【作者】 李坤朋；

【导师】 牛军川；

【作者基本信息】 山东大学 ， 机械设计及理论， 2013， 硕士

【摘要】 相对于传统有限元法及统计能量分析方法,能量有限元法因其在中高频的普遍适用性,以及可预示结构中某特定点的振动特性等优点,已经成为研究振动及噪声不可或缺的方法。本文以国家自然科学基金“基于功率流有限元分析的复杂柔性振动体系的智能控制研究”(No.50805088)和汽车仿真与控制国家重点实验室开放基金“汽车驾乘室振动噪声的功率流有限元分析及主动控制研究’(No.20091110)为基本课题来源,以不同耦合板结构为基本研究对象,重点讨论了能量有限元法在其结构中的应用。本文研究的主要内容及创新点主要包括如下几个方面。详细推导了薄板结构中弯曲、面内纵波及面内剪切波的控制方程,为后续章节建立能量平衡方程及计算能量传递系数提供最必要的基础条件。将不同耦合结构、不同激励情况下三个坐标轴方向上的振动位移表达式进行了整合,使其在计算时仅需删减相对应的项,从而使表达式具有相当的适应性。详细讨论了不同激励情况下能量传递系数随入射角度的变化趋势,以及频率对能量传递系数的影响。讨论了三种不同波型入射情况下耦合板结构能量密度分布情况,分析了激励频率及阻尼对能量密度分布的影响,并且讨论了在较低频率情况下面内波激励时能量有限元法的适用性问题,为确定该方法针对不同波型的频率适用范围提出了大胆的推测。讨论了弯曲激励情况下门型耦合板结构中弯曲波能量密度与总能量密度的差值,得出了在中间激励板上两者相差无几,两侧支撑板中面内波影响在频率不大情况下可以忽略的结论,这为计算时忽略面内波影响提供了最直接的依据。更多还原

【Abstract】 Energy Finite Element Method has become an essential method using to predict mechanical vibration and noise, for its advantages such as ubiquity in frequencies ranging from medium to high, and the ability that it can predict the vibration responses at any point we want, compared to the Finite Element Method and Statistical Energy Analysis. It took some different coupled-plate structures as the subjects in this paper which is supported by the project of National Natural Science Foundation of Chinese (NSFC)"The Intelligent Control Research of Complicated Flexible Vibration System Based on Power Flow Finite Element Method"(No.50805088) and Foundation of State Key Laboratory of Automobile Dynamic Simulation at Jilin University "Active control of the vibration and noise of vehicle cabs based on power flow finite element analysis"(No.20091110). It focused on the research on vibration of coupled-plate structures using Energy Finite Element Method. The major contents of this paper are listed as follows.The flexural and in-plane wave equations of thin plate, which can provide the theory basis for building the energy balance equations and energy transfer coefficients, have been deduced. And, the energy transfer coefficients of different coupled-plate structures with different incident angle have been derived. The results showed that there was waveform conversion at coupled lines. And the energy transfer coefficients changed with the incident angle. It obtained the coupled matrices of reinforced beam-plate coupled structures and L-shaped plates based on the energy transfer coefficients. The global matrix has been assembled in this paper. And the energy density of structures was calculated with the Matlab software.This Energy Finite Element Method was successfully applied to some practical engineering structures. Through numerical simulations, the energy density and the intensity fields of flexural and in-plane waves of the structures were obtained.更多还原