本文關(guān)鍵詞： 聲學(xué)超材料板 粘彈性 可變形 帶隙 減振 振動(dòng)實(shí)驗(yàn)　出處：《哈爾濱工業(yè)大學(xué)》2017年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：聲學(xué)超材料是近些年出現(xiàn)的一種周期性人工復(fù)合結(jié)構(gòu),在某些特殊頻段會(huì)出現(xiàn)負(fù)的等效參數(shù),這些頻段被稱(chēng)為帶隙。帶隙的存在使得聲學(xué)超材料在低頻降噪方面相比于傳統(tǒng)的隔音材料具備明顯優(yōu)勢(shì),但也存在帶隙的范圍較窄的問(wèn)題。在聲學(xué)超材料的發(fā)展過(guò)程中,聲學(xué)超材料板由于其輕質(zhì)、可承載、易于得到負(fù)等效參數(shù)的特點(diǎn)受到了廣泛關(guān)注,并在近些年得到了很大發(fā)展,但帶隙范圍窄的問(wèn)題依然存在。本文提出了一種可變形聲學(xué)超材料板的方案,研究如何利用質(zhì)量塊變形來(lái)拓寬聲學(xué)超材料板的頻率帶隙,并探究帶隙與其減振性能之間的聯(lián)系,這對(duì)于推動(dòng)薄膜型聲學(xué)超材料在減振領(lǐng)域的發(fā)展和應(yīng)用具有重要意義。首先,使用有限元軟件分別對(duì)質(zhì)量塊變形前、后的聲學(xué)超材料板進(jìn)行能帶結(jié)構(gòu)和振動(dòng)傳輸損耗的仿真計(jì)算,發(fā)現(xiàn)質(zhì)量塊的變形可以使帶隙的位置和寬度發(fā)生偏移,且聲學(xué)超材料板對(duì)頻率處于帶隙范圍內(nèi)的振動(dòng)具有較強(qiáng)的衰減能力,頻率帶隙和減振性能之間存在對(duì)應(yīng)關(guān)系。進(jìn)一步分析橡膠薄膜的預(yù)拉伸量、質(zhì)量塊的附著面積對(duì)于聲學(xué)超材料板帶隙位置和寬度的影響,根據(jù)變化規(guī)律對(duì)方案進(jìn)行改進(jìn)、優(yōu)化。然后,使用分?jǐn)?shù)階Kelvin-Voigt模型對(duì)橡膠的粘彈性本構(gòu)模型進(jìn)行描述,將橡膠薄膜視為粘彈性矩形板對(duì)其振動(dòng)方程進(jìn)行推導(dǎo),獲得了振動(dòng)方程的解析解。通過(guò)動(dòng)態(tài)頻率掃描實(shí)驗(yàn),發(fā)現(xiàn)橡膠薄膜彈性模量會(huì)隨振動(dòng)頻率的增長(zhǎng)而變大,并根據(jù)實(shí)驗(yàn)數(shù)據(jù)對(duì)聲學(xué)超材料板的能帶結(jié)構(gòu)進(jìn)行了仿真分析,發(fā)現(xiàn)隨著薄膜彈性模量的增大,帶隙出現(xiàn)的位置會(huì)變高,帶隙寬度會(huì)先變大后變小。最后,根據(jù)設(shè)計(jì)方案制作了兩個(gè)聲學(xué)超材料板來(lái)模擬質(zhì)量塊變形前后的狀態(tài),進(jìn)行了振動(dòng)實(shí)驗(yàn),獲得了相應(yīng)的頻率響應(yīng)曲線(xiàn)。實(shí)驗(yàn)結(jié)果對(duì)比表明,質(zhì)量塊變形后的減振能力強(qiáng)于質(zhì)量塊變形前的狀態(tài),且都能對(duì)頻率處于帶隙范圍內(nèi)的振動(dòng)進(jìn)行較強(qiáng)的衰減。
[Abstract]:Acoustic supermaterial is a kind of periodic artificial composite structure which appears in recent years and has negative equivalent parameters in some special frequency bands. These bands are called band gaps. The existence of band gaps makes acoustic supermaterials have obvious advantages over traditional acoustic insulation materials in low-frequency noise reduction. However, there is also a narrow band gap. In the development of acoustic metamaterials, the characteristics of acoustic metamaterials are easy to get negative equivalent parameters due to their lightweight, load-bearing. In recent years, great progress has been made, but the problem of narrow band gap still exists. In this paper, a deformable acoustic supermaterial plate scheme is proposed. This paper studies how to use mass block deformation to widen the frequency band gap of acoustic metamaterials and to explore the relationship between the band gap and its vibration absorption performance. It is of great significance to promote the development and application of thin film acoustic supermaterials in the field of vibration absorption. Firstly, the finite element software is used to deform the mass blocks. The energy band structure and vibration transmission loss of the acoustic supermaterial plate are simulated and calculated. It is found that the deformation of the mass block can offset the position and width of the band gap. The acoustic supermaterial plate has a strong attenuation ability to the vibration in the frequency band gap range, and there is a corresponding relationship between the frequency band gap and the vibration absorption performance. The influence of the attachment area of the mass block on the position and width of the band gap of the acoustic supermaterial plate is improved and optimized according to the changing law. The viscoelastic constitutive model of rubber is described by fractional Kelvin-Voigt model, and the vibration equation of rubber film is deduced as a viscoelastic rectangular plate. The analytical solution of the vibration equation is obtained. Through the dynamic frequency scanning experiment, it is found that the elastic modulus of the rubber film increases with the increase of the vibration frequency. According to the experimental data, the band structure of the acoustic supermaterial plate is simulated and analyzed. It is found that with the increase of the elastic modulus of the film, the position of the band gap will become higher, and the width of the band gap will first become larger and then smaller. Finally. According to the design, two acoustic supermaterial plates are made to simulate the state of mass blocks before and after deformation. The vibration experiments are carried out and the corresponding frequency response curves are obtained. The damping capacity of mass blocks after deformation is stronger than that of mass blocks before deformation, and both of them can attenuate the vibration in the band gap range.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TB535.1;TB33
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本文編號(hào)：1467357