Abstract Engineering models, resolved using the finite element method, are used to model through-life changes in material properties and the resulting internal brick stresses in graphite moderator bricks within an advanced gas-cooled reactor (AGR). These models require inputs that describe the loading conditions of the moderator brick and coded relationships describing the behaviour of material properties as the brick ages. A highly multivariate spacio-temporal dataset of displacements, stresses and strains is returned as model output. In this work we describe a computer experiment conducted to study the variability in brick distortion resulting from parameter value uncertainty in the inputs to the model. We identify summary measures of brick shape and conduct global sensitivity analyses to identify the key uncertain parameters driving the variability in brick shape. Our results indicate that different measures of brick shape show sensitivities to different groups of model inputs and suggest that data obtained from core monitoring campaigns can be used to calibrate uncertain parameters in the model. Model calibration and the impact of calibration on predictions of internal brick stresses, which cannot be directly validated, are areas of current research.

中文翻译：

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先进气冷堆慢化剂砖变形研究计算机实验设计与分析

摘要 使用有限元方法求解的工程模型用于模拟材料特性的整个生命周期变化以及先进气冷反应堆 (AGR) 内石墨慢化剂砖的内部砖应力。这些模型需要描述缓和剂砖加载条件的输入和描述随着砖老化而材料特性行为的编码关系。位移、应力和应变的高度多元时空数据集作为模型输出返回。在这项工作中，我们描述了一个计算机实验，用于研究模型输入中参数值不确定性导致的砖变形的可变性。我们确定砖块形状的汇总测量并进行全局敏感性分析，以确定驱动砖块形状变化的关键不确定参数。我们的结果表明，砖块形状的不同测量显示出对不同组模型输入的敏感性，并表明从核心监测活动中获得的数据可用于校准模型中的不确定参数。模型校准和校准对内部砖应力预测的影响，无法直接验证，是当前的研究领域。