Page 257 - 《振动工程学报》2026年第5期
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第 39 卷第 5 期                       振 动 工 程 学 报                                       Vol. 39 No. 5
               2026 年  5 月                     Journal of Vibration Engineering                       May 2026



                                       双   稳    态   周   期   结   构    带   隙   调   制



                                                刘恩彩, 张 瑞, 曾文波

                                         (长沙学院电子信息与电气工程学院,湖南 长沙 410022)


              摘要:双稳态结构因其独特的非线性特性,在低频隔振和能量俘获等领域展现出巨大的应用潜力。本文聚焦由双稳态屈曲梁
              构成的周期结构,通过施加静态预压缩,实现一种无需重新设计结构的带隙调谐机制。建立了该双稳态周期结构的等效离散
              模型,并通过准静态压缩试验标定了模型的关键非线性参数。基于能量景貌理论,揭示了施加静态预压缩量能够有效调制系
              统等效刚度的内在机理。通过理论解析、数值仿真和振动试验,研究了预压缩量对一维双稳态周期结构带隙特性的影响规
              律。研究结果表明:通过增大屈曲梁的预压缩量,可以连续、单调地降低系统的等效刚度,从而使带隙的起始频率向低频区偏
              移。当系统趋近于临界“零刚度”状态时,带隙可被调谐至接近                     0 Hz。振动试验验证了该调谐策略的有效性,结果显示,在小
              强度与大强度激励下,带隙起始频率分别实现了                 52 和  56 Hz 的迁移。本研究可为设计具有低频、宽带、可调隔振特性的力学
              超材料提供依据。

              关键词: 非线性动力学;双稳态结构;带隙调谐;能量景貌
              中图分类号:O322        文献标志码:A        DOI:10.16385/j.cnki.issn.1004-4523.202507073


                                     Bandgap tuning in bistable periodic structures


                                              LIU Encai,ZHANG Rui,ZENG Wenbo
                      (Department of Electronic Information and Electrical Engineering,Changsha University,Changsha 410022,China)

              Abstract: The  fixed  operational  frequency  ranges  of  conventional  mechanical  metamaterials  severely  limit  their  adaptability  in  complex
              environments.  Bistable  structures, leveraging  their  inherent  nonlinear  properties, provide  a  promising  foundation  for  developing  tunable
              systems.  This  paper  presents  a  robust  mechanism  for  tuning  the  bandgap  of  a  periodic  structure  composed  of  bistable  buckled  beams.
              The proposed strategy,based on applying static pre-compression,offers a passive yet highly effective alternative to methods requiring active
              materials  or  complete  structural  redesign.  The  investigation  integrates  theoretical  modeling, numerical  simulation, and  experimental
              validation. The complex continuum mechanics of the one-dimensional periodic structure were abstracted into an equivalent discrete spring-
              mass-damper  model.  Its  key  nonlinear  parameters —the  negative  linear  stiffness  and  positive  cubic  stiffness  coefficients —were  precisely
              calibrated  via  quasi-static  compression  experiments  on  a  unit  cell  fabricated  using  additive  manufacturing  with  thermoplastic  polyurethane
              (TPU). The energy landscape theory was employed to elucidate the intrinsic tuning mechanism. The results reveal that static pre-compression
              asymmetrically alters the characteristic ‘W’-shaped potential energy profile,thereby modifying the curvature at the equilibrium position. This
              modulation of the potential well’s geometry enables continuous control over the system’s local equivalent stiffness and can induce a topological
              transition from a bistable to a monostable state. The findings reveal a strong correlation between the applied pre-compression and the bandgap
              location.  Increasing  the  pre-compression  on  the  buckled  beams  results  in  a  continuous  and  monotonic  decrease  in  the  system’s  equivalent
              stiffness. Consequently,the bandgap’s starting frequency shifts towards the lower frequency region,with theoretical predictions indicating a
              tunable range from 207 Hz down to near-zero frequencies. As the system approaches a critical “zero-stiffness” state—where a potential well
              coalesces  with  the  energy  barrier —the  potential  for  ultra-low  frequency  isolation  is  unlocked.  The  efficacy  of  this  tuning  strategy  was
              experimentally validated using an 8-cell prototype,demonstrating significant shifts in the bandgap starting frequency of 54% and 64% under
              small  and  large  intensity  excitations, respectively.  The  system  exhibited  characteristic  softening  nonlinearity, evidenced  by  a  further
              downward shift of the bandgap at higher excitation amplitudes. This research establishes a robust and accessible methodology for bandgap
              manipulation, providing  a  foundational  reference  for  the  design  of  next-generation  mechanical  metamaterials  with  low-frequency,
              broadband,and tunable vibro-acoustic properties.
              Keywords:nonlinear dynamics;bistable structure;bandgap tuning;energy landscape




                  收稿日期:2025-07-31;修订日期:2025-11-04
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