【摘要】：輕質(zhì)板（殼）及其加筋結(jié)構(gòu)廣泛運用于工程結(jié)構(gòu)、載運工具及國防現(xiàn)代化裝備等領(lǐng)域。在受外部環(huán)境及工作載荷，或結(jié)構(gòu)本身動力傳遞激勵下，板（殼）構(gòu)件將產(chǎn)生振動，并與流質(zhì)發(fā)生耦合作用，向外部環(huán)境及(載運)艙內(nèi)輻射噪聲。結(jié)構(gòu)振動與聲輻射一方面造成結(jié)構(gòu)的疲勞破壞，另一方面嚴(yán)重影響載運工具駕乘舒適性。理論研究與工程運用對結(jié)構(gòu)振、噪機理及其抑減已有深入討論，然而由于現(xiàn)代先進連接技術(shù)的發(fā)展和運用，板（殼）及其加筋結(jié)構(gòu)的工作邊界約束狀態(tài)并非總是連續(xù)均勻形式，諸如點焊連接、鉚接連接等空間分布不連續(xù)邊界約束以及膠接等弱剛度“欠約束”的工程應(yīng)用日益廣泛，從而給相關(guān)結(jié)構(gòu)的振聲學(xué)特性分析及設(shè)計提出了新的課題。同時，被動阻尼減振降噪技術(shù)研究與工程運用方興未艾，約束阻尼處理(CLD)形式簡單，造價低廉，對輕質(zhì)結(jié)構(gòu)的振動和噪聲抑減效果明顯。然而，由于振聲學(xué)問題結(jié)構(gòu)邊界條件的復(fù)雜化，應(yīng)用CLD進行減振降噪設(shè)計隨著結(jié)構(gòu)振動和聲輻射特性的變化而需進行“再優(yōu)化”。 本文將實際工程結(jié)構(gòu)不連續(xù)邊界約束的板（殼）振聲學(xué)分析及阻尼(CLD)優(yōu)化設(shè)計問題，提取為本文的研究問題，探討了考慮結(jié)構(gòu)邊界條件離散非均勻性的矩形平板及其加筋結(jié)構(gòu)的振動控制方程的建立方法；推導(dǎo)了將物理坐標(biāo)系內(nèi)任意直四邊形變換為計算坐標(biāo)系下等參元正方形的所謂“等參變換”關(guān)系，從而使得任意直四邊形結(jié)構(gòu)的振聲學(xué)特性分析及優(yōu)化設(shè)計可以歸結(jié)為相應(yīng)正方形變換元的振聲學(xué)問題；在運用Rayleigh-Ritz方法解析矩形平板及其加筋結(jié)構(gòu)固有振動特性進及其振聲學(xué)響應(yīng)特性的基礎(chǔ)上，針對在結(jié)構(gòu)表面布置CLD的減振降噪處理形式，，采用GA-SQP混合優(yōu)化算法，對具有連續(xù)/離散邊界約束，受不同性質(zhì)載荷激勵下結(jié)構(gòu)振動響應(yīng)和聲輻射進行約束優(yōu)化設(shè)計，最后討論了阻尼分布優(yōu)化結(jié)果與邊界條件及載荷激勵特性的關(guān)系。本文開展的對一類具有復(fù)雜邊界約束結(jié)構(gòu)的振聲學(xué)特性的分析及阻尼(CLD)減振降噪優(yōu)化設(shè)計對于相關(guān)理論研究及工程實踐運用具有一定的借鑒意義。
[Abstract]:Lightweight panels (shells) and their stiffened structures are widely used in engineering structures, transport tools and modern national defense equipment. Under the excitation of external environment and working load, or the dynamic transfer of the structure itself, the plate (shell) member will produce vibration and coupling with the fluid, and radiate noise to the external environment and to the (carrying) cabin. Structural vibration and acoustic radiation on the one hand cause structural fatigue damage, on the other hand, seriously affect the ride comfort of carrier tools. Theoretical research and engineering application have been deeply discussed on the vibration, noise mechanism and suppression of structural vibration. However, due to the development and application of modern advanced connection technology, the working boundary constraint state of plate (shell) and reinforced structure is not always in a continuous and uniform form. Engineering applications of spatial discontinuity boundary constraints such as spot welding joints, riveting joints and weak stiffness "underconstraints" such as adhesive joints are becoming more and more popular. Therefore, new topics have been proposed for the analysis and design of vibro-acoustic characteristics of related structures. At the same time, the research and engineering application of passive damping and noise reduction technology is in the ascendant, the (CLD) form of constrained damping treatment is simple, the cost is low, and the effect of reducing vibration and noise of light-weight structure is obvious. However, due to the complexity of the boundary conditions of vibration and acoustics problems, the design of vibration reduction and noise reduction based on CLD needs to be "reoptimized" with the change of structural vibration and acoustic radiation characteristics. In this paper, the vibration acoustic analysis of plates and shells with discontinuous boundary constraints and the optimal design of damping (CLD) for practical engineering structures are extracted as the research problems of this paper. The method of establishing the governing equations of the rectangular plate and its stiffened structure considering the discrete and non-uniform boundary conditions of the structure is discussed in this paper. The so-called "isoparametric transformation" relation of the square of isoparametric element in the physical coordinate system is derived. Therefore, the analysis and optimization of the vibration-acoustics characteristics of arbitrary quadrilateral structures can be reduced to the vibration-acoustics problems of the corresponding square transformation elements. On the basis of analyzing the inherent vibration characteristics of rectangular plate and its stiffened structures by using Rayleigh-Ritz method, the hybrid optimization algorithm of GA-SQP is adopted to deal with the vibration and noise reduction of the rectangular plate and its stiffened structures, which are arranged on the surface of the structure in the form of vibration absorption and noise reduction. The optimal design of structural vibration response and acoustic radiation with continuous / discrete boundary constraints under different kinds of loads is carried out. Finally, the relationship between the optimal results of damping distribution and the boundary conditions and the characteristics of load excitation is discussed. The analysis of the vibration and acoustics characteristics of a class of structures with complex boundary constraints and the optimal design of damping (CLD) for vibration and noise reduction have certain reference significance for the related theoretical research and engineering practice.
【學(xué)位授予單位】：上海交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TB123

【參考文獻】

相關(guān)期刊論文 前4條

1 黎勝,趙德有;加筋板結(jié)構(gòu)聲傳輸研究[J];船舶力學(xué);2001年04期

2 謝官模,李軍向,羅斌,駱東平;環(huán)肋、艙壁和縱骨加強的無限長圓柱殼在水下的聲輻射特性[J];船舶力學(xué);2004年02期

3 徐趙東,周洲,趙鴻鐵,沈亞鵬;粘彈性阻尼器的計算模型[J];工程力學(xué);2001年06期

4 徐趙東,周云,周福霖;粘彈性阻尼器三種計算模型的對比與分析[J];華南建設(shè)學(xué)院西院學(xué)報;1999年02期

本文編號：2431824