Asymptotic Modal Analysis of Structural-Acoustic Systems

用统计方法处理结构系统的思想 为了了解全球应对 当多个模式被激发时的结构。 统计 能量分析（SEA）方法已被广泛用于 确定对宽带激励的动态响应 线性一维和二维结构以及三维 内部声场 本项目将该方法扩展到（1） 三维固体，（2）外部（无界）声学 场，（3）小规模，局部结构非线性和（4） 耦合系统的SEA。 在第一阶段，SEA结果将 最初是在三维的框架内得出的， 线性粘弹性固体，然后扩展到粘弹性 与金属结构基础相结合的固体。 同相 第二，首席研究员将使用他以前开发的 确定双声源远场的SEA方法 维度结构以多种模式响应。 意图 这里是比较这个概念与完整的经典模式 以确定SEA方法的适用范围。 在 第三阶段，经典的分量模态综合方法是 结合战略环境评估概念，以确定全球影响 当许多模式被激发时，结构上的非线性。 在第四阶段，目的是完善目前的方法， 可用于确定耦合系统之间的损耗因子。 这项工作的影响将是能够更好地描述 复杂动力系统的动力学， 多个自由度。

The idea of treating a structural system in a statistical manner has been developed in order to understand the global response of the structure when many modes are excited. The statistical energy analysis (SEA) approach has been widely used for determining the dynamic response to broad band excitation of linear one and two dimensional structures and three dimensional internal acoustic fields. This project extends the method to (1) three dimensional solids, (2) external (unbounded) acoustic fields, (3) small scale, local structural nonlinearities and (4) SEA for coupled systems. In the first phase, the SEA result will initially be derived within the framework of a three dimensional, linear viscoelastic solid and then extended to a viscoelastic solid combined with a metallic structural foundation. In phase two, the Principal Investigator will use his previously developed SEA method for ascertaining the acoustic far field when a two dimensional structure is responding in many modes. The intent here is to compare this concept with the full classical modal result to determine the SEA method's range of applicability. In phase three, the classical component mode synthesis method is combined with SEA concepts to ascertain the global effects of nonlinearities on a structure when many modes have been excited. In phase four, the intent is to refine the methods currently available for determining loss factors between coupled systems. The impact of this work will be to permit a better description of the dynamics of complex dynamical systems which are responding in many degrees of freedom.