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.
•Experimental and DEM studies of granular dampers that use spheroidal particles.•Evaluation of particle shape dependency in the optimum, bouncing bed phase.•Reduced sphericity found to increase the ...amplitude at which the optimum occurs.•Observed characteristic linked with material properties and packing parameters.
This paper presents new research to determine the effect of particle shape on the energy dissipation in a granular damper operating in the bouncing bed motional phase. This is accomplished by conducting controlled experiments and validated Discrete Element Method (DEM) simulations for a broad collection of spheroidal particle shapes at vibration amplitudes of up to 50 g. The findings show that non-spherical particles significantly change the condition known as the “bouncing bed onset amplitude” which is the vibration amplitude at which granular damping is maximised. It is shown that the packing parameter known as the coordination number is an indicator of this change and that there is a correlation between the shear properties of the granular medium and the amplitude at which it delivers optimum energy dissipation. This paper also presents a sensitivity analysis specific to the bouncing bed phase which considers variations in particle modulus, density, restitution coefficient and friction. This shows that the observations about the effects of particle shape are valid over a broad range of conditions.
An enhanced particle inerter device (EPID) is innovatively developed to mitigate the dynamic responses of multi-story structures subjected to seismic excitations. The device dissipates energy through ...tuning, particle-cavity collisions, and the inertia amplification effect of the inerter. Multi-story response can be mitigated when the inerter unit connect the particle device and the cross-story. In this paper, a shaking table test was conducted to investigate the working mechanism of the EPID on the dynamic response of multi-story structures. A series of parametric studies were undertaken to analyze both the individual and combined effects of the particle damping unit and inerter unit within the device. Furthermore, a parameter optimization analysis guided by a genetic algorithm was carried out, resulting in a significant enhancement of 27.92% in displacement control and 24.41% in acceleration control when compared to the traditional design. Moreover, the energy dissipated by the main structure with the optimized EPID shows a decrease of 45.4% when compared to the traditional design.
•An enhanced particle inerter device is proposed with experiments and simulations.•EPID’s multi-story vibration control effect is studied through shaking table test.•Individual and combined effects of particle unit and inerter unit are studied.•An EPID parameter optimization analysis based on genetic algorithm is proposed.
•PSO and particle damping model are combined to guide the design of particle damping.•Take a plate as an example to check the particle damper layout optimization.•The method is to guide the ...application of particle damping on engineering structures.
Particle damping technology is widely used to suppress the structure vibration in different fields. It is thus important to develop an optimization method of the particle damper design to achieve good damping effect. Here, a theoretical model of particle damping based on multiphase flow theory of gas-particle is used to predicate the acceleration response of asymmetrical particle-damping plate through COMSOL-MATLAB co-simulation. On the basis of the accuracy of acceleration response prediction (i.e. simulation results vs. experimental results), particle swarm algorithm is introduced to optimize the parameters of particle dampers within different frequency ranges. The optimal results (i.e. acceleration response curves and total values of acceleration) are compared with the non-optimal results, showing its feasibility of particle-damping asymmetrical plate in various target frequency ranges. Comparing to the non-optimal case, the damping effect after optimization improves significantly by reducing 10 dB more within the frequency ranges.
•A multiparameter variable TPD is designed for vibration control of a manipulator.•The TPD achieves vibration suppression of a large mass with a small control mass.•The vibration reduction effects of ...the TPD outperform those of DVAs and PDs.•A comparison analysis of TPD and DVA explores the working acceleration threshold.•The TPD can adaptively adjust to achieve optimal vibration absorption.
A novel lightweight variable-stiffness tuned particle damper (TPD) is designed to efficiently control low-frequency vibrations across a wide frequency range in manipulators, combining particle damping technology with dynamic vibration absorber principles. This study aims to integrate both theoretical and experimental approaches to comprehensively investigate the TPD's variable stiffness, damping characteristics, and vibration attenuation efficacy. Methodologically, the research entails designing and analyzing the TPD's variable stiffness mechanism, establishing a coupled dynamic model between the TPD and the manipulator, fabricating a prototype TPD, and subsequently evaluating its frequency variability range and vibration control effectiveness. Additionally, the study explores the semi-active control capabilities of the TPD. Results demonstrate that the designed TPD, utilizing a single 100 g particle, achieves a substantial 60 % reduction in manipulator amplitudes within the 5–10 Hz frequency range. Moreover, the study identifies the TPD's operational acceleration threshold to be 0.6 g, thereby broadening its applicability across various scenarios. Furthermore, the integration of semi-active control algorithms augments the absorption frequency band. These findings highlight that the TPD offers multi-parameter adjustability in stiffness, damping, and mass, with a lighter mass compared to traditional dynamic vibration absorbers. It can effectively mitigate vibrations without altering the original system's dynamic characteristics, presenting a promising solution for engineering applications necessitating versatile and efficient vibration control mechanisms.
•The proposed metamaterials greatly improved dual characteristics of static stiffness and vibration suppression comparing with the initial configuration.•The incorporation of metal pins enhanced the ...load-bearing capacity by improving the local stiffness of the unit cell.•The metal pins generated the low frequency resonant modes and improved the bandgap property by improving the absorption efficiency of resonant energy.•Comparing Please check funding information and confirm its correctness.with the metal pins, the structure of particle damping can remain the high stiffness, and conveniently adjust the frequency of the resonant bandgaps and further dissipate the vibration energy.
