Nonlinear damping and mass effects of electromagnetic shunt damping for enhanced nonlinear vibration isolation

2021 ◽  
Vol 146 ◽  
pp. 107010 ◽  
Author(s):  
Hongye Ma ◽  
Bo Yan
2022 ◽  
pp. 107754632110514
Author(s):  
Sivakumar Solaiachari ◽  
Jayakumar Lakshmipathy

In this study, a new type of vibration isolator based on fluidic actuators and a composite slab was tested experimentally with an unbalanced disturbance. Quasi-zero stiffness vibration isolation techniques are advanced and provide effective isolation performance for non-nominal loads. The isolation performance of the proposed isolator was compared to that of a nonlinear vibration isolator equipped with fluidic actuators and a mechanical coil spring (NLVIFA). The NLVIFA system is better suited to non-nominal loads; however, the mechanical spring axial deflection leads to limited amplitude reduction in the system. To address this issue, a cross buckled slab was developed to replace a mechanical coil spring for absorbing vertical deflection by transverse bending, which is made of a specially developed composite material of Basalt fiber reinforced with epoxy resin and enhanced with graphene nano pellets. This current study was concerned with the theoretical analysis and experimental investigations of the proposed nonlinear vibration isolator with fluidic actuators and composite material (NLVIFA-CM), which performs under quasi-zero stiffness characteristics. Because of its reduced axial deflection, the theoretical and experimental results show that the NLVIFA-CM system outperforms the NLVIFA system and other linear type vibration isolators in terms of isolation performance. Furthermore, the proposed vibration isolator makes a significant contribution to low-frequency vibration.


2012 ◽  
Vol 152-154 ◽  
pp. 1077-1081 ◽  
Author(s):  
Zhao Qi He ◽  
Yu Chao Song ◽  
Hong Liang Yu

A nonlinear spring-mass model is established to study the dynamic characteristics of nonlinear vibration isolator. By use of ADAMS software, the influence of stiffness, foundation displacement excitation and frequency of external excitation on the nonlinear vibration isolation systems are analyzed. Results indicate that the linear vibration system needs 4s to achieve stability, but the nonlinear vibration system only needs 0.1s. The response value increases with the increase of excitation frequency, the response pick value increases by 61.58% and 102.35% and each corresponding stable value increases by 159.35% and 309.87%.


2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Lahcen Mokni ◽  
Mohamed Belhaq

Previous numerical and experimental works show that time delay technique is efficient to reduce transmissibility of vibration in a single pneumatic chamber by controlling the pressure in the chamber. The present work develops an analytical study to demonstrate the effectiveness of such a technique in reducing transmitted vibrations. A quarter-car model is considered and delayed hysteretic suspension is introduced in the system. Analytical predictions based on perturbation analysis show that a delayed hysteretic suspension enhances vibration isolation comparing to the case where the nonlinear damping is delay-independent.


2015 ◽  
Vol 138 (2) ◽  
Author(s):  
J. C. Carranza ◽  
M. J. Brennan ◽  
B. Tang

In this paper, the behavior of a single degree-of-freedom (SDOF) passive vibration isolation system with geometrically nonlinear damping is investigated, and its displacement and force transmissibilities are compared with that of a linear system. The nonlinear system is composed of a linear spring and a linear viscous damper which are connected to a mass so that the damper is perpendicular to the spring. The system is excited by a harmonic force applied to the mass or a displacement of the base in the direction of the spring. The transmissibilities of the nonlinear isolation system are calculated using analytical expressions for small amplitudes of excitation and by using numerical simulations for high amplitude of excitation. When excited with a harmonic force, the forces transmitted through the spring and the damper are analyzed separately by decomposing the forces in terms of their harmonics. This enables the effects of these elements to be studied and to determine how they contribute individually to the nonlinear behavior of the system as a whole. For single frequency excitation, it is shown that the nonlinear damper causes distortion of the velocity of the suspended mass by generating higher harmonic components, and this combines with the time-varying nature of the damping in the system to severely distort the force transmitted though the damper. The distortion of the force transmitted through the spring is much smaller than that through the damper.


2013 ◽  
Vol 419 ◽  
pp. 223-227 ◽  
Author(s):  
Rui Huo ◽  
Hui Yu ◽  
Yan Feng Guan

In view of its prototype in engineering application, a theoretical model of multi-supported nonlinear vibration isolation system installed on flexible foundation is studied, including derivation of system dynamic equations and analysis of system dynamic characteristics. For effectiveness evaluation of nonlinear vibration isolation systems, a generalized time-averaged power is proposed as an extension of classical theory of vibratory power flow, and a numerical solution method of time-averaged power is probed accompanying with the numerical solution of nonlinear dynamic equations. In a further concrete calculation example, an air spring vibration isolation system of a small UAV engine is numerically simulated based on Runge-Kutta method, and dynamic behavior and power flow transmission characteristics influenced by system parameters are investigated.


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