Abstract The applicability of pressure-impulse theory is evaluated for predicting wave impact loading magnitudes for non-breaking standing wave impacts on vertical hydraulic structures with relatively short overhangs. To this end, tests were carried out on a schematized but realistic configuration with low steepness regular wave impacts on a straight overhang perpendicular to a vertical wall. This paper aims to fill the existing knowledge gap on this type of wave impact with reliable and simple expressions. Pressure-impulses and force-impulses are the wave impact loading magnitudes considered in this study, which are defined as the integral of the impulsive pressures/forces over time during a wave impact. These impulses can be used to determine the resulting stresses in a structure for sudden, impulsive loads. The proposed theoretical model is based on the pressure-impulse theory and validated with laboratory experiments. The laboratory tests are done with regular waves for relatively short overhangs, with ratios of wave length to overhang length between 12.1 and 43.6, and ratios of overhang height to overhang length of 3 and 6. Thus, the theory is verified for conditions where the wave impact takes place along the full length of the overhang. From the experimental results, a mean effective bounce-back factor β = 1.17 is obtained, accounting for the bounce-back effect of entrapped air and other secondary sources of discrepancies between theoretical and experimental results. The standard deviation of β for all the different tests is σ β = 0.11 . This method seems suitable for carrying out preliminary loading estimations, including the pressure-impulse profile at the wall and the total force-impulse at the wall. This study also shows that the force-impulse is a more stable magnitude compared with the force peaks, with about half the relative standard deviation. The impulses predicted by this model are recommended to be coupled with fluid-structure interaction models for analysing the response of the loaded structure.

中文翻译：

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短悬垂立式水工结构驻波冲击载荷压力脉冲理论验证

摘要 评估了压力脉冲理论在预测波浪冲击载荷大小方面的适用性，该波浪冲击载荷大小是对悬垂相对较短的垂直水工结构的不间断驻波冲击。为此，测试是在具有低陡度规则波冲击垂直于垂直墙壁的直悬垂的示意性但现实的配置上进行的。本文旨在用可靠和简单的表达方式填补有关此类波浪冲击的现有知识空白。压力脉冲和力脉冲是本研究中考虑的波浪冲击载荷大小，其定义为波浪冲击期间冲击压力/力随时间的积分。这些脉冲可用于确定结构中因突然的脉冲载荷而产生的应力。所提出的理论模型基于压力脉冲理论，并通过实验室实验进行了验证。实验室测试是使用相对较短悬垂的规则波浪完成的，波长与悬垂长度的比率在 12.1 和 43.6 之间，悬垂高度与悬垂长度的比率为 3 和 6。因此，该理论在波浪的条件下得到验证冲击沿悬垂的整个长度发生。根据实验结果，获得了平均有效反弹系数 β = 1.17，说明了夹带空气的反弹效应和理论与实验结果之间差异的其他二次来源。所有不同测试的 β 标准偏差为 σ β = 0.11 。这种方法似乎适合进行初步负荷估计，包括壁上的压力脉冲分布和壁上的​​总力脉冲。这项研究还表明，与力峰值相比，力脉冲的幅度更稳定，相对标准偏差约为一半。建议将此模型预测的脉冲与流固耦合模型结合起来，以分析受载结构的响应。