN and 30kN loads, optimal distribution included assigning 8 dampers to the ground, first, second floors, decreasing to 4 on floors three and four, and 2 on the fifth floor, totaling 14 and 20 dampers, respectively. Optimization values for these loads were calculated at 17.71. Dealing with a 90kN load required 44 dampers, distributed as 8 on lower levels, 4 on the third floor, and 8 each on floors four and five. Remarkably, while 20kN and 30kN damper counts reduced, 24 were added for 90kN, yielding an optimization score of 45.84. For a 200kN load, 17 dampers were strategically allocated, with specific placements adjusted per floor, achieving an efficiency score of 49.616. This underscores the effectiveness of the chosen damper arrangement in bolstering structural resilience against seismic forces.

Research on Loss Characteristics Based on the Vibration Law of Granular Assembly

Particle damping technology is a typical passive vibration damping technology. In order to further explore the energy dissipation characteristics of particle dampers under different excitation, the relationship between internal vibration state and energy dissipation is analyzed. Based on the analysis of the motion state of granular assembly inside three‐dimensional cylindrical particles, the steady‐state energy flow method is used to study the loss characteristics of the granular assembly with different vibration laws. The research is carried out under the condition of excitation reduced acceleration of 0–8 and excitation frequency of 0–300 Hz. The results show that the loss capacity of the particles is enhanced when the vibration state of the particles changes from solid‐like to other motion states. At frequencies above 250 Hz, the particle microvibrational and intermediate‐vibrational loss effects are more significant. The loss capacity of the granular assembly shows frequency‐dependent characteristics and is affected by frequency and reduced acceleration. With the increase of the reduced acceleration, the loss capacity of particles is enhanced and shows a local peak effect as the frequency increases. The increase of the particle size enhances the loss ability in the microvibrational state and the intermediate‐vibrational state. By changing the vibrational state, the energy dissipation capacity of particle damper can be enhanced, which may provide a new idea for designing optimal granular dampers.

Mechanism and Experimental Investigation of Vibration Reduction for Container Cranes Based on Particle Damping Technology

Container cranes have been widely used for port operation. However, the structure of the port container crane is large, which always leads to crane damage under vibration and strong wind. Therefore, a method for vibration reduction of container crane structure based on particle damping technology is proposed. In this investigation, the scale 1:80 crane model is built, and the equivalent mechanical model is also established to preliminarily verify the effect of vibration suppression. Furthermore, the dependence of vibration suppression effect on the key parameters of the damper, i.e., filling material, filling rate, particle size, and installation position of dampers are analyzed through experiments. The results indicate that the vibration peak of the crane structure displayed in the Simulink oscilloscope is weakened and lags behind, the installation of the damper brings the effect of vibration suppression for the crane, and the vibration suppression effect reaches 25%; the crane mode obtains the best vibration suppression effect under the condition that the material filled in the damper has a large density and elastic modulus, sufficient collision space and high collision frequency, and the dampers are installed far away from the crane center of gravity. The optimum parameters of the damper obtained from experiments were 12 mm lead beads, a filling rate of 60%, installed in the distal ends within the strength range of the forearm of the crane. It is thus concluded that particle damping technology has provided an effective way of wind and vibration reduction for container cranes.

Design Strategies of Particle Dampers for Large-Scale Applications

Abstract Purpose Particle dampers are dynamic vibration absorbers that can be attached or inserted into a vibrating structure for broadband vibration attenuation. The particle damping technique is widely used across various industries for vibration attenuation because of its conceptual simplicity, cost-effectiveness, and suitability for harsh environments (Gagnon et al. in J Sound Vib, 2019. https://doi.org/10.1016/j.jsv.2019.114865; Lu et al. in Struct Control Health Monit, 2018. https://doi.org/10.1002/stc.2058). However, designing a particle damper for real-world applications is significantly challenging primarily due to the interaction among the numerous parameters that influence the damping effectiveness of a particle damper. Therefore, this contribution aims to experimentally investigate the particle dampers performance in the context of their designs. Methods We introduce three different design variants, namely thin-walled cavity (TWC), thin-walled cavity with additional sheets (TWC-AS), and ring cavity (RC). Different strategies are detailed and evaluated in the current paper. Following the comprehensive study of various design variants at the laboratory scale, several tests were conducted on a real-scale wind turbine generator, subjected to real-world loading conditions. Additionally, the effect of particle damper size and its location for the structure on vibration attenuation has been studied. Results Based on the experimental investigation, all these variants are effective in reducing the vibration amplitude of a structure. Furthermore, it has been found that for practical applications, particularly in the case of large-scale mechanical structures such as wind turbines, it is advisable to combine the most successful variants to design a particle damper. This approach can achieve significant vibration attenuation, and also minimize the additional mass of the granular material compared to a conventional particle damper. Conclusion The findings from our experimental studies offer valuable insight into the design of particle dampers for large-scale hollow mechanical structures.

