Constrained antiresonance frequencies-based model updating method for better matching of FRFs
Constrained antiresonance frequencies-based model updating method for better matching of FRFs
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DOI：
10.1080/17415977.2013.840299
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发表时间：
2014-05
影响因子：
1.3
通讯作者：
Vikas Arora
中科院分区：
文献类型：
--
作者：
Vikas Arora
大多数有限元模型修正方法使用共振频率和振型来修正质量和刚度矩阵。这些模型修正方法不是很准确，因为不能准确地估计Modeshape。然而，根据测量的频率响应函数(FRF)可以准确地估计反共振频率。为了更好地匹配频响函数，本文提出了一种基于反共振的模型修正方法，对预测频响函数的误差施加约束。在该方法中，质量和刚度矩阵根据反共振频率和共振频率进行更新。在更新后的模型中，采用了等权系数，使得共振频率和反共振频率的贡献相等。通过两个算例验证了所提出的有限元修正方法的有效性。首先给出了简单固-固梁结构的算例，然后对类似于钻机骨架的F型结构进行了算例分析。将该方法与标准的直接模型修正方法进行了比较。修正结果表明，基于反共振的模型修正方法可以得到精确的系统模型。通过将从更新模型得到的频响函数与实验频响函数进行匹配来说明这一点。
Most of the finite element model updating methods use resonance frequencies and modeshapes for updating mass and stiffness matrices. These model updating methods are not very accurate as modeshapes cannot be estimated accurately. Whereas, antiresonance frequencies can be estimated accurately from measured frequency response functions (FRFs). In this paper, a new antiresonance-based model updating method is proposed for better matching of FRF by imposing constraint on error in predicted FRF. In the proposed method, mass and stiffness matrices are updated in the light of antiresonance frequencies along with resonance frequencies. Equal weight factors are applied so that there is an equal contribution of resonance and antiresonance frequencies in the updated model. The effectiveness of the proposed finite element updating method is demonstrated by two experimental examples. Firstly, case study of simple fixed–fixed beam structure is presented which is followed by a case study of F-shaped structure, which resembles the skeleton of drilling machine. The proposed method is compared with a standard direct model updating method. The updated results have shown that antiresonance-based model updating method can be used to derive accurate model of the system. This is illustrated by matching of the FRFs obtained from the updated model with that of experimental FRF.