Study of the effect of specimen size and frequency on the structural damping property of beam
Study of the effect of specimen size and frequency on the structural damping property of beam
复制标题
试件尺寸和频率对梁结构阻尼性能影响的研究
DOI：
10.1299/mej.16-00446
复制
发表时间：
2016
影响因子：
4.4
通讯作者：
T. Ise
中科院分区：
文献类型：
--
作者：
S. Kawamura;M. Kita;M. Matsubara;T. Ise
据说，表征结构阻尼的参数，即，损耗因子与试样的材料相同，但实际上，阻尼特性有时会受到试样尺寸或频率的影响。本文研究了试件尺寸和频率对结构阻尼特性的影响。首先，我们提出了一种简单的方法识别模态参数时，阻尼特性建模为结构阻尼。其次，利用该方法对简支薄钢梁的模态参数进行了识别。得到了等厚不等长试件和等长不等厚试件的固有频率与模态阻尼比的关系。然后，我们确定表征阻尼特性的参数。结果表明，模态阻尼比在低频范围内较大，而在高频范围内较小且恒定，即阻尼特性与频率有关，不能仅用损耗因子来表示阻尼特性。对于相同厚度的试件，其固有频率与模态阻尼比之间的关系是一致的，而对于不同厚度的试件，其固有频率与模态阻尼比之间的关系则不同，即阻尼特性与厚度有关。因此，在实际设计过程中，在预测阻尼性能时，应考虑试件尺寸和频率的影响。
It is said that the parameters that characterize structural damping, i.e., the loss factor, are identical to the material of the specimen, but in actuality, the damping property is sometimes affected by specimen size or the frequency. In this paper, we investigated the effect of specimen size and frequency on the structural damping property. First, we showed a simple identification method for modal parameters when the damping property is modeled as the structural damping. Next, we identify the modal parameters of the freely supported thin steel beam using the method. We obtain the relationship between the natural frequency and modal damping ratio for specimen with the same thickness but different length, and for specimen with the same length but different thickness. Then we identify the parameters that characterize the damping property. The results showed that the modal damping ratio was high in the lower frequency ranges, though light and constant in the higher frequency ranges, that is, the damping property depends on the frequency, so that the damping property could not be expressed only by the loss factor. And the relationship between the natural frequency and the modal damping ratio was identical for specimen with same thickness, though it is not for specimen with the different thickness, that is, the damping property depends on the thickness. We conclude that the effect of specimen size and frequency should be considered when predicting damping property in actual design processes.