【毕业论文标题】 基于VA One的声结构优化系统的二次开发
【英文标题】 Secondary Development of Structural Vibration-acoustic Optimization Based on VA One
【中文摘要】 随着科学技术的发展,人类实践活动的范围大大扩展,从陆到海从地到天,面临各种各样的新环境,结构声振现象对人类活动造成极大影响。目前人们对声振要求主要体现在三个方面:首先,声振对人的心理和生理有害,影响正常的生活、工作和身体健康;其次,声振问题在军事对抗、科学探测等发现识别方面需求旺盛;第三,声振可加速结构、仪器疲劳损伤,导致其运行可靠性降低,使用寿命缩短。研究声振问题目的就是趋利避害,服务于民生和国防建设。目前计算机数值方法模拟仿真成为了科学研究的重要手段。VA One是个融合多种数值方法的全频域声振仿真软件。本文在该声振软件平台下,对某航天结构进行声振分析,对比了统计能量法和有限元方法的优缺点,展示了多数值方法联合应用解决结构振动声场的意义。在声结构分析基础上,对VA One进行二次开发,增加了声结构优化设计的功能。该二次开发采用Matlab语言,并借助了MATLAB软件包,搭建了一个可扩展的软件开发框架,考虑了将来的VA One软件的功能扩展。声振计算和优化程序的开发涉及面广,为方便各个功能模块的合成和数据交换,采用独立数据格式,提供了一种松耦合的方式,便于专业人员专注于自己的功能模块和不同功能模块人员之间的互相协作,相互配合。最后通过飞行器和汽车模型的隔声层优化算例展示了程序的有效性和运行正确性。程序的不足是没有实现有限元和边界元的优化功能,这是由于当前的VA One软件只能正确提供统计能量法的接口。这将在未来的开发中增补

【英文摘要】 With the development of science and technology,human practice extends widely and largely from land to sea and ground to sky,suffering a variety of new environments.The phenomena of the structure of vibration noise have a big influence on human activities and there are great demands in the following three aspects to people at present.Firstly,vibration noise are harmful to mental and physical states and have an adverse effect on the normal life, work and health.Secondly,there are a strong demand of the solutions of vibration-acoustic problems of detection and identification in military confrontation and scientific exploration. Thirdly,vibration noise can speed up the progress of structures' and equipments' fatigue and damage and failure,resulting in reduced work reliability and shortening their service life.The purpose of study on sound and vibration is to go after profits and avoid disadvantages,to serve the national economy and the people's livelihood.At present,computer numerical simulation is becoming an important means of scientific research.VA One is a full-frequency-domain vibration-acoustic simulation software that integrates a variety of numerical methods.In this paper,an example of vibration-acoustic analysis of an aircraft is given under VA One platform and the advantages of integration application of several numerical methods is shown by comparing the merits of numerical methods.VA One secondary development is done based on analysis functions and enriches VA One with optimization function.It builds an extensible framework for software development by means of M language and using the MATLAB software package,considering its extensibility in the future.The development of vibration-acoustic simulation covers a wide scope of fields and it is difficulty for an individual to master all the aspects of development. An independent data format in use brings up a loosely coupled method that is convenient for professionals to focus on their individual areas and to cooperate with each others to work between specialized fields.At last,an optimization example displays the correct running and the effectiveness of programming.The optimization example of sound insulating layer of an aircraft displays that the five-layer structure can get a better result than the three-layer one and shows the validity and the necessity of optimization.The deficiency of programming is that it has not included the optimization features of the finite element method and the boundary element method, because of the limit of software version,which will be overcome in the future development.The project of the research presented in this paper is supported by the National Natural Science Foundation of China(10772038,10728205).
【中文关键词】 优化; 程序设计; VA One软件; Matlab软件; 声振
【英文关键词】 Optimization; Programming; VA One; Matlab; Sound and Vibration

【论文目录】
摘要 4-5
Abstract 5-6
1 绪论 9-13
    1.1 声—结构系统的概述 9-10
    1.2 声—结构系统的数值模拟 10-11
    1.3 声—结构系统的全频域分析及优化 11-12
    1.4 课题的目的及本文的主要研究内容 12-13
2 声振动理论基础及声结构 13-22
    2.1 振动理论 13-14
    2.2 声学基础 14-16
        2.2.1 声波的传播与声学的基本假定 14-15
        2.2.2 声学的常用度量 15-16
        2.2.3 材料的声特性参数 16
    2.3 声波的基本方程 16-17
    2.4 吸声与隔声 17-22
        2.4.1 吸声与隔声的基本概念 17-18
        2.4.2 吸声材料和吸声结构 18-20
        2.4.3 隔声材料、隔声结构及阻尼材料 20-22
3 声—结构系统的计算方法 22-29
    3.1 基本计算理论介绍 22-27
        3.1.1 统计能量分析法 22-24
        3.1.2 有限单元法 24-26
        3.1.3 边界元 26-27
    3.2 计算理论的适用性与比较 27-29
4 VA One软件的工程实例分析 29-40
    4.1 航天飞行器仿真分析建模 29-35
    4.2 有限元和统计能量法的混合仿真 35-40
5 VA One软件平台优化二次开发 40-49
    5.1 优化程序框架及实现方法 40-41
    5.2 程序流程说明 41-42
    5.3 程序数据格式说明 42-43
    5.4 飞行器隔声层优化 43-46
        5.4.1 五层隔声材料层的优化设计 44-45
        5.4.2 三层隔声材料层的优化设计 45-46
    5.5 汽车发动机隔声结构优化 46-49
结论 49-50
参考文献 50-52
攻读硕士学位期间发表学术论文情况 52-53
致谢 53-54