As a typical fluid-structure coupling problem, structure impacting into water is widely used in the field of ship and ocean engineering, especially as a flat model of offshore platform. It has important engineering applicationback-ground and academic research value. In this paper, the ALE algorithm is used to simulate and analyze the two-dimensional elastic flat-bottomed structures under constant velocity impact. The Lagrange element and Euler element are used tocharac-terize the structure and fluid. The simulation of the fluid-solid coupling process is realized by the coupling algorithm. Thein-fluence of air cushion on the bottom pressure of the structure, the conditions of mass, stiffness and water velocity aredis-cussed. The results show that the pressure at the bottom edge of the flat bottom structure first reaches the peak value, and then the pressure peak appears in the direction of the width direction, and the motion after the constant velocity impact into the water is free vibration. The peak value of impact pressure increases with the increase of structure mass and stiffness, and the peak value of shock pressure has a linear relationship with velocity, increases with the increase of velocity, and the effect of the bottom angle on the peak value of impact pressure is significant. The above study provides an important basis for structural strength design in engineering application.%结构冲击入水作为一种典型的流固耦合问题广泛存在于船舶与海洋工程领域,特别是作为海洋平台简化模型的平底结构有着重要的工程应用背景和学术研究价值.本文采用ALE算法对二维弹性平底结构等速冲击入水过程进行数值模拟和分析,分别采用Lagrange单元和Euler单元来表征结构和流体,并通过耦合算法实现对流固耦合过程的模拟,分别讨论不同质量、刚度及入水速度情况下空气垫现象对结构底部压力的影响.计算结果表明,平底结构入水冲击过程中,底部边缘处压力最先达到峰值,随后沿宽度方向向中心依次出现压力峰值,且结构等速冲击入水后的运动为自由振动.冲击压力的峰值随结构质量及刚度的增大而增大,同时冲击压力峰值与速度呈线性关系,随速度的增大而增大,底部斜升角对冲击压力峰值的影响十分显著.通过上述研究为工程应用中的结构强度设计提供重要依据.
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