频响函数综合法预测结构在水下的动特性

Investigation of Dynamic Characteristics of Structure under Water

通过对一个结构模型在空气中和水下的动特性的研究，探讨了由结构在空气中的模态参数和水的附加质量预测结构在水下的模态参数的频响函数综合法，用以替代实体结构在水下的动特性试验。应用这种方法预测得到了结构在水下的模态参数并与结构的湿模态试验结果进行了对比。研究结果表明，对于所研究的梁形结构，不考虑水的阻尼，将水对结构的影响考虑成为附加质量。

Based on the research of the dynamic characteristics (DC) of an underwater structur's scale model, this paper develops a FRF synthesis method for estimating the modal parameters of structure under water by both the DC of structure in air and the added mass of water. This method may replace the modal test for the structure under water. The modal parameters of the structure under water are obtained by this method, and are compared to the results of its modal test under water. The results indicate that to the structure as mentioned in this paper, it is feasible to consider effects of water on the structure with the added mass, and this method is available to predict the DC of the structure under water.