【作者】 艾国庆；

【导师】 倪樵；

【作者基本信息】 华中科技大学 ， 固体力学， 2007， 硕士

【摘要】 复合材料的声辐射特性一直是国内外关注的热点。本文建立了纤维增强复合材料层合椭圆柱壳的数值计算模型,采用有限元/边界元法计算纤维增强复合材料层合椭圆柱壳的声辐射问题,首先利用有限单元法计算壳体受激励时的振动,然后提取表面单元数据及其法向位移,作为边界元模型和边界条件,从而可计算出壳体的辐射功率,表面、近场和远场声压,计算表明结构振动模态对于受激振动辐射声场具重要影响。分析模型在工程实际中有较广泛应用,为振动噪声控制与优化设计问题提供了一种方便有效的途径。本文还研究了由结构振动引起的低频车内噪声,以某简化车身模型为研究对象,建立结构与声学三维有限元模型,利用有限单元法计算车身受简谐激励时的振动,然后提取表面单元数据及其法向位移,作为边界元模型和边界条件,从而可计算出车内的声压大小,声场分布特性以及声贡献量分析。更多还原

【Abstract】 The characteristic of acoustic radiation from composite structures have been analysed by many authors. The paper describes a numerical model to calculate the acoustic radiation of fiber reinforced laminated composite elliptic cylindrical shell using FFM /BEM. Vibration of the shell excited by a point load is analysed by FEM firstly, then the mesh element information and normal displacement of the coupling surface are drawn out and set as the boundary condition of the BEM model. Based on this, the radiation sound power and sound pressure in field are given. It is shown that the coupling model have some influence on vibroacoustic radiation.The paper also focuses on vehicle interior noise at low frequency range caused by structural vibration, and taking a simplified car as example, the thesis uses a three dimensional model with the consideration of structure and acoustics coupling. Vibration of the car excited by a point load is analysed by FEM firstly, then the mesh element information and normal displacement of the coupling surface are drawn out and set as the boundary condition of the BEM model. Based on this, element acoustic contribution and sound pressure in field are given.更多还原