Passive Vibration Control Research Articles

On energy dissipation or harvesting of tuned viscous mass dampers for SDOF structures under seismic excitations

In the past decade, tuned viscous mass dampers (TVMD) have been demonstrated as effective seismic resistant dampers. However, theoretical study on energy dissipation or energy harvesting of the TVMD has rarely been investigated, particularly, whether or not its optimal passive vibration control and energy dissipation maximization are consistent remains questionable. Here, from the theoretical perspective, we present an analysis of energy dissipation or energy harvesting of the TVMD in terms of damping power or output power, respectively. We derive the closed-form solutions of the average damping power of a single-degree-of-freedom (SDOF) structure-TVMD system under white-noise base excitations or seismic excitations modeled by the Kanai-Tajimi spectra, which is verified against the Monte Carlo simulations. Based on the closed-form solutions, the influences of the TVMD parameters, site conditions, and structural dynamic characteristics on the average damping power are analyzed via a parametric study. Theoretical results indicate that structural damping, site condition, structural period, frequency ratio, and inertance-to-mass ratio have a significant impact on the damping power or dissipated energy. In addition, the TVMD dissipates much more energy at a soft-soil site than at a stiff-soil site. At a stiff-soil site, the TVMD dissipates more energy for a short-period structure than for a long-period structure, however, at a soft-soil site, the law is the opposite. The study also presents the theoretical upper bound of the output power of an energy-harvesting TVMD. Particularly, results also illustrate that the maximization of TVMD energy dissipation is not consistent with the optimal passive vibration control. This study may shed light on the TVMD studies for seismic response control or energy harvesting purposes in the years to come.

Vibration control of an optical arm

Several nonlinear treatments of piezoelectric voltages have been studied and developed. These techniques greatly improve the switching capabilities of piezoelectric materials. There are active and passive vibration control techniques: Passive technology involves connecting piezoelectric elements to a passive grid; and active technology requires a bulky system that contains at least a sensor, a controller, and a feedback actuator. In addition, control units and actuators require external power supplies and amplifiers. In addition, control units and actuators require external power supplies and amplifiers. SSD (Synchronous Switch Damping) technology allows optimal management of energy transfer in multiphysical couplings, especially electromechanical couplings created by piezoelectric elements. Based on nonlinear manipulation of the voltage of active elements embedded in the host structure, they greatly increase the extracted mechanical energy, which is then converted into electrical energy. Two main areas can benefit from this optimization: vibration control (SSD) technology, because more energy is extracted from the structure to minimize its energy vibration, and energy harvesting (SSH) technology, because the harvested electrical energy becomes sufficient to supply low consumption electronic circuits. This work focuses on vibration control and energy harvesting using embedded piezoelectric elements. First, the SSD principle applied to piezoelectric materials is introduced. Then, a summary is presented of the work consisting on estimating the attenuation obtained on the vibrations of an optical arm by non-linear SSD techniques.

Passive Vibration Control of Floating Offshore Wind Turbine Based on Mechatronic Inerter

Passive Vibration Control of Floating Offshore Wind Turbine Based on Mechatronic Inerter

A Review Paper on Comparative Analysis on RCC Structure with Energy Dissipation Device and Composite Structure

Abstract: In recent years considerable attention has been paid to research and development of structural vibration control devices with particular emphasis on mitigation of wind and seismic response of buildings. Many vibration-control measures like passive, active, semi-active and hybrid vibration control methods have been developed. Base isolation is a passive vibration control system. The isolator partially reflects and partially absorbs input seismic energy before it gets transmitted to the superstructure. Lead rubber bearing isolators are placed between the superstructure and foundation, which reduces the horizontal stiffness of the system. It thereby increases the time period of the structure and decreases the spectral acceleration of the structure. The superstructure acts like a rigid body, thus inter storey drift is reduced. This study is concerned with the effects of various vertical irregularities on the seismic response of a structure and controls this response using base isolation. The objective of the study is to carry out response spectrum analysis. The predominant lateral loads acting upon building structures are earthquake and wind induced forces. If wind load is much greaterthan earthquake load, the lateral force resisting system required to tackle wind loading may be enough to resist the smaller earthquake load. In this situation, a seismic base isolator will not bring any benefit to the building system. Furthermore, if time period of a building without isolator is greater, incorporation of isolator will not bring much difference to the building behavior with respect to seismic load. Additionally, for buildings with lowerstructural time periods, incorporation of an isolator will greatly alter the seismic behavior

