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围绕声振工程研究，本期精选5篇发表在《振动工程学报》上的文章，欢迎阅读！
精选文章·selected articles
谐振放大压电声学超材料梁带隙特性研究。
band gap properties of piezoelectric acoustic metamaterial beams with amplified resonant shunts
【摘要】声学超材料具有亚波长带隙，可应用于结构振动与噪声控制。引入压电材料和谐振分流电路，可以利用电磁振荡和压电材料机电耦合特性在超材料内部形成可调谐局域共振带隙。传统压电声学超材料受到已有压电材料机电耦合系数的限制，带隙一般较窄，无法满足大柔性结构振动与噪声控制中低频宽带需求。因而，该文提出一种谐振放大压电声学超材料梁结构。将压电片划分为传感极和驱动极，传感极输出电压经过运算放大电路放大，然后与谐振电路相连，实现局域共振效果的增强，从而增大带隙宽度。采用有限元方法建立压电声学超材料梁带隙计算模型，分析了带隙位置和宽度随电路放大倍数的变化，研究了等效弹性模量与带隙的关系；利用商用有限元软件**分析了有限周期梁的振动传递特性，验证了带隙计算方法的正确性。研究结果表明，放大电路有效增强了电路的局域共振效果，随着放大倍数的增大，带隙频率降低，带隙宽度增大。
【abstract】acoustic metamaterials h**e sub-w**elength band gaps, which can be applied to noise and vibration control. with the introduction of piezoelectric materials and resonant shunts, tunable locally resonant band gaps can be achieved inside the metamaterial by using electromechanical coupling and electromagnetic oscillation. however, restricted by the limited electromechanical coupling coefficients of **ailable piezoelectric materials, the band width of traditional piezoelectric acoustic metamaterials is generally narrow and unable to satisfy the requirement of low-frequency and broad band gaps in noise and vibration of flexible structures. consequently, this **proposes a type of piezoelectric acoustic metamaterials with amplified resonance. piezoelectric pitches are divided into sensing electrodes and driving electrodes. the output voltage of the sensing electrode is amplified by an operational amplifier circuit and then connected to the resonant circuit to enhance the local resonance effect, thereby increasing the band gap width. the finite element method is adopted to build the model of the band gap calculation of piezoelectric acoustic metamaterial beam. also, the variations of band location and width with amplification factor are analyzed, and the relationship between equivalent elastic modulus and band gaps is studied. a commercial finite element software is employed to analyze the vibration transmission properties of the finite period beam and validate the calculation method of band gaps. the results demonstrate that the local resonance effect can be enhanced by amplification circuits. as the amplification factor increases, the band gap frequency decreases, and the band gap width increases.
高超声速气动热弹性分析降阶研究。
reduced-order modeling research for hypersonic aerothermoelastic analysis
【摘要】高超声速气动热弹性分析涉及流场、结构场和热力场间的相互耦合，计算复杂且耗时长。根据分层求解策略提出了一种基于降阶模型的高超声速气动热弹性分析框架。分别采用系统辨识法和本征正交分解法对高超声速气动力和气动热建立降阶模型，并与模态叠加法耦合实现热配平状态下气动热弹性问题的快速计算。以典型高超声速三维机翼为例，**热结构的颤振动压，并与全阶流-固-热耦合计算结果对比吻合较好。所提出的气动热弹性分析框架提高了计算效率，而且精度高，可应用于工程分析中。
【abstract】aerothermoelastic analysis of hypersonic vehicle involves the coupling of fluid field, structural field, and thermodynamic field, and as a result is complicated and time-consuming. in this **a hypersonic aerothermoelastic analysis method based on reduced-order models is developed according to the hierarchical solution strategy. the system identification method and the proper orthogonal decomposition method are used to establish the reduced-order models of the hypersonic aerodynamic force and aerodynamic heating, respectively. then, these reduced-order models are combined with the modal superposition method to realize the rapid calculation of aerothermoelastic problems under the static aerothermoelastic trim. taking a typical hypersonic three-dimensional wing as an example, the dynamic pressure of flutter of the thermal structure is predicted, and is in good agreement with the calculation of the full-order fluid–solid–thermal coupling model. the aerothermoelastic analysis framework proposed in this **is accurate and greatly improves the calculation efficiency, which can be applied to the engineering analysis.
