Abstract The fuel pins are the first containment barriers of a sodium fast reactor, and their integrity have to be preserved during dynamical loads, like earthquake events but also during the transport and handling of fuel sub-assemblies. The purpose of this paper is to understand the dynamical behavior of the fuel pins. A dedicated test bed has been used. Three different regimes of damping, dry or viscous depending of the displacement amplitude, are identified during the tests on fuel pins and explained by a simple analytical model. A complex finite element model is proposed and confronted to the experiment and lead to a better comprehension of the fuel pin non linear damping.

中文翻译：

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钠快堆燃料棒的非线性阻尼：实验分析和数值模型化

摘要 燃料棒是钠快堆的第一道安全壳屏障，其完整性必须在动态载荷（如地震事件）以及燃料组件的运输和处理过程中保持。本文的目的是了解燃料棒的动力学行为。使用了专用的测试台。在燃料棒测试期间确定了三种不同的阻尼机制，干态或粘性取决于位移幅度，并通过简单的分析模型进行解释。提出了一个复杂的有限元模型并面对实验，从而更好地理解燃料棒非线性阻尼。