Reliability analysis of the hysteretic nonlinear energy sink in shock mitigation considering uncertainties

2020 ◽  
Vol 26 (23-24) ◽  
pp. 2261-2273 ◽  
Author(s):  
George C Tsiatas ◽  
Dimitra A Karatzia
Keyword(s):  
Reliability Analysis ◽  
Nonlinear Energy Sink ◽  
System Response ◽  
Primary System ◽  
Dissipation Energy ◽  
Linear Elastic ◽  
Shock Mitigation ◽  
Energy Sink ◽  
Elastic Spring ◽  
Nonlinear Energy

The reliability of the hysteretic nonlinear energy sink in shock mitigation is investigated herein. The hysteretic nonlinear energy sink is a passive vibration control device which is coupled to a primary linear oscillator. Apart from its small mass and a nonlinear elastic spring of the Duffing oscillator, it also comprises a purely hysteretic and a linear elastic spring of potentially negative stiffness. The Bouc–Wen model is used to describe the force produced by both the purely hysteretic and linear elastic springs. The hysteretic nonlinear energy sink protects the primary system through the energy pumping mechanism which transfers energy from the primary system and dissipates it in the hysteretic nonlinear energy sink. Three nonlinear equations of motion describe the resulting two-degree-of-freedom system response. The parameters of the system to be considered as uncertain are the natural frequency of the primary system and the hysteretic nonlinear energy sink linear elastic spring, which follow a normal distribution. A reliability analysis is then performed to evaluate the robustness of the coupled system in the presence of uncertainty. Specifically, the reliability index is calculated based on first passage probabilities of distinct dissipation energy level crossings using the Monte Carlo method. Several examples are examined considering various levels of initial input energy, and useful conclusions are drawn concerning the influence of uncertainty in the system robustness.

Nonlinear Energy Sinks With Nontraditional Kinds of Nonlinear Restoring Forces

2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Mohammad A. AL-Shudeifat
Keyword(s):  
Energy Transfer ◽  
Nonlinear Energy Sink ◽  
Nonlinear Coupling ◽  
Closed Loops ◽  
Strong Resonance ◽  
Shock Mitigation ◽  
Restoring Forces ◽  
Initial Shock ◽  
Energy Sink ◽  
Nonlinear Energy

The nonlinear energy sink (NES) is usually coupled with a linear oscillator (LO) to rapidly transfer and immediately dissipate a significant portion of the initial shock energy induced into the LO. This passive energy transfer and dissipation are usually achieved through strong resonance captures between the NES and the LO responses. Here, a nontraditional set of nonlinear coupling restoring forces is numerically investigated to introduce enhanced versions of the NESs. In this new set of nonlinear coupling restoring forces, one has a varying nonlinear stiffness that includes both of hardening and softening stiffness components during the oscillation, which appear in closed-loops under the effect of the damping. The obtained results by the numerical simulation have shown that employing this kind of the nonlinear restoring forces for passive targeted energy transfer (TET) is promising for shock mitigation.

Optimal Performance Comparison of Nonlinear Energy Sinks and Linear Tuned Mass Dampers

2021 ◽  
Author(s):  
Ivan Yegorov (Egorov) ◽  
Austin Uden ◽  
Daniil Yurchenko
Keyword(s):  
Nonlinear Energy Sink ◽  
Free Vibrations ◽  
Performance Comparison ◽  
Optimal Performance ◽  
Primary System ◽  
Secondary System ◽  
Impulsive Excitation ◽  
Secondary Systems ◽  
Energy Sink ◽  
Nonlinear Energy

Abstract This paper studies a targeted energy transfer (TET) mechanism for a two-degree-of-freedom (TDOF) model in free vibration. The model comprises a primary linear system and a secondary system in the form of an energy sink which can be nonlinear. The free vibrations are considered subject to an impulsive excitation exerted on the primary system, leading to a nonzero initial velocity. The goal is to obtain the spring parameters in the nonlinear energy sink (NES) so as to maximize an energy dissipation measure (EDM) representing the percentage of impulsive energy that is absorbed and dissipated in the NES. A global optimization algorithm is used for this purpose. The optimal performance is assessed for the purely linear, linear-cubic, and purely cubic configurations of the spring connecting the primary and secondary systems. The corresponding results are compared with each other. The optimization process is performed for the EDM averaged over given ranges of the initial impulse and natural frequency in the primary system. It is shown that the type of the optimal configuration can vary depending on these ranges.

