Vibration Mitigation Using Passive Active Tunable (PAT) System: Experimental Aspects

2006 ◽  
Vol 129 (2) ◽  
pp. 209-216
Author(s):  
N. Sarigul-Klijn ◽  
I. Lopez ◽  
M. Sarigul-Klijn ◽  
D. Karnopp

The objective of this paper is to test and model a single-degree-of-freedom vibration isolation system with a magnetorheological (MR) foam damper under harmonic and random excitations. The results of this research are valuable for understanding the characteristics of the MR foam damper and include the experimental design and results of vibration mitigations for frequency ranges up to 2000Hz. Transmissibility and acceleration hysteresis experiments of the MR foam damper system with different levels of input current are discussed. A simple damper design that eliminates many of the constraints normally associated with fluid filled devices is presented. Constitutive equations of the Bouc–Wen model are used to validate and characterize the MR foam damper. The motion characteristics of the MR foam damper are studied. Experimental results reveal that the mechanical behavior of the MR foam damper is nonlinear and that the field-dependent behavior of MR foam damper is associated with the applied frequency and acceleration amplitude. Experiments demonstrate MR foam damper works well in controlling vibrations and can be controlled and tuned for specific applications.

Author(s):  
Md. Emdadul Hoque ◽  
Takeshi Mizuno ◽  
Yuji Ishino ◽  
Masaya Takasaki

A vibration isolation system is presented in this paper which is developed by the combination of multiple vibration isolation modules. Each module is fabricated by connecting a positive stiffness suspension in series with a negative stiffness suspension. Each vibration isolation module can be considered as a self-sufficient single-degree-of-freedom vibration isolation system. 3-DOF vibration isolation system can be developed by combining three modules. As the number of motions to be controlled and the number of actuators are equal, there is no redundancy in actuators in such vibration isolation systems. Experimental results are presented to verify the proposed concept of the development of MDOF vibration isolation system using vibration isolation modules.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
X. Gao ◽  
Q. Chen

A methodology is presented to study the resonance and stability for a single-degree-of-freedom (SDOF) system with a piecewise linear-nonlinear stiffness term (i.e., one piece is linear and the other is weakly nonlinear). Firstly, the exact response of the linear governing equation is obtained, and a modified perturbation method is applied to finding the approximate solution of the weakly nonlinear equation. Then, the primary and 1/2 subharmonic resonances are obtained by imposing continuity conditions and periodicity conditions. Furthermore, Jacobian matrix is derived to investigate the stability of resonance responses. Finally, the results of theoretical study are compared with numerical results, and a good agreement is observed.


2021 ◽  
pp. 107754632110005
Author(s):  
Yonglei Zhang ◽  
Guo Wei ◽  
Hao Wen ◽  
Dongping Jin ◽  
Haiyan Hu

The vibration isolation system using a pair of oblique springs or a spring-rod mechanism as a negative stiffness mechanism exhibits a high-static low-dynamic stiffness characteristic and a nonlinear jump phenomenon when the system damping is light and the excitation amplitude is large. It is possible to remove the jump via adjusting the end trajectories of the above springs or rods. To realize this idea, the article presents a vibration isolation system with a cam–roller–spring–rod mechanism and gives the detailed numerical and experimental studies on the effects of the above mechanism on the vibration isolation performance. The comparative studies demonstrate that the vibration isolation system proposed works well and outperforms some other vibration isolation systems.


2016 ◽  
Vol 87 (1) ◽  
pp. 633-646 ◽  
Author(s):  
Xinlong Wang ◽  
Jiaxi Zhou ◽  
Daolin Xu ◽  
Huajiang Ouyang ◽  
Yong Duan

2012 ◽  
Vol 30 (6) ◽  
pp. 063201 ◽  
Author(s):  
Katsuya Iwaya ◽  
Ryota Shimizu ◽  
Akira Teramura ◽  
Seiji Sasaki ◽  
Toru Itagaki ◽  
...  

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