A multi-modal adaptive tuned mass damper based on shape memory alloys

2019 ◽  
Vol 30 (4) ◽  
pp. 536-555 ◽  
Author(s):  
Marta Berardengo ◽  
Giovanni EP Della Porta ◽  
Stefano Manzoni ◽  
Marcello Vanali

This article deals with the design of an innovative adaptive multi-modal tuned mass damper able to change its eigenfrequencies to recover shifts of the natural frequencies of the primary system which needs to be damped. This is accomplished using systems of shape memory alloy wires connected to a number of masses equal to the number of modes to be damped. This article presents the analytical model used to describe the behaviour of the adaptive tuned mass damper, showing which parameters can affect the performances of the device. The layout proposed for the tuned mass damper proves to be able to act on a wide frequency range and to work adaptively on at least two eigenfrequencies at the same time with a given level of independence. The last goal is accomplished, thanks to the special features of the shape memory alloys, by heating (or cooling) each wire of the device independently and allowing the exploitation of two different effects: the change of the axial load in the wires and the change of the geometry of the device. The reliability of both the design approach and the model of the new device is proved by means of an experimental campaign performed considering a random disturbance.

Author(s):  
Marcelio Ronnie Dantas de Sá ◽  
Armando Wilmans Nunes da Fonseca Júnior ◽  
Yuri Moraes ◽  
Antonio Almeida Silva

2005 ◽  
Vol 128 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Lei Zuo ◽  
Samir A. Nayfeh

Whenever a tuned-mass damper is attached to a primary system, motion of the absorber body in more than one degree of freedom (DOF) relative to the primary system can be used to attenuate vibration of the primary system. In this paper, we propose that more than one mode of vibration of an absorber body relative to a primary system be tuned to suppress single-mode vibration of a primary system. We cast the problem of optimization of the multi-degree-of-freedom connection between the absorber body and primary structure as a decentralized control problem and develop optimization algorithms based on the H2 and H-infinity norms to minimize the response to random and harmonic excitations, respectively. We find that a two-DOF absorber can attain better performance than the optimal SDOF absorber, even for the case where the rotary inertia of the absorber tends to zero. With properly chosen connection locations, the two-DOF absorber achieves better vibration suppression than two separate absorbers of optimized mass distribution. A two-DOF absorber with a negative damper in one of its two connections to the primary system yields significantly better performance than absorbers with only positive dampers.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Liberty Deberg ◽  
Masood Taheri Andani ◽  
Milad Hosseinipour ◽  
Mohammad Elahinia

Shape memory alloys (SMAs) provide compact and effective actuation for a variety of mechanical systems. In this work, the distinguished superelastic behavior of these materials is utilized to develop a passive ankle foot orthosis to address the drop foot disability. Design, modeling, and experimental evaluation of an SMA orthosis employed in an ankle foot orthosis (AFO) are presented in this paper. To evaluate the improvements achieved with this new device, a prototype is fabricated and motion analysis is performed on a drop foot patient. Results are presented to demonstrate the performance of the proposed orthosis.


2006 ◽  
Vol 06 (04) ◽  
pp. 541-557 ◽  
Author(s):  
CHUNXIANG LI

The dual-layer multiple tuned mass dampers (DL-MTMD) with a uniform distribution of natural frequencies are proposed, which consist of one large tuned mass damper (L-TMD) and an arbitrary number of small tuned mass dampers (S-TMD). The structure is represented by a generalized system corresponding to the specific vibration mode to be controlled. The criterion for assessing the optimum parameters and effectiveness of the DL-MTMD is based on the minimization of the minimum values of the maximum dynamic magnification factors (DMF) of the structure installed with the DL-MTMD. Also considered is the stroke of the DL-MTMD. The proposed DL-MTMD system is demonstrated to show higher effectiveness and robustness to the change in frequency tuning, in comparison to the multiple tuned mass dampers (MTMD) with equal total mass ratios. It is also demonstrated to be more effective than the dual tuned mass dampers (DTMD) with one large and one small tuned mass damper, but they maintain the same level of robustness to the change in frequency tuning. The DL-MTMD system can be easily manufactured as the optimum value for the linking dashpots between the structure and L-TMD is shown to be zero.


2013 ◽  
Vol 22 (9) ◽  
pp. 095016 ◽  
Author(s):  
Sudib K Mishra ◽  
Sourav Gur ◽  
Subrata Chakraborty

2003 ◽  
Vol 25 (2) ◽  
pp. 65-76
Author(s):  
Nguyen Dong Anh ◽  
Nguyen Chi Sang

Among the fundamental concepts for structure control, passive control systems have a significant role since they do not require additional energies produced by actuator. The basic of passive control is to incorporate a secondary system into the primary structure in order to transfer a part of the vibration energy of the primary system into the secondary one. In the paper the design of an optimal tuned mass damper (TMD) for a structure subjected to second order coloured noise excitation is investigated in order to minimize the sum of response mean squares of components of the primary system with a given ranking priority.


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