In this paper, an improved re-entrant metamaterial based on 3D printing was proposed, which exhibits enhanced stiffness and vibration suppression ability compared to the original metamaterial. The proposed metamaterial allows for intentional adjustment of the bandgap by incorporating metal pins of varying sizes or weight into the ring structures. Furthermore, the addition of particle damping inside the rings enhances the design flexibility of the bandgap, enabling customization of the middle and low frequency ranges. Experimental and simulation comparisons are conducted to evaluate the static properties and vibration suppression ability of the metamaterial. The results demonstrate a 172.4 % increase in load-bearing capacity and a significant improvement in vibration suppression of the proposed metamaterial relative to the original configuration. The vibration suppression of the proposed metamaterial can be further enhanced by introducing particle damping into the metal tube, and the vibration suppression frequency can be intentionally adjusted by changing the dosage of particle damping. This research presents a novel approach for the design and optimization of metamaterials.
This survey provides an overview of the different approaches seen in the literature concerning particle damping. The emphasis is on particle dampers used on beams vibrating at frequencies between ...10 Hz and 1 kHz. Design examples, analytical formulations, numerical models, and experimental setups for such dampers are gathered. Modeling approaches are presented both for particle interaction and for systems equipped with particle dampers. The consequences of the nonlinear behavior of particle dampers are brought to attention. As such, the apparent contradictions of the conclusions and approaches presented in the literature are highlighted. A list of particle simulation software and their use in the literature is provided. Most importantly, a suggested approach to create a sound numerical simulation of a particle damper and the accompanying experimental tests is given. It consists of setting up a discrete element method simulation, calibrating it with literature data and a representative damper experiment, and testing it outside of the range of operation used for the tuning.
Particle impact dampers: Past, present, and future Lu, Zheng; Wang, Zixin; Masri, Sami F. ...
Structural control and health monitoring,
January 2018, 2018-01-00, 20180101, Letnik:
25, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Particle damping, an effective passive vibration control technology, is developing dramatically at the present stage, especially in the aerospace and machinery fields. The aim of this paper is to ...provide an overview of particle damping technology, beginning with its basic concept, developmental history, and research status all over the world. Furthermore, various interpretations of the underlying damping mechanism are introduced and discussed in detail. The theoretical analysis and numerical simulation, together with their pros and cons are systematically expounded, in which a discrete element method of simulating a multi‐degree‐of‐freedom structure with a particle damper system is illustrated. Moreover, on the basis of previous studies, a simplified method to analyze the complicated nonlinear particle damping is proposed, in which all particles are modeled as a single mass, thereby simplifying its use by practicing engineers. In order to broaden the applicability of particle dampers, it is necessary to implement the coupled algorithm of finite element method and discrete element method. In addition, the characteristics of experimental studies on particle damping are also summarized. Finally, the application of particle damping technology in the aerospace field, machinery field, lifeline engineering, and civil engineering is reviewed at length. As a new trend in structural vibration control, the application of particle damping in civil engineering is just at the beginning. The advantages and potential applications are demonstrated, whereas the difficulties and deficiencies in the present studies are also discussed. The paper concludes by suggesting future developments involving semi‐active approaches that can enhance the effectiveness of particle dampers when used in conjunction with structures subjected to nonstationary excitation, such as earthquakes and similar nonstationary random excitations.
•A new floating slab track vibration isolator is developed using particle damping vibration absorption and bandgap vibration resistance.•Using the low-frequency vibration reduction effect of ...non-obstructive particle damping (NOPD), the attenuation of resonance peaks in the begin of bandgap frequency range is realized.•A coupled train-floating slab track-bridge dynamic model is established to investigate the vibration isolation capability.
The environmental vibrations caused by rail transit continue to increase in importance. Even though there are a variety of efficient vibration reduction measures, there is still room for further improvement by trying new, effective vibration control mechanisms. In this paper, a new floating slab track vibration isolator is developed using particle damping vibration absorption and bandgap vibration resistance. Using the low-frequency vibration reduction effect of non-obstructive particle damping (NOPD), the particulate material is added to the outer ring vibrator to participate in vibrations, and the attenuation of resonance peaks in the begin of bandgap frequency range is realized. The energy loss factor and damping ratio of particle damping for different particle sizes are analyzed using a discrete element model. A finite element model with integrated particle damping effect is also formulated and the bandgap behavior of phononic crystal vibration isolator (PCVI) with additional particle damping is analyzed. The effect of particle damping is assessed by calculating the force transmission spectrum.
In order to the investigate vibration isolation performance of the combined NOPD-PCVI when subjected to excitation from trains running at different speeds, a coupled train-floating slab track-bridge dynamic model is established. The results show that the NOPD-PCVI offers better vibration isolation than a steel-spring vibration isolator and the traditional PCVI (T-PCVI) in the frequency band of 50–150 Hz. The energy dissipation provided by particle damping and the bandgap damping of phononic crystals reduce the vertical accelerations of the bridge deck in the bandgap frequency band. Specifically, the total vertical accelerations of the bridge deck equipped with NOPD-PCVIs is reduced by 15.3 dB compared to steel springs, and 5.6 dB compared to T-PCVIs, respectively.
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