声学黑洞原理的双层加筋板-腔系统降噪研究。
noise reduction of a double-layer stiffened plate-c**ity system based on acoustic black hole principle
【摘要】双层加筋板在现代交通运输工具中被广泛应用，这类结构的声振抑制问题一直是难点。声学黑洞（abh:acoustic black hole）作为一种新型的波操纵技术，为结构振动噪声控制提供了新思路。提出将abh应用于双层加筋板中，开发有良好机械特性，特别是能实现减振降噪的结构。设计含有abh的双层加筋板-腔系统，搭建实验平台并在点载荷激励下进行效果测试。结果表明截止频率以上腔体的宽频噪声可降低1.5～8 db。基于有限元方法建立耦合数值模型，多角度量化了系统的动力学特性，分析揭示了abh在腔室降噪中具有增加系统阻尼和降低内壁板和声腔的耦合强度的双重物理机制。针对降噪效果欠佳的低频段，提供优化设计方案，拓宽有效频率，实现了全频带的控制。进一步验证了复杂载荷作用下abh双层加筋板-腔声振系统的减噪普适性。
【abstract】the double-layer stiffened plate is widely used in modern transportation, the noise and vibration problems caused by such structures are still problems that people concerned. however, traditional control methods are difficult to meet the development needs of modern equipment due to their large additional weight, low reliability and narrow effective frequency band. acoustic black hole (abh), as a new type of w**e manipulation technology, provides new ideas for vibration and noise reduction in the equipment. in this **abh is applied to a double-layer stiffened plate to develop a structure with good mechanical properties, especially to reduce vibration and noise. a double layer stiffened plate-c**ity system with abhs is designed, and an experimental platform is built to test the effect. the results show that the broadband noise of the c**ity can be reduced by 1.5–8 db above cutoff frequency. a coupled numerical model is established based on finite elements, and the physical mechanism behind noise reduction is analyzed by quantifying the dynamic characteristics of the system from multiple angles. it can be seen that the abh effect has dual characteristics in noise reduction, that is, increasing the damping of the system and reducing the coupling strength between inner-plate and c**ity. furthermore, the optimized design schemes are provided for the low frequency with poor noise reduction, widen the effective frequency and realize the control of the full-band. finally, the universality of the noise reduction under complex loads is verified and analyzed.
梯形和三角形波纹夹芯板的声振特性研究。
vibro-acoustic characteristics of trapezoidal and triangular corrugated sandwich panels
【摘要】研究了梯形和三角形两种类型波纹夹芯板的声振特性。将波纹芯层等效为各向异性均质体，采用双曲正切抛物线混合变形理论（htpsdt）建立了四边简支条件下波纹夹芯板的动力学方程和简谐声压激励下的声振耦合控制方程。利用纳维法和流固耦合界面条件进行求解，计算了梯形和三角形波纹夹芯板的固有频率和隔声量，并与有限元模拟结果进行对比，验证了理论模型的正确性，比较了两种波纹夹芯板的振动特点和隔声性能。讨论了波纹芯层结构参数变化对梯形和三角形波纹夹芯板振动和隔声特性的影响。结果表明，波纹倾角、波纹壁厚、波纹芯层高度对梯形和三角形波纹夹芯板的声振特性有着重要的影响，而且对三角形波纹夹芯板的影响更为显著。
【abstract】this **studies the vibro-acoustic characteristics of trapezoidal corrugated sandwich panels and triangular corrugated sandwich panels. the corrugated core is equivalent to an anisotropic homogeneous body. the dynamic equation of the sandwich panel with four-side **support and the vibro-acoustic coupling control equation under the excitation of the **harmonic pressure are established by using the hyperbolic tangent parabola deformation theory (htpsdt). the natural frequency and the sound insulation of trapezoid and triangular corrugated sandwich panels are obtained by using the n**ier method and the fluid-solid coupling interface condition. by comparing the calculated results with the finite element simulation results, the correctness of the theoretical model is verified. the vibration characteristics and sound insulation performance of the two types of corrugated sandwich panels are also compared. finally, the influence of the structural parameters of the corrugated core on the vibration and sound insulation characteristics of the trapezoid and triangular corrugated sandwich panels are discussed. according to the results, the dip angle of the corrugations, the corrugated wall thickness, and the height of the corrugated core can significantly influence the vibro-acoustic characteristics of the two types of panels, and the influence on the triangular corrugated sandwich panels is more pronounced.