Seismic Performance of Coupled Buildings Connected by Yield and SMA Dampers

Efficient attenuation and control of structural vibration during a seismic event is a critical factor for overall safety and serviceability of the adjacent buildings with little clearance between them. Without proper vibration control measures, adjacent buildings may undergo severe pounding and collapse leading to damage of life and property during an earthquake. Use of energy dissipation devices to connect adjacent buildings has been a popular method of vibration control and to stop mutual poundings. Among various available energy dissipation devices, Shape Memory Alloy (SMA) based dampers are getting popularity in recent time. Various studies are performed to show the efficiency of SMAs as passive vibration control device, but a holistic study of SMA dampers for non-linear connected buildings is still missing. Thus, here a comparative study on the efficiency of metallic yield and super-elastic SMA dampers as passive vibration control device is provided, for non-linear connect buildings. In the present study, non-linear dynamic time history analyses are performed to determine the response (peak floor acceleration and displacement, and floor residual displacement). Time history analyses confirm better acceleration and displacement (both peak and residual) control efficiency of SMA dampers over yield dampers. Finally, superiority of the SMA damper over the yield damper is established via parametric study under varying damper, building and ground motion parameters. Over yield damper, SMA damper reduces acceleration by 13 % to 56 %, displacement by 2 % to 47 %, and residual displacement by 15 % to 64 %.

Enhancement of the vibration attenuation characteristics in local resonance metamaterial beams: Theory and experiment

Enhancing vibration isolation with local resonance metamaterials has attracted widespread attention due to the low-frequency band gap. However, the narrow band gaps limit its application. To improve vibration suppression properties over a wide frequency range under the constraints of space and mass in engineering, this paper presents the modeling techniques and design strategies for a local resonance elastic metamaterial beam with multiple resonators. The local resonance sub-system contains multi-degree-of-freedom resonators and is periodically mounted on the elastic beam. Two special cases, the elastic metamaterial beam with one-degree-of-freedom local resonator sub-system (1-DOF) and two-degree-of-freedom local resonator sub-system (2-DOF) are used to investigate the vibration attenuation characteristics in detail. Results are presented in the form of attenuation constant, which are calculated by the extended plane wave expansion (EPWE) method. The effects of frequency spacing, damping and mass ratio on the vibration attenuation characteristics of elastic metamaterial beams are comprehensively investigated. The results show that a wider and more stable attenuation range can be obtained by reasonably adjusting these three parameters. Finally, the comparison of experimental and simulation results demonstrates that the design strategies proposed in this paper can broaden the vibration attenuation regions. The theoretical approaches and design schemes can provide effective guidance for passive vibration control.

Realisation of acoustic black holes using multi-material additive manufacturing

Acoustic black holes (ABHs) have been widely accepted as an effective passive vibration control technique, with multiple configurations investigated for different applications. However, traditional manufacturing techniques may limit the potential geometries and configurations of the ABH. For example, the required damping layer has to be applied to the surface of the ABH taper rather than being embedded throughout or within the taper. In addition, conventional subtractive manufacturing is particularly wasteful for the realisation of ABHs, which rely on the removal of material to create a tapering structure. Therefore, in this work, we investigate the use of multi-material additive manufacturing as a potential solution, which avoids waste material in the manufacturing process and is capable of realising complex geometries, such as enclosing one material inside another. An ABH taper in a beam termination application has been implemented using polymer multi-material inkjet printing. The additively manufactured ABH was modelled using finite element analysis, before being manufactured and experimentally tested to enable an investigation of the vibration attenuation capabilities of such an ABH realisation.

