船体基座粘弹性复合阻尼减振性能试验研究

  目的  为了解决现有的阻尼材料粘贴质量对于声学检验方法数据敏感度低的问题，  方法  提出基于频响函数的频点振级落差概念。以船舶通用基座实验台架为待测结构，利用锤击法获取阻尼材料粘贴面积改变前、后的实验数据，采用阻尼因子、合成频响函数级、频点振级落差和典型测点间的频谱，对数据进行处理和对比分析，得到不同方法对粘贴质量异常问题的数据敏感度，以及识别异常问题区域的准确性。
  结果  研究表明，与其他3种方法相比，将频点振级落差概念应用于阻尼材料粘贴质量问题识别时，在完全贴合状态下，2次测量结果的偏差在1 dB以下；改变粘贴面积后，单频点振级落差和频点振级落差总级均明显高于2 dB，曲线偏移明显。  结论  频点振级落差分析方法具有数据敏感度高、数据量小、粘贴质量异常问题区域识别准确等优点，可推广应用。

Experimental research on vibration damping characteristics of hull base structure with visco-elastic composite material

  Objectives  In order to improve the data sensitivity of current acoustic test methods on the construction quality of damping material,  Methods  the vibration level difference of single frequency points based on the Frequency Response Function(FRF)is proposed. Aiming at a general ship-based test bench, the hammering method is utilized to obtain testing data of the damping material before and after changing the sticking area. The damping factor, synthetic FRF level, vibration level difference of single frequency points and frequency spectrum of the typical measuring points are then used to carry out data processing and comparison analysis.
The data sensitivity of abnormal sticking quality and the accuracy of identifying abnormal areas are then obtained.  Results  When using the vibration level difference of single frequency points for the identification of abnormal sticking quality in damping material, the data deviation is less than 1 dB when the damping material makes complete contact, and more than 2 dB when the sticking quality is changed as the frequency point.  Conclusions  The method of using the vibration level difference of single frequency points is characterized by high data sensitivity, low data amount and accurate identification of abnormal areas, making it worthy of application.