多悬臂梁–流体的模态耦合与拍振研究

Research on Modal Coupling and Slap Phenomenon of Multi-Cantilever Beam-Fluid Structure

摘要: 本文采用ANSYS软件对多悬臂梁–液体耦合系统进行了模态分析，得到了结构系统湿频率随液体宽度的变化规律，其结果与理论解答一致；研究了多悬臂梁–液体体系的拍振现象，在多梁–液体体系中，不仅存在梁与液体的相互作用，同时也存在梁与梁的相互作用，梁间相互作用随着梁间液体宽度的增加而减弱；系统拍振现象是由梁间相互作用产生的模态频率差导致，由于不同振型对不同梁位移函数贡献不同，不同梁的拍现象频率及振幅一般不同。

Abstract: In this paper, the modal analysis of multi-cantilever beam and fluid system is carried out by ANSYS code. The variations of wet frequencies of coupling system with the fluid width are obtained. The results agree well with the theoretical solutions. The beat vibration of multi-cantilever and fluid system is studied. In multi-cantilever beam and fluid system, not only there is interaction between beam and fluid, but also the interaction between the beams. The interaction effect between beams decreases with the increase of fluid width between beams. The difference of modal frequency caused by the interaction between beams results in beat vibration of multi-cantilever and fluid system. Because the different contributions of mode shapes are given to the displacement functions of different beams, the frequency and amplitude of beat vibration are generally different for the different beams.