基于子结构技术的全船总体和局部振动研究

Global and Local Vibration Research Based on Substructure Synthesis Method

针对局部振动计算中难以确定局部构件的边界条件和全船振动计算成本过大的问题,引入子结构技术。阐述了子结构技术的基本理论,结合子结构和流固耦合技术,对一艘新型散货船进行了局部和全船振动分析预报。在预报过程中,运用流固耦合方法添加外部附连水和油水舱质量,用子结构界面减缩技术确定局部边界条件,进行局部模态分析,运用计算效率成倍提高的部件模态综合法进行总振动预报。最终,提出了横撑及其船体加强的优化方案。该方案能改良主机和船体结构的振动性能,并满足各自的标准要求。

Confirming the boundary condition in the local vibration analysis and saving computation cost in the global vibration analysis are two difficult issues regarding ship vibration analysis. The substructure synthesis technology could contribute the great function to the either local or global vibration analysis. The basic theory of substructure synthesis method was depicted in this paper. Based on substructure synthesis and fluid-solid coupled method ,a study of global and local vibration of a new type bulk carrier was performed. The research simulated the added mass and fluid cargo by using fluid structure interaction(FSI) method;adopted component boundary condensed method to process component mode analysis;and carried on component modal synthesis,which dramatically increased the computation efficiency,to analyze the global vibration response. Based on the calculation,an optimistic scheme of adding top bracing was proposed. The performance of main engine and ship structure satisfied and met their own standards well respectively after the proposal had been performed. The paper demonstrated the substructure synthesis technology could have great engineering efforts to both local and global vibration analysis.