Parametric Uncertainty and Random Excitation in Energy Harvesting Dynamic Vibration Absorber

2020 ◽  
Author(s):  
M Rajarathinam ◽  
Shaikh Faruque Ali
Keyword(s):  
Energy Harvesting ◽  
Damping Ratio ◽  
Parametric Uncertainty ◽  
Electrical Energy ◽  
Harmonic Excitation ◽  
Random Excitation ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Host Structure

Abstract An energy harvesting dynamic vibration absorber is studied to suppress undesirable vibrations in a host structure as well as to harvest electrical energy from vibrations using piezoelectric transduction. The present work studies the feasibility of using vibration absorber for harvesting energy under random excitation and in presence of parametric uncertainties. A two degrees of freedom model is considered in the analytical formulation for the host along with the absorber. A separate equation is used for energy generation from piezoelectric material. Two studies are reported here, (i) with random excitation where the base input is considered to be Gaussian; (ii) parametric uncertainty is considered with harmonic excitation. Under random base excitation the analytical results show that, with the proper selection of parameters, harvested electrical energy can be increased along with the reduction in vibration of the host structure. Graphs are reported showing trade-off between harvested energy and vibration control. Whereas, Monte Carlo simulations are carried out to analyze the system with parametric uncertainty. This showed that the mean harvested power decreases with an increase in uncertainties in the natural frequency as well as damping ratio. In addition, optimal electrical parameters for obtaining maximum power for the case of uncertain parameters are also reported in this study.

scholarly journals Optimal parameters of dynamic vibration absorber for linear damped rotary systems subjected to harmonic excitation

2020 ◽  
Author(s):  
Vu Duc Phuc ◽  
Tong Van Canh ◽  
Pham Van Lieu
Keyword(s):  
Vibration Suppression ◽  
Fixed Point Theory ◽  
Damping Ratio ◽  
Harmonic Excitation ◽  
Tuning Parameter ◽  
Vibration Absorber ◽  
Optimal Parameters ◽  
Dynamic Vibration Absorber ◽  
Practical Applications ◽  
Dynamic Vibration

Dynamic vibration absorber (DVA) is a simple and effective device for vibration absorption used in many practical applications. Determination of suitable parameters for DVA is of significant importance to achieve high vibration reduction effectiveness. This paper presents a   method to find the optimal parameters of a DVA attached to a linear damped rotary system excited by harmonic torque. To this end, a closed-form formula for the optimum tuning parameter is derived using the fixed-point theory based on an assumption that the damped rotary systems are lightly or moderately damped. The optimal damping ratio of DVA is found by solving a set of non-linear equations established by the Chebyshev's min-max criterion. The performance of the proposed optimal DVA is compared with that obtained by existing optimal solution in literature. It is shown that the proposed optimal parameters are possible to obtain superior vibration suppression compared to existing optimal formula. Extended simulations are carried out to examine the performance of the optimally designed DVA and the sensitivity of the optimum parameters. The simulation results show that the improvement of the vibration performance on damped rotary system can be as much as 90% by using DVA.

Energy Harvesting Dynamic Vibration Absorbers

2013 ◽  
Vol 80 (4) ◽  
Author(s):  
Shaikh Faruque Ali ◽  
Sondipon Adhikari
Keyword(s):  
Energy Harvesting ◽  
Vibration Suppression ◽  
Fixed Point Theory ◽  
Electrical Circuit ◽  
Closed Form Expression ◽  
Vibration Absorber ◽  
Original Structure ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Host Structure

Energy harvesting is a promise to harvest unwanted vibrations from a host structure. Similarly, a dynamic vibration absorber is proved to be a very simple and effective vibration suppression device, with many practical implementations in civil and mechanical engineering. This paper analyzes the prospect of using a vibration absorber for possible energy harvesting. To achieve this goal, a vibration absorber is supplemented with a piezoelectric stack for both vibration confinement and energy harvesting. It is assumed that the original structure is sensitive to vibrations and that the absorber is the element where the vibration energy is confined, which in turn is harvested by means of a piezoelectric stack. The primary goal is to control the vibration of the host structure and the secondary goal is to harvest energy out of the dynamic vibration absorber at the same time. Approximate fixed-point theory is used to find a closed form expression for optimal frequency ratio of the vibration absorber. The changes in the optimal parameters of the vibration absorber due to the addition of the energy harvesting electrical circuit are derived. It is shown that with a proper choice of harvester parameters a broadband energy harvesting can be obtained combined with vibration reduction in the primary structure.

