周期格栅及其夹层结构弹性波传播特性研究
发布时间：2018-10-19 20:43
【摘要】：作为当前国际上新一代先进轻质、超强韧结构,周期格栅及其夹层结构在车辆交通、航空航天、船舶、武器装备等领域有着广泛而重要的应用前景。有效抑制周期格栅及其夹层结构中弹性波的传播对其减振降噪具有重要意义。弹性波传播特性的调控为周期格栅及其夹层结构减振降噪特性设计提供了新的解决路径。在国家自然科学基金等项目的资助下,本文围绕周期格栅及其夹层结构在减振降噪应用方面所面临的关键理论和技术问题展开深入研究,为其减振降噪设计提供技术支持。论文主要研究内容包括:周期格栅及其夹层结构的弹性波传播特性计算方法;周期格栅及其夹层结构的弹性波传播特性及其影响因素分析;含压电分流电路的周期梁和格栅结构的弹性波传播特性及其影响因素分析。论文的主要创新成果包括:1.研究了负泊松比周期格栅结构的带隙特性和传播方向性。深入分析了两种典型负泊松比周期格栅结构的材料参数和几何参数对其带隙特性的调控规律,揭示了其带隙形成的机理,证实了负泊松比周期格栅结构较传统周期格栅结构形成的带隙更宽、带隙频段更低,对原胞结构的几何尺寸和拓扑构型进行优化设计提高了周期格栅结构中弹性波的衰减性能。2.研究了周期格栅加筋板结构和周期格栅夹层板结构的带隙特性。证实了单蒙皮与加筋、双蒙皮与夹芯层之间耦合作用的强弱影响带隙的产生和带隙的宽度,具体来说:(1)当蒙皮厚度与加筋高度之比较小时,耦合作用较弱,格栅加筋决定了整个结构的带隙特性;随着蒙皮厚度与加筋高度之比逐渐增大,产生逐渐增宽的带隙,带隙宽度达到最大值之后又逐渐变窄;当蒙皮厚度与加筋厚度相当时,耦合作用更强,结构带隙特性基本呈现均质板的特征。(2)相对于周期格栅加筋板结构,周期格栅夹层结构中双层蒙皮与夹芯层的耦合作用更强,布拉格散射机理对结构中弹性波传播特性的调控作用更弱。3.开展了基于压电分流电路的周期格栅结构减振设计探索研究。系统分析了谐振式、增强谐振式、反馈式压电分流电路对周期梁和格栅结构带隙特性调控机理及其影响规律:(1)采用谐振式压电分流电路可实现与局域共振带隙同样的低频带隙,其带隙生成没有引入机械振子,同时具有附加质量小、带隙可调的优点;采用增强谐振式压电分流电路可进一步加宽局域共振带隙,增大带隙附近的振动衰减。(2)采用反馈式压电分流电路,带隙内和带隙外的弹性波传播的衰减均显著增强。(3)初步探索了谐振式压电分流电路对周期格栅结构中弹性波传播特性的调控。这些研究工作为周期格栅及其夹层结构低频振动主动控制提供技术支持。总之,本文主要针对周期格栅及其夹层结构在减振降噪应用方面需要解决的关键理论与技术问题展开深入研究:建立了并完善了适用于周期格栅及其夹层结构的弹性波传播特性计算方法;深入揭示了周期格栅结构、周期格栅加筋板结构、周期格栅夹层板结构以及含压电分流电路的周期梁结构和格栅结构弹性波传播特性与调控规律。这些研究成果进一步深化和拓展了周期结构弹性波传播理论,为满足工程应用的周期格栅及其夹层结构的减振降噪设计提供了若干理论基础和技术支持。
[Abstract]:As a new generation of advanced lightweight, super-tough structure, the cycle grid and its sandwich structure have a wide and important application prospect in the fields of vehicle transportation, aerospace, ship, weaponry and so on. It is of great significance to effectively inhibit the propagation of elastic wave in the periodic grid and its sandwich structure. The control of elastic wave propagation characteristic provides a new solution path for the design of periodic grid and sandwich structure vibration reduction and noise reduction. With the support of NSFC and other projects, this paper studies the key theories and technical problems in vibration reduction and noise reduction applications around periodic grid and its sandwich structure, and provides technical support for its vibration reduction and noise reduction design. The main research contents include: the calculation method of elastic wave propagation characteristic of periodic grid and its sandwich structure, elastic wave propagation characteristic of periodic grid and its sandwich structure and its influencing factors; Analysis of elastic wave propagation characteristics of periodic beam and grid structure with piezoelectric shunt circuit and its influencing factors. The main innovative achievements of the thesis include: 1. The band gap characteristics and propagation directivity of the negative pole-grid structure are studied. In this paper, the material parameters and geometric parameters of two typical negative periodic grid structures are analyzed in this paper, and the regulation law of its band gap characteristics is analyzed. The mechanism of the band gap formation is revealed. It is confirmed that the grid structure of negative grid cycle is wider than that of the traditional periodic grid structure, and the band gap frequency band is lower. The optimized design of the geometry and topology of the original cell structure improves the attenuation performance of the elastic wave in the grid structure of the periodic grid. In this paper, the band gap characteristics of the grid-stiffened plate structure and the periodic grid sandwich plate structure are studied. It