建立了水中悬浮隧道在冲击载荷作用下的简化计算模型。用等效质量法将圆柱壳分布质量折算成冲击点处的集中质量,模型中考虑流体附加质量和系统阻尼的影响。根据碰撞过程中的动量守恒、变形过程中的能量守恒以及结构的位移与内力关系,得到问题的解析解。为验证解析解,在ANSYS/LS-DYNA中建立了动态冲击有限元分析模型。通过算例分别考察了在忽略和考虑流体附加质量两种情况下,冲击点位置和冲击速度对冲击点处最大径向位移的影响,将解析解与数值解进行对比,结果吻合较好。然后采用数值模拟方法得到了系统阻尼对计算结果的影响规律。数值模拟过程中还可以得到冲击点处的最大Mises应力。
A calculation model for submerged floating ttmnel (SFT) subjected to impact loading is developed, The distributed mass of the cylindrical shell is converted into concentrated mass at the impact position. Based on energy conservation during deformation process, momentum conservation during impact and the relationship between displacements and internal forces, the analytical solution is obtained, which considers the effects of added water mass and system damping. In order to verify the analytical result, a f'mite element model of impact is established using the ANSYS/LS-DYNA code. A simulation example is given to examine the effects of impact position and impact velocity on the maximum radial displacement at impact position. Both cases with and without added water mass are considered. The analytical solution and numerical simulation are compared, showing that they are in good agreement. The effects of system damping on the results are obtained by further numerical simulation. During the numerical simulation, the maximum von Mises stress at impact position can also be obtained.