具有深度亚波长厚度的共面可调完美吸声板。
a tunable coplanar perfect sound-absorbing panel with deep subw**elength thickness
【摘要】针对具有深度亚波长厚度的声学超构吸声板，研究了其声学特性和物理吸声机制，以及进一步提高其低频声学特性的可能性。该吸声板单元通过将带有小孔的分隔板内置于以阿基米德螺旋形成的共面腔体中形成双层穿孔吸声体结构。研究表明，通过调整分隔板在腔体中的位置，可以在较宽的频带范围内改变吸声板的共振频率，而不改变其近似完美吸声的声学性能。对该吸声板建立了完整的用于描述其声学特性的理论模型，并通过数值模拟的方法揭示了其物理吸声机制。同时，研究并分析了吸声板结构参数对其声学特性的影响，为进一步改善其低频声学性能提供了基础。为了验证研究结论的有效性，采用3d打印技术对所设计的样品进行打印，测量结果与理论计算和数值模拟得到的结果具有很好的一致性。与未加入分隔板的吸声结构相比，该吸声板可以在更低的频率下获得近全吸声的效果。
【abstract】the acoustic characteristics and physical absorption mechanism of the sound-absorbing panel with deep subw**elength thickness are studied, and the possibility of further improving its low-frequency performance is also discussed. the absorber unit is a double-layer perforated panel absorber that is constructed by inserting a separating plate with small holes into the coplanar c**ity based on the archimedean spiral. by adjusting the location of the separating plate in the c**ity, it is found that the resonance frequency of the absorber can be easily tuned over a large bandwidth while structural parameters are fixed, without changing its near-total absorption properties. a complete mathematical model of the absorbing panel that describes its absorption characteristics is derived, and the physical absorption mechanism of the panel is also revealed by numerical simulation. meanwhile, the effect of structural parameters on the absorption characteristics is also investigated, which provides a basis for further improving its low-frequency performance. to verify the validity of the conclusions, designed samples are fabricated by 3d printing, and the results are all in good agreement. compared with the previous techniques, near-total absorption can be achieved at a lower frequency.
期刊推荐·recommend journal
振动工程学报》是由中国振动工程学会主办，中国科协主管，南京航空航天大学出版的全国性核心期刊，创刊于2023年。主要反映我国振动工程的最新研究成果，评介最新科技成就，增强国内外学术信息交流，并鼓励首创精神，倡导优良学风，扶植、推荐优秀人才和作品，为推动振动工程学科的发展，促进我国的社会主义经济建设服务。本刊面向工程实际，理论与实际并重，主要刊登：振动理论与应用，非线性振动，随机振动，模态分析与试验，结构动力学，转子动力学，故障诊断，振动、冲击与噪声控制，动力稳定性，流固耦合振动，动态测试，动态信号分析，机械动力学，土动力学，包装动力学和结构抗震控制等方面的专题**、综合评述和研究简报。
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