Dynamics of a harmonically excited nonlinear pipe conveying fluid equipped with a local nonlinear energy sink

When the magnitude of the lateral elastic deformation of a pipe over its length is more prominent than in a linear situation, it is necessary to use nonlinear terms to reduce the gap between the mathematical model and the real system. Also, the importance of nonlinear terms is more considerable when a pipe conveying fluid is studied. Since the passive vibration control of pipes is of great significance, one may employ a nonlinear energy sink (NES) as the control configuration attached to the pipe. Hence, in this study, the dynamics of a harmonically excited nonlinear pipe conveying fluid attached to a local NES is investigated. The boundary conditions are assumed doubly clamped. The two nonlinear partial differential equations of motion are derived. Using the method of Galerkin, considering four shape modes, five nonlinear coupled equations are obtained for describing the pipe and NES’s models. The most applicable outcome of this research is preventing the chaotic motion, when the pipe is equipped by the NES at one-fourth of one of its ends. Chaotic regions might take whole different forms for a linear pipe conveying fluid.

Vibration control systems in a building prototype: Application of SMA coil springs in diagonal bracing and TMD

The growing concern with the efficiency and reliability of civil structures that are slim, flexible and highly vulnerable to earthquakes, side winds and impacts can be addressed with the use of smart materials. Among the available techniques, passive control stands out due to its low cost, low maintenance, and no need for an external energy source. In this sense, this work proposes the incorporation of NiTi superelastic SMA springs in a diagonal bracing arrangement and as a secondary device in a Tuned Mass Damper (TMD) to improve the passive vibration control of a 3-DOF building prototype. The study compares the efficiency of the proposed control systems through the modal analysis of the structure under scenarios combining different control types (diagonal bracing or TMD), vibration types (impulse excited or base-forced) and passive attenuation (with or without SMA springs). It was concluded that the length of the SMA spring attenuators has a direct influence on the control capacity, with the shorter springs providing a higher attenuation efficiency, as they generate greater mechanical hysteresis and dissipate more mechanical energy, while adding less mass to the structure. In terms of the amplitudes reached in the experimental modal analysis, the TMD with the SMA springs as a secondary device was the most efficient technique, allowing reductions of up to 74% in impulse excitation and 44% in forced vibration. In terms of added mass, TMD also proved to be more effective, reducing about 63% of NiTi SMA material in impulse excitation and 73% in forced vibration, when compared to diagonal bracing.

Field test study on the evaluation of the microvibration controlling capacity of a mass concrete layer

Microvibration induced by natural disturbance and human activities has an adverse effect on the operation of the large-scale and ultraprecise facilities in the world. Under such circumstances, a passive vibration control method is generally deployed for such vibration-sensitive facilities, taking the High Energy Photo Source (HEPS) in Beijing as an example, a 3 m-thick mass concrete layer forming a ring foundation was cast at the facility, where a 1 m-thick reinforced concrete slab (RC slab) lies. Since microvibration control plays a crucial role in the operation of such large-scale scientific and ultraprecise facilities and few studies have been reported for large-scale concrete layer as antimicrovibration devices, this paper presents four field tests in Beijing, China, to evaluate the vibration control capacity of a mass concrete layer. Based on a large number of field tests, the effect of applying the concrete layer is discussed, and a reference is provided for the construction of similar facilities. The vibration signals, generated by shock excitation and ambient excitation, are measured through a highly sensitive and high-accuracy vibration acquisition system. It is concluded that the existence of the 1 m-thick RC slab has little influence on the microvibration signal frequency distribution in the vertical direction and that the signals from the concrete layer and subsoil differ by approximately 10 Hz in the vertical direction while differing by approximately 5 Hz in the horizontal direction. The microvibration control ability of the concrete layer is favorable in a higher frequency band over 20 ~ 30 Hz and more than 50% attenuation can be gained through the concrete layer; however, the microvibration control ability is not significant below 20 ~ 30 Hz. The vibration levels across different heights of the concrete layer section are the same. To prevent adverse vibration disturbance below 20 ~ 30 Hz, it is suggested that the traffic and road surface conditions should be taken into consideration when choosing the construction location. In addition, a long-term monitoring shows that 75% vibration energy at the site is firmly related to the construction activities which are approximately 1.4 km from the site.

