船舶双层底框架的模态分析

采用有限元方法,对主机机舱双层底框架进行模态分析,分析板厚和肋对结构振动模态的影响.结果表明,增加船舱板厚度会使结构刚度和固有频率上升,但与单板所呈现的同阶频率等幅增大的规律不同;肋对结构振动模态的影响比较复杂.分析指出工程中更应注意肋的选取.

Modal analysis of the double bottom frame of ships

The modal of the double bottom of the main engine room is analyzed using FEM, and the effects of the thickness of plates and added ribs on the modal are also analyzed. The results show that the increasing of the thickness of plates lead to the increasing of rigidity and natural frequency, which is different from the law of single plate -frequency of same step increases with the same value, and the added ribs make the natural modal vary largely. The analysis points out that the selection of ribs should be noticed during the project.