Energy flow models from finite element analysis
Energy flow models from finite element analysis
复制标题
DOI：
10.1006/jsvi.1999.2812
复制
发表时间：
2000-06-08
影响因子：
4.7
通讯作者：
Shorter, PJ
中科院分区：
文献类型：
--
作者：
Mace, BR;Shorter, PJ
描述了计算有效的方法，通过这些方法，可以对系统的有限元分析结果进行后处理，以形成能量流模型、屈服时间以及可能的频率平均子系统能量以及输入和耗散功率。对于空间分布的或宽带的激励(例如，屋顶上的雨)，或者如果需要频率平均响应，该方法特别有效。首先，提出了一种基于整体有限元分析的方法。这涉及到全局模式分解和随后的数值计算的重新排序。激励的分布以及系统的质量和刚度的特性决定了分系统的力分布、质量分布和刚度分布矩阵。响应由涉及一对全局模式相互作用的项和给出，每对模式的贡献取决于分布矩阵的适当元素。频率平均是通过分离产生的频率相关项并积分来执行的。在大多数实际情况下，这种集成可以通过分析来完成。接下来，描述涉及部件模式综合的替代方法。在这种情况下，使用固定界面方法对每个子系统进行单独的有限元分析。然后将它们组合在一起执行全局模态分析，模型的阶数大大降低。然后以相同的方式对结果进行后处理。最后，给出了一个由三个耦合的棱镜组成的系统作为数值例子。(C)2000年学术出版社。
Computationally efficient methods are described by which the results of a finite element analysis of a system may be post-processed to form energy flow models, yielding time and, perhaps, frequency average subsystem energies as well as input and dissipated powers. The methods are particularly efficient for excitation which is spatially distributed or broadband (e.g., rain-on-the-roof) or if the frequency average response is required. First a method based on a global finite element analysis is presented. This involves a global modal decomposition and a reordering of the subsequent numerical calculations. The properties of the distribution of the excitation and the system's mass and stiffness lead to subsystem force distribution, mass distribution and stiffness distribution matrices. The response is given by a sum of terms involving the interaction of a pair of global modes, the contribution of each pair depending on the appropriate elements of the distribution matrices. Frequency averaging is performed by separating the resulting frequency-dependent terms and integrating. In most practical cases this integration can be done analytically. Next an alternative method involving component mode synthesis is described. In this, individual finite element analyses are performed for each subsystem using, here, the fixed interface method. These are then assembled to perform a global modal analysis, with the order of the model being much reduced. The consequent results are then post-processed in the same way. Finally, a system comprising three coupled prates is presented as a numerical example. (C) 2000 Academic Press.