Fatigue Damage Mitigation for Welded Beam-to-Column Connections in Steel High-Rise Buildings Using Passive Vibration Control

To investigate the use of vibration control systems in fatigue damage mitigation for welded beam-to-column connections in steel high-rise buildings, cases of both a single connection under constant amplitude cyclic loading and multi-connections in a high-rise building under the stochastic wind, with and without the fluid viscous damper (VFD) and the tuned mass damper (TMD), are discussed respectively. The finite element analysis and the fatigue assessment are conducted so that the mitigation effect, the effect of technical parameters and the conditions of both high-cycle fatigue and low-cycle fatigue are all discussed. The results show that the VFD and the TMD systems are both effective in the mitigation of local fatigue damage along with the structural displacement for both cases. The VFD generally has a better mitigation effect than the TMD and it starts to take effect instantly with the external loading, but it causes a phase difference in structural responses, while the situation of the TMD is quite the opposite. The displacement and the local stress show similar and synchronous mitigation trends so that the damping systems can be designed based on either of them. The VFD should be designed with a smaller damping exponent and a larger damping coefficient in a braced installation form, while the TMD can be designed using the optimal parameters. The optimized VFD layout plan is that VFDs are placed between the two connections with large relative displacement and relative velocity on higher floors and these two connections with VFDs should be near to the targeted connection. The negative fatigue damage mitigation mainly stems from insufficient lateral support force so that the direct installation of VFDs may result in a negative fatigue damage mitigation effect in the connections with limited lateral support.

Lyapunov-Based Stability Analysis for Fluid Conveying System With Parallel Nonlinear Energy Sinks

In order to reduce the possibility of structural fatigue and increase the lifetime of conveying fluid pipe, transverse vibration must be effectively eliminated. In this work, using parallel nonlinear energy sinks (NESs), a passive vibration controller is proposed to dissipate the vibration energy of the conveying fluid pipe. A high-order model of the conveying fluid pipe-parallel NESs system, in the form of partial differential equation, is derived and then converted into a quadratic form model containing the gradient information of a convex function. Combining the energy disturbance technique and first order convexity characteristic, the exponential stability of the closed-loop system is proved, which addresses the effectiveness of the proposed parallel NESs. Then, numerical simulations are given to verify the theoretical results and to illustrate the advantages of parallel NESs comparing with single NES. Finally, the reliability of the proposed approach is preliminarily verified through experiment.

Assistant investigation of energy dissipation in non-obstructive particle damper based on a neural network using simulated annealing backpropagation

The particle damper has been widely used as an efficient passive vibration control device in recent years. The highly non-linear characteristic of the energy dissipation mechanism is essential for our increased understanding of non-obstructive particle damper (NOPD). To connect motion modes of the granular system and energy dissipation, we developed a neural network using simulated annealing backpropagation (SA-BP) to predict the loss factor of NOPD in this paper. The simulations based on the verified discrete element method (DEM) model are carried out, and the data is used to train and test the neural network. Based on the prediction of a well-trained neural network using SA-BP, the relationship between the loss factors and the rheology behaviors of the granular system is discussed. This paper effectively combines intelligent algorithms (SA-BP) and particle damping characteristics. The algorithm is expected to be further used as an auxiliary method for the experimental study of the granular system.

