Passage Through Resonance in a Three Degree-of-Freedom Vibration Isolation System

Author(s):  
Ryo Kawana ◽  
Tetsuro Tokoyoda ◽  
Kazushige Sato ◽  
Masatsugu Yoshizawa ◽  
Toshihiko Sugiura

This paper deals with transient nonlinear vibration of a rigid body suspended on a foundation by elastic springs and constrained in a plane. In such a three degree-of-freedom vibration isolation system, we assume that ‘2-1-1’ internal resonance exists between the vertical and horizontal vibrations of the rigid body and the rotational vibration about its center of gravity. Next, the vibration of the rigid body is captured into or passes through resonance when the rotation speed of an unbalanced rotor equipped with the rigid body is increased. We theoretically examined the transient behavior of passage through resonance under the condition that a DC motor directly drives the unbalanced rotor with a limited electric current. Moreover, the experiment was conducted with a physical model of such a system, and transient oscillations through resonance were observed and compared with theoretical results in a few cases of limited currents.

Author(s):  
Tomohiko Tange ◽  
Ryo Kawana ◽  
Tetsuro Tokoyoda ◽  
Masatsugu Yoshizawa ◽  
Toshihiko Sugiura

This paper deals with transient nonlinear vibration of a rigid body suspended on a foundation by elastic springs and constrained in a plane. In such a three degree-of-freedom vibration isolation system, we assume that ‘2-1-1’ internal resonance exists between the vertical and horizontal vibrations of the rigid body and the rotational vibration about its center of gravity. Our main purpose is to examine theoretically the transient behavior passing through resonance under the condition that the D.C. motor directly drives the unbalanced rotor. Numerical simulation was carried out to clarify effects of rate of increasing V(t) on the peak amplitude of the vibration of the rigid body and on the driving torque of the D.C. motor. Moreover, experiment was conducted with a physical model of a three degree-of-freedom vibration isolation system, and the transient behavior passing through resonance was observed and compared with theoretical results in a typical case with internal resonance.


2013 ◽  
Vol 21 (8) ◽  
pp. 1608-1621 ◽  
Author(s):  
Chunsheng Song ◽  
Zude Zhou ◽  
Shengquan Xie ◽  
Yefa Hu ◽  
Jinguang Zhang ◽  
...  

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.


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