作为一种新型被动减振技术,颗粒阻尼已被应用于船舶、航空等领域。为进一步研究颗粒阻尼耗能机理,提高其减振性能,基于离散元(Discrete Element Method,DEM)-多体动力学(Multi Body Dynamic,MBD)耦合方法建立弹簧-颗粒阻尼减振系统模型...作为一种新型被动减振技术,颗粒阻尼已被应用于船舶、航空等领域。为进一步研究颗粒阻尼耗能机理,提高其减振性能,基于离散元(Discrete Element Method,DEM)-多体动力学(Multi Body Dynamic,MBD)耦合方法建立弹簧-颗粒阻尼减振系统模型,研究颗粒填充率及颗粒半径对系统减振效果的影响,并分析其耗能特性;通过试验验证DEM-MBD耦合仿真方法的准确性,等效阻尼比仿真值与试验值的平均误差为11.8%。研究结果表明:通过选择合适的填充比,可使弹簧-颗粒阻尼减振系统最大等效阻尼比比无颗粒时提高12.9倍。研究结果可为后续颗粒阻尼减振设计提供一定参考。展开更多
In this paper, the effect of green water impact on a flexible structure is studied based on three-step computational fluid dynamics(CFD)–boundary element method(BEM)–finite element method(FEM) approach. The impact d...In this paper, the effect of green water impact on a flexible structure is studied based on three-step computational fluid dynamics(CFD)–boundary element method(BEM)–finite element method(FEM) approach. The impact due to shipping of water on the deck of the vessel is computed using commercial CFD software and used as an external force in coupled BEM-FEM solver. Other hydrodynamic forces such as radiation, diffraction, and Froude-Krylov forces acting on the structure are evaluated using 3 D time domain panel method. To capture the structural responses such as bending moment and shear force, 1 D finite element method is developed. Moreover, a direct integration scheme based on the Newmark–Beta method is employed to get the structural velocity,displacement, etc., at each time step. To check the effect of the green water impact on the structure, a rectangular barge without forward speed is taken for the analysis. The influence is studied in terms of bending moment, shear force, etc. Results show that the effect of green water impact on the bow region can be severe in extreme seas and lead to various structural damages. Similarly,it is also verified that vessel motion affects green water loading significantly and therefore one must consider its effect while designing a vessel.展开更多
文摘作为一种新型被动减振技术,颗粒阻尼已被应用于船舶、航空等领域。为进一步研究颗粒阻尼耗能机理,提高其减振性能,基于离散元(Discrete Element Method,DEM)-多体动力学(Multi Body Dynamic,MBD)耦合方法建立弹簧-颗粒阻尼减振系统模型,研究颗粒填充率及颗粒半径对系统减振效果的影响,并分析其耗能特性;通过试验验证DEM-MBD耦合仿真方法的准确性,等效阻尼比仿真值与试验值的平均误差为11.8%。研究结果表明:通过选择合适的填充比,可使弹簧-颗粒阻尼减振系统最大等效阻尼比比无颗粒时提高12.9倍。研究结果可为后续颗粒阻尼减振设计提供一定参考。
基金supported by Naval Research Board,India under Project No.NRB-344/HYD/14-15
文摘In this paper, the effect of green water impact on a flexible structure is studied based on three-step computational fluid dynamics(CFD)–boundary element method(BEM)–finite element method(FEM) approach. The impact due to shipping of water on the deck of the vessel is computed using commercial CFD software and used as an external force in coupled BEM-FEM solver. Other hydrodynamic forces such as radiation, diffraction, and Froude-Krylov forces acting on the structure are evaluated using 3 D time domain panel method. To capture the structural responses such as bending moment and shear force, 1 D finite element method is developed. Moreover, a direct integration scheme based on the Newmark–Beta method is employed to get the structural velocity,displacement, etc., at each time step. To check the effect of the green water impact on the structure, a rectangular barge without forward speed is taken for the analysis. The influence is studied in terms of bending moment, shear force, etc. Results show that the effect of green water impact on the bow region can be severe in extreme seas and lead to various structural damages. Similarly,it is also verified that vessel motion affects green water loading significantly and therefore one must consider its effect while designing a vessel.