Experimental exploration of unpowered propellers for vortex-induced vibration suppression of flexible riser

Passive control of the vortex-induced vibrations (VIVs) of flexible risers has been typically studied to alleviate their VIV responses by means of breaking the spanwise correlation, modifying the structural characteristic, or disturbing the flow field. However, this paper proposed using innovative suppression devices—unpowered propellers—to mitigate VIVs and output energy through passive rotation under flowing fluids. The effectiveness of three-, four-, and six-blade propellers for VIV suppression was experimentally examined in the Reynolds number range of 2600–10,400. Seven identical propellers were installed uniformly along a riser facing the incoming flow for VIV suppression. The response parameters of the riser models, including the displacement, frequency, trajectory, and fatigue damage, were investigated. Moreover, a comprehensive evaluation of the unpowered propellers, determined by the suppression efficiency and the cost, was also conducted. The experimental results showed that all three types of propellers significantly decreased the VIV amplitudes and inhibited high-order frequency components. Increasing the number of blades effectively enhanced the amplitude suppression of the propellers, whereas it had almost no effect on the vibration frequencies of the controlled risers. It is worth noting that the three-blade propellers with the best comprehensive evaluation may not be a reasonable choice in high-velocity water.

Damping performance of particle dampers with different granular materials and their mixtures

A particle damper is a passive vibration control technology that utilizes the high damping properties of granular materials for reducing the vibration amplitude of a structure over a wide frequency range. Energy dissipation of particle damper is a highly nonlinear and complex physical phenomenon [1]. Previous studies have shown that the damping mechanism of a particle damper depends on several factors, like particle size and shape, granular material, filling ratio, and the number of particles [2–5]. Out of these parameters, the type of granular material used in the particle damper plays a major role in reducing the vibration amplitude of a mechanical structure. Therefore, the current contribution aims to investigate the influence of 20 different granular materials on vibration attenuation. The granular materials under investigation are subdivided into two major groups, namely: soft particles, like rubber granulate, and hard particles, like steel balls. Furthermore, this paper proposes a hybrid particle damper in which two different types of granular material mixtures are used, i.e. a particle damper in which for instance soft particles are mixed with hard particles. Moreover, in this contribution, fine particles, like rubber powder are mixed with hard granular materials like lead shot, which can be seen as an extension of the fine particle impact damper concept [6]. The humidity-dependent behavior of particle dampers is also another important issue, which is addressed in this paper. To investigate the vibration attenuation efficiency of all the granular materials and their mixtures including the humidity-dependent behavior, a laser scanning vibrometer device is used. Generally, the relationship between the vibration response and the granular material mass is rarely addressed in the literature, which can restrict the industrial application of particle dampers. Hence, the additional mass of the granular material is also a focus of this paper. The experimental investigation shows that the vibration response of the test specimen is significantly lower for particles with lower densities in the low-frequency range. Furthermore, an excellent damping efficiency can be also observed for the particle damper with a granular material mixture. The results obtained in this study are not restricted to any special structure and can be implemented in several industrial applications, where vibration and noise attenuation plays a major role, like automotive, aerospace, wind turbine, medical technology, mining, etc.

Characteristics of passive vibration control for exponential non-viscous damping system: Vibration isolator and absorber

Materials or structures made of polymers or composites often exhibit non-viscous damping behavior. The non-viscous damping forces that depend on the history velocity can be expressed by the exponential non-viscous damping model. Some polymer or composite materials can be used as damping materials for kinetic energy absorption in the dynamic systems. Vibration isolator and absorber are usually considered for shock absorption. In this study, transfer ratios of vibration isolator and absorber with exponential non-viscous damping system are derived by using the Laplace transform. The dimensionless amplitude of vibration absorber with exponential non-viscous damping is derived too. Compared to viscous damping system, transfer ratio and dimensionless amplitude of exponential non-viscous damping system are influenced by the ratio of the relaxation parameter and natural frequency or the frequency of the external load. With the non-viscous damping material used in vibration control, the ratio is therefore a non-negligible factor which should be considered in analysis.

