应用空间有限元模型进行船舶总振动特性的研究

本文以17500吨货船“海建”号为实例研究应用空间有限元模型计算船舶总振动的方法。对于实际船舶结构中的板,提出用平面应力元简化,以减少计算自由度数,由此产生的问题采用节点主从关系的方法解决。在编制的计算程序中,根据质量矩阵高度稀疏的特点,采用了稀疏存储技术,从而使船舶整体空间模型的振动分析能在国产中小型机器上实现。实例计算结果和测量结果的比较表明,这种计算模型合理、可靠。本文还对船舶总振动计算的梁模型、平面有限元模型、空间有限元模型作了比较和讨论。

A STUDY ON SHIP HULL VIBRATION USING THREE-DIMENTIONAL FINITE ELEMENT MODEL

This paper discusses the application of three-dimensional finite element model for the calculation of ship hull vibration. The plates of ship structures are regarded as plane stress elements to reduce the degrees of freedom in calculation, and the problem resulting from such treatment are solved by employing the master-slave node relation method. Generally, most of the elements in the mass matrix are concentrated in the diagonal of the matrix, and employ the special storage method in the program to save the storage of the computer. Using the multi-element structural dynamic analysis program DDJ(DL), we have calculated the hull vibration of a carrier (17500 dwt)on the Model TQ-16 Computer made in PRC. Compared with actual measurements, the results of the calculation show that this three-dimensional finite element model is appropriate for analyzing the dynamic characteristics of ship. Finally, the three models (beam model, two-dimensional finite element model and three-dimensional finite element model)for ship hull structures are compared.