薄膜超材料的等效特性分析及试验研究

发布时间：2018-03-28 05:29

本文选题：薄膜超材料　切入点：谐振单元　出处：《振动与冲击》2017年18期

【摘要】：基于一维超材料梁的理论思想,将薄膜超材料简化成具有周期性的谐振单元和一维梁的结构;根据薄板的Kirchhoff理论,建立了整体结构的运动方程,计算了周期性谐振单元作用力及薄膜两侧载荷的声压差。利用牛顿第二定律及虚功原理,得到了薄板不同阶的振动模态幅值A_n所满足的运动方程。通过引入等效密度概念,得到等效密度共振形式受薄膜的刚度k、厚度h、谐振单元周期常数L及附加质量M等因素影响,并针对每种影响因素进行了等效密度峰值的分析;得出在一定尺寸范围内,得到了薄膜厚度h越薄,谐振单元刚度与质量的比值越小,共振频率越低的结论;而且周期常数L越大,薄膜自身的共振形式与谐振单元的共振形式同时存在,且薄膜本身的振动形式越强烈。通过探讨谐振单元质量与透射峰值的试验验证,表明质量-弹簧谐振子的共振作用对薄膜超材料的透射吸收起到至关重要作用。
[Abstract]:Based on the theory of one-dimensional supermaterial beam, the thin film supermaterial is simplified into a periodic resonant element and a one-dimensional beam structure. According to the Kirchhoff theory of thin plate, the motion equation of the whole structure is established. By using Newton's second law and the principle of virtual work, the equations of motion satisfied by the vibration mode amplitude an of different order of thin plate are obtained. By introducing the concept of equivalent density, the concept of equivalent density is introduced. The equivalent density resonance form is affected by the factors such as the film stiffness k, thickness h, resonant cell cycle constant L and additional mass M, and the peak value of equivalent density is analyzed for each factor. It is concluded that the thinner the film thickness h, the smaller the ratio of the stiffness to mass of the resonant element and the lower the resonance frequency, and the larger the periodic constant L is, the more the resonant form of the film itself exists simultaneously with the resonance form of the resonant element. The stronger the vibrational form of the thin film is, the more important the resonance action of mass-spring harmonic oscillator is to the transmission absorption of the thin film supermaterial through the experimental verification of the mass and the transmission peak value of the resonant element.
【作者单位】：军械工程学院车辆与电气工程系;
【基金】：武器装备“十二五”预先研究项目
【分类号】：TB383.2

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