Exact augmented perpetual manifolds as a tool for the determination of similar rigid body modes: Corollary for determining backbone curves of autonomous systems

Perpetual points in mathematics have been defined recently, and their significance in describing the dynamics of systems is ongoing research. In mechanical engineering, the perpetual points of linear unforced mechanical systems are associated with rigid body motions, and they form the perpetual manifolds. The systems that admit perpetual manifolds of rigid body motions are called perpetual mechanical systems. The concept of perpetual manifolds has been extended to the exact augmented perpetual manifolds, whereas all the accelerations are equal but not necessarily zero. A theorem defines the conditions of external forces that lead to rigid body motion of externally forced mechanical systems. Herein, based on this theorem, a corollary is proven that, through a very simple framework, defines specifications to mechanical systems resulting in the existence of rigid body similar modes and can serve as a tool in the nonlinear normal modes (NNMs) theory for the determination of their backbone curves of dissipative mechanical systems. Further, on these, backbone curves can be used for passive vibration control design of N-degree-of-freedom (dof) mechanical systems. The verification of the theory has been done with the design of a 5-dof nonlinear perpetual mechanical system with three types of boundaries, linear, nonlinear smooth, and nonsmooth boundaries. The numerical simulations results are in excellent agreement with the theory. Although 5-dof mechanical systems have been examined, the corollary is valid for N-degree-of freedom systems. The corollary provides a simplified framework for the design of mechanical systems to admit rigid body modes for systems with a general configuration that is not obvious using traditional techniques. This work is rather significant in mechanical engineering because it provides a new tool firstly for determining similar NNMs of dissipative mechanical systems and secondly for the design of passive vibration control devices.

Modeling and optimization of multiple tuned mass dampers for a barge-type floating offshore wind turbine

Significant structural responses pose potential hazards to the safe operation of floating offshore wind turbines (FOWTs). To effectively mitigate the motion of FOWTs using conventional passive vibration control methods such as tuned mass damper (TMD) and multiple tuned mass damper (MTMD), an optimization method for TMD and MTMD in a barge-type FOWT is proposed in this study. A simplified dynamic model of a barge FOWT with MTMD, which includes the tower first bending and floating platform degrees of freedom (DOFs), in addition to the simplified DOF of the MTMD, is derived. The corresponding fully coupled numerical model is established using the updated simulation tool FAST-SC. Subsequently, the unknown parameters and accuracy of the simplified dynamic model are validated via comparison with the results of the coupled numerical model. Moreover, an optimization method is proposed based on the simplified dynamic model considering the prominent coupling effects of FOWT and computational expense, and the GA algorithm is used for TMD and MTMD optimization. Furthermore, the effectiveness of the optimized TMDs and MTMD is evaluated based on the reduction in the coupled responses of the barge FOWT under the selected environmental conditions. Compared with the optimized TMD in the nacelle, the optimized TMD in the platform and MTMD are proven to be more feasible for vibration mitigation under complex environmental loads. Moreover, an improved steady output is obtained using the optimized vibration control methods, in addition to the excellent mitigation effects on structural responses.

Analytical approach to suppress the vibration of spur gear pair using particle damping technique

Vibration and noise have annihilated effect on the mechanical systems. These two are main adverse parameters leading to many undesirable effects lead to fatigue and failure of the machine decreased reliability, energy losses and degraded performance. Vibration damping is reactive vibration control method. Passive and active damping techniques are used to reduce the resonant vibrations. Theory of energy dissipation mechanism is followed by particle damping and is one of the passive vibration control technology. Particle damping, an impact mass is attached contains number of particles. The dissipation of loss of vibrational energy will occur due to impact, friction and change of energy. Damping is an effect of reducing, preventing its oscillations. Particle impact dampers are used to decrease the undesirable vibration in automobile industries, robots aerospace industries, gear box, etc. like engineering applications. This paper focused on the particle damping technology to reduce the vibrations generated in transmission spur gear. The model is developed which have cavity or holes in which particle dampers are present; it decide the relation between friction coefficient of the particles at constant rotational speed, various particle size. In present research damping particle of different sizes are selected to study the effect on damping using modal analysis. We found that, at the low or minimum speed, small and edgeless particles have good damping impact and at fast speed, more unpleasant and irregular particles are even better. It is observed that, the particle size and damping effect are directly proportional. This reduces the noise and harshness in system and ultimately improves the quality performance and life of the gearbox.

Implementation of Active and Passive Vibration Control of Flexible Smart Composite Manipulators with Genetic Algorithm

Implementation of Active and Passive Vibration Control of Flexible Smart Composite Manipulators with Genetic Algorithm