Active-Adaptive Vibration Absorbers and its Vibration Attenuation Performance

Chen

Yang

et al. 2014

Smart Mater. Struct.

In the past, adaptive tuned vibration absorbers (ATVAs) based on magnetorheological elastomers (MREs) have mainly been developed in a shear working mode. The enhancing effect of MREs in squeeze mode has already been investigated, but ATVAs in squeeze mode have rarely been studied. This paper reports the development of a compact squeeze MRE absorber and its subsequent performance in various magnetic fields characterized under various frequencies by a vibration testing system. The results revealed that the natural frequency of the MRE absorber working in squeeze mode can be tuned from 37 Hz to 67 Hz. Following this, a theoretical model based on magnetic dipole theory was developed to investigate the dynamic performance of the squeeze MRE absorber, and the vibration attenuation of the squeeze MRE absorber was then verified by mounting it on a beam with supports under both ends. The results revealed that the squeeze MRE absorber extended its vibration attenuation range from 37 Hz to 67 Hz while the passive absorber was only effective around 53 Hz.

Section: Ginder and Coworkers Did Pioneering Work On The Development mentioning

confidence: 99%

The development of an adaptive tuned magnetorheological elastomer absorber working in squeeze mode

Chen

Yang

et al. 2014

Smart Mater. Struct.

“…Deng developed an MRE absorber working in shear mode, whose natural frequency can vary from 55 to 82 Hz (Deng et al, 2006; Deng and Gong, 2008). Subsequently, Gong’s group applied a voice motor on an MRE absorber in order to counteract the effect of damping and increase the absorber’s effectiveness (Liao et al, 2011; Peng and Gong, 2013). As a way to further improve and complete the MRE-based absorber, Sun et al developed a multilayered MRE absorber which is much better at dealing with vibrations with larger amplitude (Sun et al, 2015a, 2015c).…”

Section: Introductionmentioning

confidence: 99%

Development of a nonlinear adaptive absorber based on magnetorheological elastomer

Journal of Intelligent Material Systems and Structures

Yang

Yildirim

et al. 2017

The resonance shift property of magnetorheological elastomer is important for developing adaptive absorbers. However, it is well-known that passive nonlinear absorbers have wider effective frequency bandwidths. This article combines these two characteristics in order to develop a hybrid magnetorheological elastomer absorber which can shift its natural frequency and has a wider absorption bandwidth under each constant current. The adaptability and nonlinearity were fully verified experimentally. Afterwards, the absorption ability of the hybrid magnetorheological elastomer absorber was investigated and analyzed. The results show that the effective bandwidth of this absorber is broadened under certain levels of current than linear absorber, and this is caused by the presence of nonlinearity; and the adaptability induced by the magnetorheological elastomer undoubtedly empowers the absorber possible to trace the excitation frequency changing in real time. A short-time Fourier transform was finally used to control the magnetorheological elastomer absorber to verify its controllability, showing that an optimal absorption transmissibility was achieved by the controlled hybrid absorber.

“…Due to the working principle of an absorber, the performance of vibration suppression is significantly associated with the bandwidth of the device's own natural frequency. The traditional passive absorber only works efficiently in a very narrow bandwidth; in order to overcome issues associated with narrow bandwidth, variable stiffness magnetorheological elastomers (MREs) can be incorporated into an absorbers design [6,7]. Magnetorheological elastomers, are a smart field-responsive material, that can increase their elastic modulus or stiffness monotonically under as an applied external magnetic field increases [8][9][10], and then immediately revert to their initial properties as the magnetic field is removed.…”

Section: Introductionmentioning

confidence: 99%

Design and verification of a hybrid nonlinear MRE vibration absorber for controllable broadband performance

Yildirim

et al. 2017

Smart Mater. Struct.

In this work, a hybrid nonlinear magnetorheological elastomer (MRE) vibration absorber has been designed, theoretically investigated and experimentally verified. The proposed nonlinear MRE absorber has the dual advantages of a nonlinear force-displacement relationship and variable stiffness technology; the purpose for coupling these two technologies is to achieve a large broadband vibration absorber with controllable capability. To achieve a nonlinear stiffness in the device, two pairs of magnets move at a rotary angle against each other, and the theoretical nonlinear force-displacement relationship has been theoretically calculated. For the experimental investigation, the effects of base excitation, variable currents applied to the device (i.e. variable stiffness of the MRE) and semi-active control have been conducted to determine the enhanced broadband performance of the designed device. It was observed the device was able to change resonance frequency with the applied current; moreover, the hybrid nonlinear MRE absorber displayed a softening-type nonlinear response with clear discontinuous bifurcations observed. Furthermore, the performance of the device under a semi-active control algorithm displayed the optimal performance in attenuating the vibration from a primary system to the absorber over a large frequency bandwidth from 4 to 12 Hz. By coupling nonlinear stiffness attributes with variable stiffness MRE technology, the performance of a vibration absorber is substantially improved.