Rotary-impact nonlinear energy sink for shock mitigation: analytical and numerical investigations

2019 ◽  
Vol 90 (3) ◽  
pp. 495-521 ◽  
Author(s):  
Adnan S. Saeed ◽  
Mohammad A. AL-Shudeifat ◽  
Alexander F. Vakakis ◽  
Wesley J. Cantwell
Keyword(s):  
Nonlinear Energy Sink ◽  
Numerical Investigations ◽  
Shock Mitigation ◽  
Energy Sink ◽  
Nonlinear Energy

Numerical Investigation of Rotating Nonlinear Energy Sink for Shock Mitigation

2013 ◽  
Author(s):  
Mohammad A. Al-Shudeifat ◽  
Lawrence A. Bergman ◽  
Alexander F. Vakakis
Keyword(s):  
Energy Transfer ◽  
Linear Structure ◽  
Nonlinear Energy Sink ◽  
Initial Energy ◽  
Shock Mitigation ◽  
Nonlinear Targeted Energy Transfer ◽  
Primary Test ◽  
Energy Sink ◽  
Two Degree Of Freedom ◽  
Nonlinear Energy

Passive nonlinear targeted energy transfer (TET) is addressed here by investigating a lightweight rotating nonlinear energy sink (NES). The rotating sink mass has an essentially nonlinear inertial coupling with the two degree-of-freedom linear system (the primary test structure). The proposed rotating NES is numerically investigated where it is found to passively absorb and rapidly dissipate a considerable portion of the initial energy induced by impulse to the linear structure. The parameters of the rotating NES are optimized for the best performance in the vicinity of intermediate and high loads. The fundamental mechanism for significant energy transfer to the NES is its rotational mode; the oscillatory mode of the NES dissipates far less energy. The frequency-energy dependences are investigated through the frequency-energy plot (FEP). Early and strong resonance capture at the lowest modal frequency is observed between the rotator and the structure, at which a significant portion of the induced energy is transferred and dissipated by the rotator. The performance of this device is found to be comparable to existing, stiffness-based NES designs. However, this device is less complicated and more compact.

Dynamics of an Eccentric Rotational Nonlinear Energy Sink

2011 ◽  
Vol 79 (1) ◽  
Author(s):  
O. V. Gendelman ◽  
G. Sigalov ◽  
L. I. Manevitch ◽  
M. Mane ◽  
A. F. Vakakis ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Nonlinear Energy Sink ◽  
Experimental Investigations ◽  
Primary System ◽  
Targeted Energy Transfer ◽  
Energy Sink ◽  
Nonlinear Energy

The paper introduces a novel type of nonlinear energy sink, designed as a simple rotating eccentric mass, which can rotate with any frequency and; therefore, inertially couple and resonate with any mode of the primary system. We report on theoretical and experimental investigations of targeted energy transfer in this system.

Asymmetric Magnet-Based Nonlinear Energy Sink

2014 ◽  
Vol 10 (1) ◽  
Author(s):  
Mohammad A. AL-Shudeifat
Keyword(s):  
Permanent Magnets ◽  
Nonlinear Energy Sink ◽  
Weakly Nonlinear ◽  
Strongly Nonlinear ◽  
Shock Mitigation ◽  
Energy Inputs ◽  
Energy Sink ◽  
Dynamic Structures ◽  
Nonlinear Energy ◽  
Weakly Linear

The nonlinear energy sink (NES) is a light-weighted device used for shock mitigation in dynamic structures through its passive targeted energy transfer (TET) mechanism. Here, a new design for the NES is introduced based on using an asymmetric NES force. This force is strongly nonlinear in one side of the NES equilibrium position, whereas it is either weakly nonlinear or weakly linear in the other side. This is achieved by introducing the asymmetric magnet-based NES in which the asymmetric nonlinear magnetic repulsive force is generated by two pairs of aligned permanent magnets. Consequently, this proposed design is found to provide a considerable enhancement in the shock mitigation performance compared with the symmetric stiffness-based NESs for broadband energy inputs.

Design and performance analysis of a nonlinear energy sink attached to a beam with different support conditions

2015 ◽  
Vol 230 (4) ◽  
pp. 527-542 ◽  
Author(s):  
Majid Kani ◽  
Siamak E Khadem ◽  
Mohammad H Pashaei ◽  
Morteza Dardel
Keyword(s):  
Particle Swarm Optimization ◽  
Performance Analysis ◽  
Nonlinear Energy Sink ◽  
Optimization Method ◽  
Primary System ◽  
Swarm Optimization ◽  
Energy Sink ◽  
Support Conditions ◽  
And Performance ◽  
Nonlinear Energy

In this work, design and performance analysis of a nonlinear energy sink, attached to a beam (the primary system) with different support conditions, will be investigated. Here, the effects of both beam properties and external shock excitation are studied. For this purpose, equations of motion are derived by the Lagrange method. Then, parameters of the nonlinear energy sink are optimized by both sensitivity analysis and particle swarm optimization method. The results show that, increasing the first natural frequency of the primary system, on which an external impulse is imposed, will postpone the nonlinear energy sink activation. Also, increasing the amplitude of the shock excitation will tend to decrease the optimum value of the nonlinear energy sink stiffness. Using the particle swarm optimization method to obtain the optimized parameters of the nonlinear energy sink and its interaction with the primary system, which is a continuous one, is a new research area presented in this work.

