墩柱结构波浪冲击压力分布特征及应力谱分析

Analysis of wave impact pressure distribution and stress spectrum in the splash zone of offshore pier columns

波浪的低频往复冲击作用加速了墩柱结构物浪溅区涂层的剥蚀,使其暴露于强腐蚀性的海洋环境中,进而导致结构物腐蚀破坏和提前失效,而波浪冲击力是造成涂层力学剥蚀的主要因素之一。该文基于有限差分求解,应用FLOW-3D建立波浪水槽三维数值模型,通过分析近岸墩柱结构物表面波浪冲击力分布特征和冲击过程的历时曲线,探讨不同波浪要素下波浪冲击力的变化规律,并建立了最大点压力处的波浪冲击力应力谱。结果表明:同一水平面,结构水平方向不同位置处(θ=0°、45°、90°、135°、180°)的点压力大小顺序为:Pθ=0°>Pθ=45°>Pθ=180°>Pθ=135°>Pθ=90°;在竖直方向上,静水面处的点压力最大,各高程的点压力值呈现与静水面距离的增加而线性减小的规律。从波浪冲击力应力谱中可以看出:在其他条件相同情况下,应力谱不受水深和周期的影响,但变化周期与波浪周期相同,而波高对应力谱的影响较大,呈正线性关系。

The low-frequency reciprocating impact of waves accelerates the erosion of the coating in the splash zone of the pier column, which exposes it to a highly corrosive marine environment, which leads to corrosion damage and early failure of the structure. Wave impact force is one of the main factors causing coating mechanical ablation. Based on the finite difference solution, FLOW-3 D is used to establish a three-dimensional numerical model of wave flume. By analyzing the distribution characteristics of wave impact force on the surface of the near-shore pier column structure and the duration of the impact process Curve, the change law of wave impact force under different wave elements is discussed, and the stress spectrum of wave impact force at the maximum point pressure is established.. The results show that the point pressure in the same horizontal plane at different positions in the horizontal direction of the structure(θ =0°、45°、90°、135°、180°) is: Pθ =0°>Pθ =45°>Pθ =180°>Pθ =135°>Pθ =90°;in the vertical direction, the point pressure at the static water surface is the largest, and the point pressure values at each elevation appear that the values decrease linearly with the from water surface distance increasing. It can be seen from the wave impact stress spectrum: under the same conditions, the stress spectrum is not affected by water depth and period, but the change period is the same as the wave period, and the wave height has a greater influence on the stress spectrum, showing a positive linear relationship.