Abstract This study investigates the repeatability of ice-tank tests with broken ice. Ice-tank test campaigns normally do not perform multiple repetitions of tests with the same initial conditions. Therefore, the repeatability of ice-tank tests with broken ice is not well understood. Data from two test campaigns are analysed. The first test campaign studied the interaction between a 4-legged structure with a vertical waterline and several broken and intact level ice conditions. In the second test campaign, a ship hull geometry was tested. We analyse selected test cases from each test campaign. The ice-tank tests are reproduced using a 3-D discrete element method (DEM) model. Each analysed test case is simulated 20 times. The only difference between each simulation is the initial position of the ice floes. The numerical simulation results show that changes in the initial floe positions can cause large changes in the statistical properties of the ice load. Often, a single random interaction event can be identified that is responsible for the change in the results. Such interaction events can cause additional floe accumulation ahead of the structure, thereby influencing the load statistics for a large portion of the interaction length. The observed events occur both in the numerical simulations and in the physical ice-tank tests. This result indicates that ice-tank tests with broken ice have a poor repeatability; a change in an uncontrolled condition, such as the exact initial floe positions, can lead to a large variation in the experimental results.

中文翻译：

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碎冰冰罐测试的可重复性

摘要 本研究调查了冰罐碎冰试验的可重复性。冰罐测试活动通常不会在相同的初始条件下执行多次重复的测试。因此，冰罐碎冰测试的可重复性尚不清楚。分析了来自两个测试活动的数据。第一次测试活动研究了具有垂直吃水线的 4 条腿结构与几个破损和完整水平冰条件之间的相互作用。在第二次测试活动中，对船体几何形状进行了测试。我们分析从每个测试活动中选择的测试用例。冰槽测试使用 3-D 离散元方法 (DEM) 模型重现。每个分析的测试用例被模拟 20 次。每次模拟之间的唯一区别是浮冰的初始位置。数值模拟结果表明，初始浮冰位置的变化会引起冰荷载统计特性的较大变化。通常，可以识别导致结果变化的单个随机交互事件。此类相互作用事件会导致结构前的额外絮凝物堆积，从而影响大部分相互作用长度的载荷统计。观察到的事件发生在数值模拟和物理冰槽测试中。该结果表明，冰罐碎冰试验的重复性较差；不受控制的条件的变化，例如精确的初始絮凝物位置，会导致实验结果发生很大变化。