Analysis of the flexural vibration of a thin-plate box using a combination of finite element analysis and analytical impedances
Analysis of the flexural vibration of a thin-plate box using a combination of finite element analysis and analytical impedances
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DOI：
10.1006/jsvi.2001.3847
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发表时间：
2002-01-17
影响因子：
4.7
通讯作者：
Pinnington, RJ
中科院分区：
文献类型：
--
作者：
Grice, RM;Pinnington, RJ
许多实际的薄板结构，例如现代的汽车车身，本质上是由许多薄板在边缘连接而成的。这些板是如此之薄，以至于它们总是用它们巨大的面内刚度来支撑结构和机械的重量。因此，从安装在这些刚性点上的源注入到结构中的振动功率由板中的高阻抗长波平面波控制。当长平面波在结构周围传播时，它们撞击在相邻板上产生短波长的弯曲波的众多结构节点上。这些弯曲波的阻抗比面内波低得多。因此，薄板结构在其刚性点处的振动发展为长平面波和短弯曲波的混合振动。在同一作者之前的一篇论文中，采用了一种仅考虑长平面波的数值高效有限元分析来预测六面薄板盒在刚性点处的强迫响应。本文采用有限元分析，并借鉴同一作者在另外两篇论文中提出的理论，将分析阻抗与有限元分析耦合，以表示结构节点处产生的短弯曲波。确定了定义这些分析阻抗所需的参数。阻抗的振动被用来计算箱边的均方弯曲振动的估计，与实验室测量值比较适度。该方法在预测所谓的“中频”区域的薄板结构振动方面应该有优点，在中频区域，长波的模态密度太低，不能可靠地应用统计能量分析，而短弯曲波的模态密度太高，不能；允许有效的有限元分析。(C) 2002年学术出版社。
Many practical built-up thin-plate structures, e.g., a modern car body, are essentially assemblies of numerous thin plates joined at their edges. The plates are so thin that they invariably support the weight of the structure and machinery using their substantial in-plane stiffness. Consequently, vibrational power injected into the structure from sources mounted at these stiff points is controlled by high impedance long-wavelength in-plane waves in the plates. As the long in-plane waves propagate around the structure, they impinge upon the numerous structural joints at which short-wavelength flexural waves are generated in adjoining plates. These flexural waves have much lower impedance than the in-plane waves. Hence, the vibration of thin-plate structures excited at their stiff points develops into a mixture of long in-plane waves and short flexural waves. In a previous paper by the same authors, a numerically efficient finite element analysis which accommodated only the long in-plane waves was used to predict the forced response of a six-sided thin-plate box at the stiff points. This paper takes that finite element analysis and, drawing on theory developed in two additional papers by the same authors, couples analytical impedances to it in order to represent the short flexural waves generated at the structural joints. The parameters needed to define these analytical impedances are identified. The vibration of the impedances are used to calculate estimates of the mean-square flexural vibration of the box sides which compare modestly with laboratory measurements. The method should have merit in predicting the vibration of built-up thin-plate structures in the so-called "mid-frequency" region where the modal density of the long waves is too low to allow confident application of statistical energy analysis, yet the modal density of the short flexural waves is too high to ;allow efficient finite element analysis. (C) 2002 Academic Press.