Dynamic Vibration Absorber Design to Suppress Boring Chatter: Absorber Parameters Identification Based on Modal Correlation

2013 ◽  
Vol 753-755 ◽  
pp. 1816-1820 ◽  
Author(s):  
Zhen Kun Hu ◽  
Ming Wang ◽  
Tao Zan
Keyword(s):  
Damping Ratio ◽  
Correlation Method ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Element Analysis ◽  
Simple Method ◽  
Dynamic Vibration ◽  
The Finite Element Analysis ◽  
Chatter Control ◽  
Modal Method

The dynamic vibration absorber (DVA) is generally used to suppress the machining vibration in boring processes. The DVA consists of an additional massspringdamper sub-system, and needs accurately tuning of its natural frequency and damping ratio to match the main structure for vibration control. For obtaining the optimal performance of the DVA, the parameters of the DVA used in a boring bar is identified using modal correlation method, which combines the finite element analysis method with test modal method to validate the FEMs results. The analysis results show that the modal correlation method is an effective and simple method to accurately identify the dynamic parameters of DVA and guarantee the optimal design of the DVA for boring chatter control.

Optimal Design of an Inerter-Based Dynamic Vibration Absorber Connected to Ground

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Shaoyi Zhou ◽  
Claire Jean-Mistral ◽  
Simon Chesne
Keyword(s):  
Fixed Point ◽  
Optimal Design ◽  
Transient Response ◽  
Damping Ratio ◽  
Vibration Absorber ◽  
Practical Implementation ◽  
Primary System ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
The Stability

Abstract This paper addresses the optimal design of a novel nontraditional inerter-based dynamic vibration absorber (NTIDVA) installed on an undamped primary system of single degree-of-freedom under harmonic and transient excitations. Our NTIDVA is based on the traditional dynamic vibration absorber (TDVA) with the damper replaced by a grounded inerter-based mechanical network. Closed-form expressions of optimal parameters of NTIDVA are derived according to an extended version of fixed point theory developed in the literature and the stability maximization criterion. The transient response of the primary system is optimized when the coupled system becomes defective, namely having three pairs of coalesced conjugate poles, the proof of which is also spelt out in this paper. Moreover, the analogous relationship between NTIDVA and electromagnetic dynamic vibration absorber is highlighted, facilitating the practical implementation of the proposed absorber. Finally, numerical studies suggest that compared with TDVA, NTIDVA can decrease the peak vibration amplitude of the primary system and enlarge the frequency bandwidth of vibration suppression when optimized by the extended fixed point technique, while the stability maximization criterion shows an improved transient response in terms of larger modal damping ratio and accelerated attenuation rate.

Parameters optimization of dynamic vibration absorber based on grounded stiffness, inerter, and amplifying mechanism

2021 ◽  
pp. 107754632110382
Author(s):  
Peng Sui ◽  
Yongjun Shen ◽  
Shaopu Yang ◽  
Junfeng Wang
Keyword(s):  
Analytical Solution ◽  
Vibration Isolation ◽  
Damping Ratio ◽  
Vibration Absorber ◽  
Primary System ◽  
Vibration Absorbers ◽  
Stiffness Ratio ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Dynamic Vibration Absorbers

In the field of dynamics and control, some typical vibration devices, including grounded stiffness, inerter and amplifying mechanism, have good vibration isolation and reduction effects, especially in dynamic vibration absorber (DVA). However, most of the current research studies only focus on the performance of a single device on the system, and those DVAs are gradually becoming difficult to meet the growth of performance demand for vibration control. On the basis of Voigt dynamic vibration absorber, a novel dynamic vibration absorber model based on the combined structure of grounded stiffness, inerter, and amplifying mechanism is presented, and the analytical solution of the optimal design formula is derived. First, the motion differential equation of the system is established, and the normalized amplitude amplification factor of the displacement is calculated. It is found that the system has three fixed points unrelated to the damping ratio. The optimal frequency ratio is obtained based on the fixed-point theory. In order to ensure the stability of the system, it is found that inappropriate inerter coefficient will cause the system instable when screening optimal grounded stiffness ratio. Accordingly, the best working range of inerter is determined. Finally, optimal grounded stiffness ratio and approximate optimal damping ratio are also obtained. The influence of inerter coefficient and magnification ratio on the response of the primary system is analyzed. The correctness of the derived analytical solution is verified by numerical simulation. Compared with other dynamic vibration absorbers, it is verified that presented model has superior vibration absorption performance and provides a theoretical basis for the design of a new type of dynamic vibration absorbers.