Modeling of the hysteretic behavior of nonlinear particle damping by Fourier neural network with transfer learning

The particle damper (PD) filled with granular material exhibits hysteretic behavior under dynamic excitation, meaning that its response depends not only on the current excitation but also on its excitation history. The hysteresis loops of a PD vary with the excitation frequency due to its nonlinear nature. To model the particle damping hysteresis, this study proposes using neural networks (NN), which have a powerful ability to recognize such nonlinear relationships. However, NNs suffer from a long-standing issue called spectra bias, which means they tend to learn low-frequency components first and struggle to recognize high-frequency components. This is a problem for modeling PDs, which may involve high-frequency features in the target function. To address this issue, the recently developed theory of neural tangent kernel (NTK) revealed why NNs are perplexed by the spectra bias. Based on this theory, Fourier features embedding is proposed to expedite the learning of NNs on high-frequency features to extricate NNs from the shackle of spectra bias. After implementing the Fourier features embedding, an investigation on the use of transfer learning (TL), incorporated with the physics-informed neural network (PINN), is conducted to improve the proposed model’s performance. The concatenation of Fourier features embedding and TL formulates the proposed method, the Fourier features-embedded, transfer learning-incorporated physics-informed neural network (ff-TLPINN).The established surrogate model of the PD’s hysteretic response force under steady-state excitation covers a wide frequency range of 100–2000 Hz. The proposed model is validated using a dataset generated from the sweep-sinusoidal excitation and is shown to be more effective than a plain NN model. The study’s findings demonstrate the potential of using NNs to model the hysteresis of PDs and the effectiveness of using Fourier features embedding and TL to overcome the issue of spectra bias and improve the model’s performance. Overall, the proposed model provides a promising approach to accurately modeling the behavior of granular material-dilled PDs under dynamic excitation.

Numerical and Experimental Investigations of Particle Dampers Attached to a Pipeline System

The structure of pipeline systems is complex, and the working environment is harsh. Under the excitation of the engine equipment foundation and pump fluid, it is easy to generate excessive vibration, which seriously affects the safe operation of the equipment. Particle damping achieves structural vibration suppression through the principle of particle collision dissipation. Due to the drawbacks of traditional pipeline vibration reduction methods, this article introduces a particle damping technology for pipeline system vibration suppression and designs particle dampers based on the structural characteristics of pipelines. We analyzed the energy dissipation mechanism of particle damping, revealed the influence of the materials, structure, external excitation, and other parameters of the pipeline particle dampers on the energy dissipation characteristics of the particle damping, established a pipeline vibration reduction test system with particle damping, and verified its effectiveness in pipeline system vibration reduction. This study can provide a technical reference for vibration reduction in pipeline systems.

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.

Research on low frequency noise reduction device for substation equipment

Aiming at the pain point that it is difficult to control the low-frequency noise of the substation equipment, a new noise reduction method is proposed. It can reduce the noise propagation of the equipment without changing the structure of the equipment. The discrete element model of particle dampers for substation equipment is established. The energy consumption value of the particle system is used as an evaluation index. It optimizes parameters such as filling rate and particle size and determines the parameters of the scheme with the best damping effect. Through the combination of simulation and test, the test prototype was built to verify the effect. The test data showed that the total noise extremes of the first and second-floor measurement points were reduced by 14.55 dB and 6.99 dB, respectively, after installing the particle damper. This solution adds a new means of low-frequency noise control for substation equipment.

Experimental and Numerical Investigation of the Damping Performance of Metal Additively Manufactured Particle Damper

The additively manufactured particle damper (AMPD) is a novel particle damper fabricated by leaving unfused powder inside the pre-designed structural cavities during the laser powder bed fusion (LPBF) process. It can be applied at high temperatures and a wide range of frequencies without any additional installation space. However, the damping mechanism and performance of AMPD are still unclear due to insufficient experimental and simulation analyses. In this work, the damping capacity of AMPDs with three different unit cell sizes at high frequencies and low vibration amplitudes were investigated experimentally and numerically. The AMPDs were manufactured using LPBD with 316 L stainless steel. The complex power method was used to measure the energy dissipation of the AMPD directly. A discrete element method (DEM) simulation model was developed to visualize the particle motion mode during each vibration process. The computed tomography (CT) pictures were utilized to measure the powder distribution in each AMPD's cavity. Finally, the influence of excitation frequency, excitation amplitude, and cavity size on the damping performance of the AMPD were explained by comparing the experimental and simulation results.

Variable stiffness tuned particle dampers for vibration control of cantilever boring bars

Variable stiffness tuned particle dampers for vibration control of cantilever boring bars

Optimization performance for a combined damping system with a TMD and a multiple unidirectional single particle damper

This research systematically assessed the optimization performance of a combined damping system (CTP) with a Tuned mass damper (TMD) and a multiple unidirectional single particle damper (MUSPD). Firstly, the impact force between the controlled structure and the particle was equivalent to the pulse force, leading to the development of an equivalent mechanical model for the CTP. Subsequently, this model was solved analytically using a blend of frequency domain and time domain methods. Secondly, building upon the analytical solution, a method for optimizing the CTP subjected to both harmonic excitation and ground motions was proposed. Thirdly, the simulation of the CTP validated the accuracy of the equivalent mechanical model and demonstrated the practicality of the optimization method. Finally, a comparative analysis of the optimal performance among the MUSPD, TMD, and CTP was presented. The results indicate that the equivalent mechanical model for the CTP not only facilitates solving dynamic responses but also delineates its damping mechanism. The simulation and theoretical comparison results of CTP indicate that the equivalent mechanical model has good accuracy and the optimization method has good rationality. Subjected to resonant harmonic excitation, the CTP exhibited a damping rate of 94.90% for peak displacement and 96.17% for RMS, while subjected to ground motions, it maintained an average damping rate of 24.16% for peak displacement and 48.67% for RMS. The CTP delivers superior damping effects, a broader suppression frequency band, and heightened robustness compared to the MUSPD and TMD.