子结构方法在圆柱壳体振动特性分析中的应用研究

Substructure Synthesis Method for Vibration Characteristics Analysis of Cylindrical Shell

针对大型复杂结构振动特性的预测问题,发展了一种子结构方法,并应用于圆柱壳模型的振动特性研究。圆柱壳模型长4.2m,直径0.4m,由5部分组成,并且在第4和第5部分内有一个轴系结构。用子结构方法研究其振动特性时,模型被分为3个子结构,子结构间通过螺栓进行连接。因此,首先介绍了子结构方法及连接处理方式的理论基础,然后通过实验验证了发展方法的正确性,并着重分析了子结构模态综合阶数和连接处理方式对整体结构预测结果的影响规律,最后对比分析了子结构方法与传统有限元法对计算量和内存量的要求。结果表明:发展的子结构方法具有较高的精度,可应用于求解船舶等大型复杂结构的振动特性。

The substructure synthesis method was developed and applied to predict the structure vibration characteristics of a cylindrical shell model with length and diameter of 4.2m and 0.4m respectively. The shell model consists of five parts and a shafting passing through the fourth and the fifth parts. When computing, the model was divided into three substructures connected by bolts. Theories about the substructure synthesis method and the connection modeling technique were introduced at first. Then the accuracy of the developed method was verified by comparing the predicted results with the experimental results of the structure modes. Several factors, such as modal reduction and interface conditions, were studied about their effects on the accuracy of the predictions. Computational time and memory usage of the substructure synthesis method were compared with those of the traditional FEM. The comparison shows the efficiency of the substructure synthesis method. The results show that the developed substructure synthesis method is an effective method for predicting vibration characteristics of large and complex structures such as ships.