基于模态柔度的有限元模型修正方法

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振动与冲击 ›› 2013, Vol. 32 ›› Issue (13) : 106-111.

论文

基于模态柔度的有限元模型修正方法

魏锦辉1，2，任伟新1，万华平1

作者信息 +

Method of finite element model updating based on modal flexibility

WEI Jin-hui1, 2, REN Wei-xin1, WAN Hua-ping1

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文章历史 +

摘要

以各阶模态柔度矩阵中各元素相对变化作为指标，提出了基于模态柔度灵敏度解析表达式的有限元模型修正方法，推导了模态柔度灵敏度解析表达式，结构严谨，编程方便。以一平面简支梁为例，考虑运用不同的模态阶数、测点自由度及测试误差，利用Tikhonov正则化方法进行模型修正，通过多次模拟计算，分析了相关因素对模型修正结果的影响。实例计算表明，当噪声较小时，修正效果很好，但随着测试噪声水平的增加，修正结果稳定性变得相对较差；利用较高阶模态修正结果比利用较低阶模态修正后结果要好；同时测试自由度不完整性也是模型修正结果的不利因素。

Abstract

Based on closed form of modal flexibility sensitivity, a modal flexibility-based finite element (FE) model updating method taking element relative change of modal flexibility matrix as index is proposed in this paper. The analytical closed-form of modal flexibility sensitivity with simple, compact, and convenient programming formula is derived. The FE model of a numerical simple supported plane beam model was updated via Tikhonov regularization method, and the effects of different modal orders, test degree of freedom and test error were studied. Numerical results show that, reliable updating results can be obtained with less test error, but it becomes unstable as increasing test error. While the order number is relative high, updating results are reliable and less affected by test. Besides, incompleteness of test degree of freedom affects the updating results a lot.

导出引用

魏锦辉;任伟新;万华平. 基于模态柔度的有限元模型修正方法[J]. 振动与冲击, 2013, 32(13): 106-111

WEI Jin-hui;;REN Wei-xin;WAN Hua-ping. Method of finite element model updating based on modal flexibility[J]. Journal of Vibration and Shock, 2013, 32(13): 106-111