基于SPH-FE方法的波浪中结构物动力特性模拟研究

SPH-FE method-based numerical simulation on dynamic characteristics of structure under waves

海工结构物在波浪荷载作用下产生动力响应,本文基于光滑粒子流体动力学-有限元(SPH-FE)耦合方法对结构物受孤立波冲击过程中表面压力分布和动力响应特性进行研究.通过溃坝模型模拟了水柱倒塌冲击结构物的过程,分析SPH模型中粒子间距对数值结果的影响,并通过与文献结果对比验证了本文数值方法的可行性.在此基础上研究水柱高度、水柱与结构物间距及结构物刚度对波浪到达时间、结构动力响应和波浪冲击荷载特性的影响.研究结果表明:在本文计算条件下,波浪到达结构物的时间与溃坝初始水柱高度关系不明显,但随水柱与结构物间距的增大而线性增加;结构物顶端位移响应幅值随水柱高度、水柱与结构物间距及结构物刚度的变化较明显;结构物所受波浪冲击荷载与水动力作用呈正相关关系;当水动力作用相同,结构刚度增大时,结构物底端所受波浪力会增大.

Coastal structure is prone to generate dynamic response under large wave load. In this paper, SPH FE coupling method is used to study the structure＇s surface pressure distribution and its dynamic response under the impact of solitary waves. The dam break model is established to simulate the impact process that the water column collapse imposes on the structure. A key impact in SPH simulation, particle spacing, is proposed, leading to perfect numerical results, and the model is validated through comparison with the existing methods. Multifactor influences on the wave arrival time, the structural dynamic response and the variation of wave load charac teristics are studied, including the water column height, the distance between water column and structure pacing, as well as the structure stiffness. The results show that the wave arrival time increase linearly with the increase of water column structure distance, while it is irrelevant to the initial water column height. The peak displacement at the top of the structure varies observablywhen the water column height, water column structure distance and structure stiffness change. Under the same hydrodynamic force, increasing structure stiffness will result in the increase of the structure impact load and the increase of water pressure at the bottom of the structure.