An experimental exploration of the properties of random frequency response functions
An experimental exploration of the properties of random frequency response functions
复制标题
随机频率响应函数特性的实验探索
DOI：
10.1016/j.jsv.2020.115773
复制
发表时间：
2021
影响因子：
4.7
通讯作者：
Clot A
中科院分区：
文献类型：
--
作者：
Clot A
在宽带频率范围内对复杂结构进行振动-声学分析是一个极具挑战性的问题，通常需要使用确定-统计混合方法。由于制造缺陷，名义上相同的系统集合的频率响应函数(FRF)可以被认为是随机的。然而，这些频响函数具有可以潜在地用于振声模型的统计特性。这项工作通过使用从名义上相同的结构的系综测量的FRF来探索这些基本性质中的一些，这些结构是通过使用点质量随机化薄矩形板获得的。首先证明了测得的FRF系综满足解析性-遍历性条件，并从实验上验证了这一最新证明的基本性质。然后，利用系综来探索是否可以通过实验获得确定-统计混合公式中的一个关键参数--直接场动态刚度。将结果与使用数值技术计算的结果进行了比较，表明在可以测量系统集合的情况下，测量数据可能是合适的替代方案。最后，对于实验随机化特别具有挑战性的情况，提出了一种基于虚拟点质量而不是物理点质量的替代方法。然而，人们已经发现，该方法可能对测量不精确度非常敏感，特别是当应用于轻阻尼结构时。结果表明，随机因果频响函数的统计特性不仅本身很有趣，而且可以增强和扩展振动-声学预测模型。
The vibro-acoustic analysis of complex structures over a broadband frequency range is an extremely challenging problem that may often require the use of a hybrid deterministic-statistical approach. Due to manufacturing imperfections, the frequency response functions (FRFs) of an ensemble of nominally identical systems can be considered to be random. These FRFs, however, have statistical properties that can be potentially used in vibro-acoustic models. This work explores some of these fundamental properties by using measured FRFs from an ensemble of nominally identical structures, obtained by randomising a thin rectangular plate using point masses. It is first shown that the measured ensemble of FRFs satisfies the analyticity-ergodicity condition, experimentally verifying this recently demonstrated fundamental property. Then, the ensemble is used to explore whether the direct field dynamic stiffness, a key parameter in a well-established hybrid deterministic-statistical formulation, can be obtained experimentally. The results are compared against those computed using numerical techniques, showing that measured data may be a suitable alternative provided that an ensemble of systems can be measured. Finally, an alternative method, based on the use of virtual point masses, opposed to physical ones, is proposed for those cases where experimental randomisation is particularly challenging. It has been found, however, that the method may be extremely sensitive to measurement imprecisions, specially when applied to lightly damped structures. It is concluded that the statistical properties of random causal FRFs are not only interesting in themselves, but can enhance and extend vibro-acoustic prediction models.
登录
查看更多内容
DOI：
--
发表时间：
1985
期刊：
影响因子：
--
作者：
P. A. Mello;P. Pereyra;T. Seligman
通讯作者：
T. Seligman
弹性动力学中的谱统计
影响因子：
2.4
作者：
R. Weaver
通讯作者：
R. Weaver
在被动位置重建格林函数的“往返”理论。
DOI：
10.1121/1.4821210
发表时间：
2013
期刊：
The Journal of the Acoustical Society of America
影响因子：
--
作者：
A. Moorhouse;A. Elliott
通讯作者：
A. Elliott
影响因子：
2.4
作者：
R. Lyon
通讯作者：
R. Lyon
混合 FE-SEA 实验模型的开发
影响因子：
4.7
作者：
Clot A
通讯作者：
Clot A