發(fā)布時間：2018-10-19 20:43

【摘要】：作為當(dāng)前國際上新一代先進輕質(zhì)、超強韌結(jié)構(gòu),周期格柵及其夾層結(jié)構(gòu)在車輛交通、航空航天、船舶、武器裝備等領(lǐng)域有著廣泛而重要的應(yīng)用前景。有效抑制周期格柵及其夾層結(jié)構(gòu)中彈性波的傳播對其減振降噪具有重要意義。彈性波傳播特性的調(diào)控為周期格柵及其夾層結(jié)構(gòu)減振降噪特性設(shè)計提供了新的解決路徑。在國家自然科學(xué)基金等項目的資助下,本文圍繞周期格柵及其夾層結(jié)構(gòu)在減振降噪應(yīng)用方面所面臨的關(guān)鍵理論和技術(shù)問題展開深入研究,為其減振降噪設(shè)計提供技術(shù)支持。論文主要研究內(nèi)容包括:周期格柵及其夾層結(jié)構(gòu)的彈性波傳播特性計算方法;周期格柵及其夾層結(jié)構(gòu)的彈性波傳播特性及其影響因素分析;含壓電分流電路的周期梁和格柵結(jié)構(gòu)的彈性波傳播特性及其影響因素分析。論文的主要創(chuàng)新成果包括:1.研究了負(fù)泊松比周期格柵結(jié)構(gòu)的帶隙特性和傳播方向性。深入分析了兩種典型負(fù)泊松比周期格柵結(jié)構(gòu)的材料參數(shù)和幾何參數(shù)對其帶隙特性的調(diào)控規(guī)律,揭示了其帶隙形成的機理,證實了負(fù)泊松比周期格柵結(jié)構(gòu)較傳統(tǒng)周期格柵結(jié)構(gòu)形成的帶隙更寬、帶隙頻段更低,對原胞結(jié)構(gòu)的幾何尺寸和拓?fù)錁?gòu)型進行優(yōu)化設(shè)計提高了周期格柵結(jié)構(gòu)中彈性波的衰減性能。2.研究了周期格柵加筋板結(jié)構(gòu)和周期格柵夾層板結(jié)構(gòu)的帶隙特性。證實了單蒙皮與加筋、雙蒙皮與夾芯層之間耦合作用的強弱影響帶隙的產(chǎn)生和帶隙的寬度,具體來說:(1)當(dāng)蒙皮厚度與加筋高度之比較小時,耦合作用較弱,格柵加筋決定了整個結(jié)構(gòu)的帶隙特性;隨著蒙皮厚度與加筋高度之比逐漸增大,產(chǎn)生逐漸增寬的帶隙,帶隙寬度達(dá)到最大值之后又逐漸變窄;當(dāng)蒙皮厚度與加筋厚度相當(dāng)時,耦合作用更強,結(jié)構(gòu)帶隙特性基本呈現(xiàn)均質(zhì)板的特征。(2)相對于周期格柵加筋板結(jié)構(gòu),周期格柵夾層結(jié)構(gòu)中雙層蒙皮與夾芯層的耦合作用更強,布拉格散射機理對結(jié)構(gòu)中彈性波傳播特性的調(diào)控作用更弱。3.開展了基于壓電分流電路的周期格柵結(jié)構(gòu)減振設(shè)計探索研究。系統(tǒng)分析了諧振式、增強諧振式、反饋式壓電分流電路對周期梁和格柵結(jié)構(gòu)帶隙特性調(diào)控機理及其影響規(guī)律:(1)采用諧振式壓電分流電路可實現(xiàn)與局域共振帶隙同樣的低頻帶隙,其帶隙生成沒有引入機械振子,同時具有附加質(zhì)量小、帶隙可調(diào)的優(yōu)點;采用增強諧振式壓電分流電路可進一步加寬局域共振帶隙,增大帶隙附近的振動衰減。(2)采用反饋式壓電分流電路,帶隙內(nèi)和帶隙外的彈性波傳播的衰減均顯著增強。(3)初步探索了諧振式壓電分流電路對周期格柵結(jié)構(gòu)中彈性波傳播特性的調(diào)控。這些研究工作為周期格柵及其夾層結(jié)構(gòu)低頻振動主動控制提供技術(shù)支持。總之,本文主要針對周期格柵及其夾層結(jié)構(gòu)在減振降噪應(yīng)用方面需要解決的關(guān)鍵理論與技術(shù)問題展開深入研究:建立了并完善了適用于周期格柵及其夾層結(jié)構(gòu)的彈性波傳播特性計算方法;深入揭示了周期格柵結(jié)構(gòu)、周期格柵加筋板結(jié)構(gòu)、周期格柵夾層板結(jié)構(gòu)以及含壓電分流電路的周期梁結(jié)構(gòu)和格柵結(jié)構(gòu)彈性波傳播特性與調(diào)控規(guī)律。這些研究成果進一步深化和拓展了周期結(jié)構(gòu)彈性波傳播理論,為滿足工程應(yīng)用的周期格柵及其夾層結(jié)構(gòu)的減振降噪設(shè)計提供了若干理論基礎(chǔ)和技術(shù)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.
【學(xué)位授予單位】：國防科學(xué)技術(shù)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：TB535

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相關(guān)期刊論文 前1條

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本文編號：2282311