is confirmed that the coupling between the single skin and the reinforcement, the double skin and the sandwich layer affects the generation of the gap and the width of the band gap, and specifically, (1) when the thickness of the skin and the height of the reinforcement bar are relatively small, the coupling effect is weak, and the grid reinforcement determines the band gap characteristic of the whole structure; As the ratio of the thickness of the skin to the height of the reinforcement gradually increases, a gradually widened band gap is generated, and the width of the belt gap is gradually narrowed after the width of the belt gap reaches the maximum value; when the thickness of the skin is equivalent to the thickness of the reinforcing bar, the coupling action is stronger, and the structural belt gap property basically presents the characteristics of the homogeneous plate. (2) Compared with the grid-stiffened plate structure of the periodic grid, the coupling effect of the double-layer skin and the sandwich layer in the periodic grid sandwich structure is stronger, and the Bragg scattering mechanism is weaker than that of the elastic wave propagation characteristic in the structure. In this paper, a study on vibration reduction design of periodic grid structure based on piezoelectric shunt circuit is carried out. In this paper, the regulation mechanism of resonance type, reinforced resonance type and feedback type piezoelectric shunt circuit on the gap characteristic of periodic beam and grid structure and its influence law are analyzed: (1) The same low frequency band gap as local resonance band gap can be realized by adopting resonance type piezoelectric shunt circuit. The band gap generation does not introduce a mechanical vibrator, and has the advantages of small additional mass and adjustable band gap, and the local resonance band gap can be further widened by adopting the enhanced resonance type piezoelectric shunt circuit, and vibration attenuation in the vicinity of the band gap is enlarged. (2) With the feedback type piezoelectric shunt circuit, the attenuation of elastic wave propagation outside the band gap and the band gap is significantly enhanced. (3) Preliminary exploration of the regulation of the propagation characteristics of the elastic wave in the periodic grid structure by the resonant piezoelectric shunt circuit. These researches provide technical support for active control of low frequency vibration of periodic grid and sandwich structure. In summary, the key theories and technical problems which need to be solved in the application of vibration reduction and noise reduction are studied mainly in this paper. The calculation method of elastic wave propagation characteristics suitable for the periodic grid and its sandwich structure is established and perfected. In this paper, the periodic grid structure, the periodic grid-stiffened plate structure, the periodic grid sandwich plate structure and the periodic beam structure including the piezoelectric shunt circuit and the elastic wave propagation characteristics and regulation law of the grid structure are discussed in depth. The research results further deepen and expand the theory of periodic structure elastic wave propagation, and provide some theoretical bases and technical support for the design of vibration reduction and noise reduction of the periodic grid and its sandwich structure which can meet the engineering application.
