离散非均匀约束的加筋结构振声学分析及阻尼优化
发布时间：2019-02-28 13:09
【摘要】：轻质板（壳）及其加筋结构广泛运用于工程结构、载运工具及国防现代化装备等领域。在受外部环境及工作载荷，或结构本身动力传递激励下，板（壳）构件将产生振动，并与流质发生耦合作用，向外部环境及(载运)舱内辐射噪声。结构振动与声辐射一方面造成结构的疲劳破坏，另一方面严重影响载运工具驾乘舒适性。理论研究与工程运用对结构振、噪机理及其抑减已有深入讨论，然而由于现代先进连接技术的发展和运用，板（壳）及其加筋结构的工作边界约束状态并非总是连续均匀形式，诸如点焊连接、铆接连接等空间分布不连续边界约束以及胶接等弱刚度“欠约束”的工程应用日益广泛，从而给相关结构的振声学特性分析及设计提出了新的课题。同时，被动阻尼减振降噪技术研究与工程运用方兴未艾，约束阻尼处理(CLD)形式简单，造价低廉，对轻质结构的振动和噪声抑减效果明显。然而，由于振声学问题结构边界条件的复杂化，应用CLD进行减振降噪设计随着结构振动和声辐射特性的变化而需进行“再优化”。 本文将实际工程结构不连续边界约束的板（壳）振声学分析及阻尼(CLD)优化设计问题，提取为本文的研究问题，探讨了考虑结构边界条件离散非均匀性的矩形平板及其加筋结构的振动控制方程的建立方法；推导了将物理坐标系内任意直四边形变换为计算坐标系下等参元正方形的所谓“等参变换”关系，从而使得任意直四边形结构的振声学特性分析及优化设计可以归结为相应正方形变换元的振声学问题；在运用Rayleigh-Ritz方法解析矩形平板及其加筋结构固有振动特性进及其振声学响应特性的基础上，针对在结构表面布置CLD的减振降噪处理形式，，采用GA-SQP混合优化算法，对具有连续/离散边界约束，受不同性质载荷激励下结构振动响应和声辐射进行约束优化设计，最后讨论了阻尼分布优化结果与边界条件及载荷激励特性的关系。本文开展的对一类具有复杂边界约束结构的振声学特性的分析及阻尼(CLD)减振降噪优化设计对于相关理论研究及工程实践运用具有一定的借鉴意义。
[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.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB123
本文编号：2431824
[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.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB123
【参考文献】
相关期刊论文 前4条
1 黎胜,赵德有;加筋板结构声传输研究[J];船舶力学;2001年04期
2 谢官模,李军向,罗斌,骆东平;环肋、舱壁和纵骨加强的无限长圆柱壳在水下的声辐射特性[J];船舶力学;2004年02期
3 徐赵东,周洲,赵鸿铁,沈亚鹏;粘弹性阻尼器的计算模型[J];工程力学;2001年06期
4 徐赵东,周云,周福霖;粘弹性阻尼器三种计算模型的对比与分析[J];华南建设学院西院学报;1999年02期
本文编号：2431824
本文链接：https://www.wllwen.com/guanlilunwen/gongchengguanli/2431824.html