Reduction of vertical abnormal vibration in carbodies of low-floor railway trains by using a dynamic vibration absorber

2017 ◽  
Vol 232 (5) ◽  
pp. 1437-1447 ◽  
Author(s):  
Qunsheng Wang ◽  
Jing Zeng ◽  
Lai Wei ◽  
Cheng Zhou ◽  
Bin Zhu
Keyword(s):  
Simulation Model ◽  
Field Test ◽  
Damping Ratio ◽  
Dynamic Performance ◽  
Vertical Vibration ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Pitching Motion ◽  
Suspension Parameters ◽  
Dynamic Vibration

A field test on the dynamic performance of a 100% low-floor railway train with five cars was conducted, and a vertical vibration at around 8 Hz was mainly studied for the background of the research. The vibration around 8 Hz, defined as the abnormal vertical vibration, was proved to be due to the pitching motion of the carbodies, which significantly affected the dynamic performance of the vehicle with a maximum increase of 0.309 in the vertical Sperling index. The dynamic vibration absorber theory was applied to reduce the abnormal vibration of carbodies to around 8 Hz by building a vertical mathematic model and a three-dimensional dynamical simulation model. The results of the theoretical analysis show that the stiffness of the articulated device between carbodies is the reason for the pitching motions at around 8 Hz, and the stiffness significantly affects the main frequency of the vertical vibration of carbodies. What’s more, the application of dynamic vibration absorber theory on low-floor railway trains can reduce the vertical abnormal vibration effectively. Yet, reasonable suspension parameters are needed; otherwise, the vibration of carbodies, including the mass ratio, the suspension frequency, the damping ratio, and the suspended location would be aggravated. Optimal suspension parameters of the dynamic vibration absorber system were used in the simulation model, and the result shows a good agreement with the numerical results; the attached dynamic vibration absorber system on carbodies significantly reduces the vibration of carbodies at around 8 Hz. However, it should be noted that the dynamic vibration absorber is only effective at high-speed stage (beyond 40 km/h) where the pitching motion of carbodies is obvious; this conclusion is consistent with the results of the field test.

scholarly journals Vibration Control of Time-Varying Delay under Complex Excitation

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1081
Author(s):  
Kaiwei Wu ◽  
Chuanbo Ren ◽  
Yuanchang Chen ◽  
Sujuan Shao ◽  
Jilei Zhou ◽  
...  
Keyword(s):  
Time Delay ◽  
Harmonic Excitation ◽  
Vibration Absorber ◽  
Time Interval ◽  
Control Effect ◽  
Dynamic Vibration Absorber ◽  
Time Varying Delay ◽  
Dynamic Vibration ◽  
Vibration Attenuation ◽  
Varying Delay

The existing available research outcomes on vibration attenuation control for time-delay feedback indicate that, for the delay dynamic vibration absorber with fixed time-delay control parameters, under harmonic excitation, a good vibration attenuation control effect occurs on the vibration of the main system. However, the effect is not obvious for complex excitation. Aiming at the above problems, in a short time interval, a harmonic excitation with the same displacement size as the complex excitation was established. Then, by calculating its equivalent amplitude and equivalent frequency, a harmonic equivalent method for complex excitation was proposed in this paper. The time-delay parameters were adjusted according to the equivalent frequency of harmonic equivalent excitation in real time; therefore, a good vibration attenuation control effect was obtained through the delay dynamic vibration absorber in the discrete time interval. In this paper, research on a time-varying delay dynamic vibration absorber was conducted by taking the two-degree-of-freedom vibration system with a delay dynamic vibration absorber as an example. The simulation results show that the proposed control method can reduce the vibration of the main system by about 30% compared with the passive vibration absorber. This can obviously improve the performance of the time-delay dynamic vibration absorber. It provides a new technical idea for the design of vehicle active frame system.

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