An Eccentric Rotator as a Novel Design of a Nonlinear Energy Sink

2011 ◽  
Author(s):  
Oleg V. Gendelman ◽  
Grigori Sigalov ◽  
Mercedes Mane ◽  
Lawrence A. Bergman ◽  
Alexander F. Vakakis ◽  
...  
Keyword(s):  
Numerical Study ◽  
Nonlinear Energy Sink ◽  
Primary System ◽  
Targeted Energy Transfer ◽  
Impulsive Loads ◽  
Chaotic Modes ◽  
Energy Sink ◽  
Novel Design ◽  
Nonlinear Energy ◽  
Good Agreement

We introduce a novel type of the nonlinear energy sink (NES) designed as an eccentric mass rotating within a horizontal plane. The gravity is not a factor here, therefore such a rotator has no eigenfrequency and can inertially couple and resonate with any mode of the primary system. The dynamics of the system consisting of a primary linear oscillator and the eccentric rotator is rich beyond expectations and features multiple resonances and chaotic modes. A numerical study shows that the system, when subject to high impulsive loads, inevitably enters a 1:1 resonance that enables highly efficient targeted energy transfer from the primary mass to the NES. The results of an experimental investigation are in good agreement with the analytical and numerical estimates.

scholarly journals Tuned Nonlinear Energy Sink With Conical Spring: Design Theory and Sensitivity Analysis

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Donghai Qiu ◽  
Sébastien Seguy ◽  
Manuel Paredes
Keyword(s):  
Sensitivity Analysis ◽  
Design Theory ◽  
Linear Part ◽  
Nonlinear Energy Sink ◽  
Design Criterion ◽  
Primary System ◽  
System Specification ◽  
Energy Sink ◽  
Negative Stiffness Mechanism ◽  
Nonlinear Energy

This paper is devoted to the study of a nonlinear energy sink (NES) intended to attenuate vibration induced in a harmonically forced linear oscillator (LO) and working under the principle of targeted energy transfer (TET). The purpose motivated by practical considerations is to establish a design criterion that first ensures that the NES absorber is activated and second provides the optimally tuned nonlinear stiffness for efficient TET under a given primary system specification. Then a novel NES design yielding cubic stiffness without a linear part is exploited. To this end, two conical springs are specially sized to provide the nonlinearity. To eliminate the linear stiffness, the concept of a negative stiffness mechanism is implemented by two cylindrical compression springs. A small-sized NES system is then developed. To validate the concept, a sensitivity analysis is performed with respect to the adjustment differences of the springs and an experiment on the whole system embedded on an electrodynamic shaker is studied. The results show that this type of NES can not only output the expected nonlinear characteristics, but can also be tuned to work robustly over a range of excitation, thus making it practical for the application of passive vibration control.

scholarly journals Integration of Geometrical and Material Nonlinear Energy Sink with Piezoelectric Material Energy Harvester

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Ye-Wei Zhang ◽  
Chuang Wang ◽  
Bin Yuan ◽  
Bo Fang
Keyword(s):  
Vibration Control ◽  
Energy Harvester ◽  
Mechanical Energy ◽  
Piezoelectric Element ◽  
Nonlinear Energy Sink ◽  
Primary System ◽  
Hysteresis Behavior ◽  
Energy Sink ◽  
Material Nonlinear ◽  
Nonlinear Energy

This paper presents a novel design by integrating geometrical and material nonlinear energy sink (NES) with a piezoelectric-based vibration energy harvester under shock excitation, which can realize vibration control and energy harvesting. The nonlinear spring and hysteresis behavior of the NES could reflect geometrical and material nonlinearity, respectively. Two configurations of the piezoelectric device, including the piezoelectric element embedded between the NES mass and the single-degree-of-freedom system or ground, are utilised to examine the energy dissipated by damper and hysteresis behavior of NES and the energy harvested by the piezoelectric element. Similar numerical research methods of Runge-Kutta algorithm are used to investigate the two configurations. The energy transaction measure (ETM) is adopted to examine the instantaneous energy transaction between the primary and the NES-piezoelectricity system. And it demonstrates that the dissipated and harvested energy transaction is transferred from the primary system to the NES-piezoelectricity system and the instantaneous transaction of mechanical energy occupies a major part of the energy of transaction. Both figurations could realize vibration control efficiently.

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