【学位授予单位】：国防科学技术大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TB535
本文编号：2282311
[Abstract]:As a new generation of advanced lightweight, super-tough structure, the cycle grid and its sandwich structure have a wide and important application prospect in the fields of vehicle transportation, aerospace, ship, weaponry and so on. It is of great significance to effectively inhibit the propagation of elastic wave in the periodic grid and its sandwich structure. The control of elastic wave propagation characteristic provides a new solution path for the design of periodic grid and sandwich structure vibration reduction and noise reduction. With the support of NSFC and other projects, this paper studies the key theories and technical problems in vibration reduction and noise reduction applications around periodic grid and its sandwich structure, and provides technical support for its vibration reduction and noise reduction design. The main research contents include: the calculation method of elastic wave propagation characteristic of periodic grid and its sandwich structure, elastic wave propagation characteristic of periodic grid and its sandwich structure and its influencing factors; Analysis of elastic wave propagation characteristics of periodic beam and grid structure with piezoelectric shunt circuit and its influencing factors. The main innovative achievements of the thesis include: 1. The band gap characteristics and propagation directivity of the negative pole-grid structure are studied. In this paper, the material parameters and geometric parameters of two typical negative periodic grid structures are analyzed in this paper, and the regulation law of its band gap characteristics is analyzed. The mechanism of the band gap formation is revealed. It is confirmed that the grid structure of negative grid cycle is wider than that of the traditional periodic grid structure, and the band gap frequency band is lower. The optimized design of the geometry and topology of the original cell structure improves the attenuation performance of the elastic wave in the grid structure of the periodic grid. In this paper, the band gap characteristics of the grid-stiffened plate structure and the periodic grid sandwich plate structure are studied. It is confirmed that the coupling between the single skin and the reinforcement, the double skin and the sandwich layer affects the generation of the gap and the width of the band gap, and specifically, (1) when the thickness of the skin and the height of the reinforcement bar are relatively small, the coupling effect is weak, and the grid reinforcement determines the band gap characteristic of the whole structure; As the ratio of the thickness of the skin to the height of the reinforcement gradually increases, a gradually widened band gap is generated, and the width of the belt gap is gradually narrowed after the width of the belt gap reaches the maximum value; when the thickness of the skin is equivalent to the thickness of the reinforcing bar, the coupling action is stronger, and the structural belt gap property basically presents the characteristics of the homogeneous plate. (2) Compared with the grid-stiffened plate structure of the periodic grid, the coupling effect of the double-layer skin and the sandwich layer in the periodic grid sandwich structure is stronger, and the Bragg scattering mechanism is weaker than that of the elastic wave propagation characteristic in the structure. In this paper, a study on vibration reduction design of periodic grid structure based on piezoelectric shunt circuit is carried out. In this paper, the regulation mechanism of resonance type, reinforced resonance type and feedback type piezoelectric shunt circuit on the gap characteristic of periodic beam and grid structure and its influence law are analyzed: (1) The same low frequency band gap as local resonance band gap can be realized by adopting resonance type piezoelectric shunt circuit. The band gap generation does not introduce a mechanical vibrator, and has the advantages of small additional mass and adjustable band gap, and the local resonance band gap can be further widened by adopting the enhanced resonance type piezoelectric shunt circuit, and vibration attenuation in the vicinity of the band gap is enlarged. (2) With the feedback type piezoelectric shunt circuit, the attenuation of elastic wave propagation outside the band gap and the band gap is significantly enhanced. (3) Preliminary exploration of the regulation of the propagation characteristics of the elastic wave in the periodic grid structure by the resonant piezoelectric shunt circuit. These researches provide technical support for active control of low frequency vibration of periodic grid and sandwich structure. In summary, the key theories and technical problems which need to be solved in the application of vibration reduction and noise reduction are studied mainly in this paper. The calculation method of elastic wave propagation characteristics suitable for the periodic grid and its sandwich structure is established and perfected. In this paper, the periodic grid structure, the periodic grid-stiffened plate structure, the periodic grid sandwich plate structure and the periodic beam structure including the piezoelectric shunt circuit and the elastic wave propagation characteristics and regulation law of the grid structure are discussed in depth. The research results further deepen and expand the theory of periodic structure elastic wave propagation, and provide some theoretical bases and technical support for the design of vibration reduction and noise reduction of the periodic grid and its sandwich structure which can meet the engineering application.
【学位授予单位】：国防科学技术大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TB535
【参考文献】
相关期刊论文 前1条
1 卢天健;何德坪;陈常青;赵长颖;方岱宁;王晓林;;超轻多孔金属材料的多功能特性及应用[J];力学进展;2006年04期
，本文编号：2282311
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