计及流体效应的三体船流固耦合自振特性

Research on fluid-structure coupled vibration characteristic of trimaran subjected to hydrodynamic effect

采用有限元法和边界元法比较分析三体船结构的流固耦合振动问题,探讨深V型、浅吃水侧体的附连水质量对三体船总振动特性的影响。通过对全船三维结构有限元模型进行纯数值计算,获得三体船结构在无限域流场中的湿模态特性。研究发现,计及流体效应后的三体船自振频率比干模态频率明显降低,首部水平振动与尾部扭转振动的耦合振动在高阶模态中较为突出,侧体的附连水质量对三体船垂向和水平振动影响较小。

The finite element method and the boundary element method were presented to analyze the fluid-structure coupled vibration problem of trimaran,and then the impact of side hull＇s additional water mass on the trimaran overall vibration characteristic was discussed. The natural frequencies and mode shapes of trimaran structure in infinity water were obtained by numerical calculation based on the global finite element. The results show that trimaran＇s natural vibration frequency decreased significantly after taking fluid effect into account. Bow horizontal vibration and stern torsional vibration are coupled distinctly in the high order modes,side hull＇ s additional water mass has little effect on the trimaran＇s vertical vibration and horizontal vibration.