平板结构广泛应用于海底生产设施，安装作业中的入水砰击动力学对结构安全具有重要影响，特别是入水角度的影响亟待深入研究。本文基于平滑质点流体动力学（SPH）方法结合自适应粒子细化技术，建立了平板入水砰击三维数值模型，分析了入水角度对平板入水砰击动力学的影响。结果表明，入水角度显著改变平板与水体的相互作用机制。垂直入水（0°入水角度）时，水体受阻滞效应影响，能量更为集中，导致剧烈砰击；倾斜入水时，水体侧向逃逸效应增强，使入水砰击流场转变为非对称结构并显著降低载荷。砰击载荷与入水角度呈负相关性，5°入水时不同测点的压强峰值存在时序差异且仅为0°入水时的70%，5°入水时的砰击力仅为0°时的20%。本文系统研究了入水角度对平板入水砰击动力学的影响规律，可为水下结构物的设计与安装提供理论指导。

Flat plate structures are widely used in subsea equipment， and the water-entry slamming dynamics during installation operations have a significant influence on structural safety. In particular， the effect of entry angle has not yet been sufficiently investigated. In this study， a three-dimensional numerical model for flat plate water entry slamming was established based on the smoothed-particle hydrodynamics （SPH） method combined with an adaptive particle refinement technique. The influence of entry angle on the slamming dynamics of a flat plate during water entry was systematically analyzed. The results indicate that entry angle significantly alters the interaction mechanism between the flat plate and water. During vertical water entry （0° entry angle）， the blockage effect of water leads to a stronger concentration of energy， resulting in more violent slamming. In contrast， during oblique water entry， the lateral escape effect of water is enhanced， causing the slamming flow field to transform into an asymmetric structure and significantly reducing slamming loads. The slamming load exhibits a negative correlation with entry angle. At an entry angle of 5°，the pressure peaks at different measurement points show noticeable temporal discrepancies and are only about 70% of those under vertical entry conditions. Moreover， the slamming force at 5° is only approximately 20% of that at 0°.This study systematically investigated the influence of entry angle on slamming dynamics of flat plate water entry and can provide theoretical guidance for design and installation of subsea structures.