Abstract:

An acoustic metamaterial consisting of a homogeneous damped plate with parallel attached resonators is presented in this report. Theoretical analysis shows that multiple resonant-type band gaps are obtained, in which the lower bound frequency of each band gap coincides with the resonance frequencies of the resonators; Compared with the metamaterial plate with resonators attached in series reported by Peng and Pai (2015), parallel arrangement of the resonators causes a larger width and smaller lower bound of the second band gap while the first band gap keeps almost the same, which makes an easier combination of the multiple band gaps into a wider one It is noted that damping has significant influence on the band gaps and the effective mass density. Specifically, damping can broaden the band gaps with the sacrifice of the deactivating the band gap effect, smooth and lower the frequency responses for the whole ranges. Comparatively, damping from the host plate can smooth and reduce the responses in low-frequency range (lower than the first band gap), while damping of the resonators can move the unbounded effective mass density region to a lower frequency and shrinks the negative-density ranges by means of damping out part of energy. Finite element simulation reveals that the metamaterial plateworks on the mechanism of multiple conventional vibration absorbers generating inertia forces to counteract the bending forces induced by the flexural waves and stretching the plate within the band gaps. Practical implementation of the metamaterial plate with two different configurations is also discussed to show the potential applications for engineering.
 
About the Speaker

秦庆华（Qing-Hua Qin）教授，于1984年和1990年获华中科技大学固体力学专业硕士和博士学位，1994年获DAAD—王宽诚基金赴德国Stuttgart大学访问研究。1995年-1997年到清华大学作博士后研究；1997和2002年分获澳大利亚研究理事会Queen Elizabeth II 研究员和Professorial Fellow位置，2004年至今在澳大利亚国立大学33678新甫京国际品牌担任教授、副院长 (2011-2013)、研究中心材料加工制造组的带头人等职位。2000年被聘为华中科技大学客座教授；2002年被天津大学聘为特聘教授。在应用力学领域，已发表300多篇期刊论文，出版7部专著，获得澳大利亚科学院颁发的J G. Russell奖。

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