基于模态振型形状优化的结构声辐射控制  

Control of Structural Acoustic Radiation Based on Mode Shape Optimization

作　　者：臧献国[1] 于德介[1] 姚凌云[1] 郭建文[1] 

机构地区：[1]湖南大学汽车车身先进设计制造国家重点实验室,长沙410082

出　　处：《机械工程学报》2010年第9期73-78,共6页Journal of Mechanical Engineering

基　　金：国家高技术研究发展计划(863计划;2009AA04Z414);教育部长江学者与创新团队发展计划(5311050050037);湖南大学汽车车身先进设计制造国家重点实验室自主课题(60870002)资助项目

摘　　要：针对复杂结构形状难以参数化的问题,建立基于有限元网格的参数化形状优化模型,提出一种基于模态振型的结构形状优化方法以控制结构声辐射功率。该方法通过有限元法计算结构的振动特性,然后采用瑞利积分进行结构的声辐射分析,在此基础上,用一组模态振型绝对值线性组合定义修改区域的形状优化函数,以每阶模态振型贡献因子为设计变量,通过改变模态振型贡献因子来优化结构的形状,达到降低结构声辐射功率的目的。研究简谐激励力下的结构声辐射优化,以结构声辐射分析频率带内的辐射声功率均值为设计目标,结构有限元结构坐标的最大变动值及模态频率为设计约束,利用序列二次规划算法进行优化求解。以几何平板和复杂曲面为数值算例,研究结果表明该方法可以有效控制结构声辐射。Inview of the difficult parameterization problem of complex structural shape, a parameterized shape optimization model based on finite element meshes is built and a structural shape optimization method based on mode shape is proposed for controlling the structural acoustic radiation power. In this method, structural vibration characteristic analyed by using finite element method and then structural acoustic radiation is analyzed by using Rayleigh integral. On the basis, the shape optimization function of modification domain is defined by using a linear combination of a group of mode shape absolute values, and each mode shape contribution factor is taken as a design variable. The structural shape is optimized by changing the mode shape contribution factors to decrease the structural acoustic radiation power. Structural acoustic radiation optimization is studied under harmonic excitation, the average value of acoustic radiation power in the analysis frequency band acoustic radiation is taken as design objective, the maximum variable value of structural coordinates and mode frequency are taken as design constraints, and the problem is solved by using sequential quadratic programming. Numerical examples of a plate and complex surface are presented to show that structural acoustic radiation can be controlled effectively.

关 键 词：模态振型 形状优化 结构声辐射 

分 类 号：TB535[理学—物理]