Abstract Available experimental efforts on ceramic pebble beds and their associated constitutive equations are necessarily derived from single-effect tests where one parameter is varied and its effects are isolated and studied separately (e.g., using constant temperatures and externally applied loads). These experiments are incapable of reproducing the true multiple/synergistic effects of the physics that occur in real blankets, and the phenomena arising from the interactions of single effects are yet to be discovered. It is unclear whether the combined effect of plasticity and creep under reactor-relevant loading conditions will either enable the altered pebble bed packing configuration to reach an acceptable self-regulating temperature state or significantly deteriorate its heat transfer efficiency and subsequent tritium release. Therefore, studying the isolated thermal and mechanical effects is not sufficient to predict pebble bed behavior. It is the coupling and interdependence between the dynamic thermal and mechanical fields, as well as the synergistic effects between the various modes of deformation, that are key to fully understanding and predicting pebble bed behavior in a realistic fusion environment. However, previous mock-up experimental campaigns thus far have suffered from critical shortfalls that have severely hamstrung their scientific impact. The lack of experimental data that incorporate multiple-effects interactions in addition to the complexity of building a full-scale breeder unit mock-up triggered the need for this experimental effort. The body of work presented in this paper serves to (1) establish and validate the practicality of various volumetric heating simulation techniques for representative thermomechanical study, (2) recreate a prototypical breeder unit’s thermal-hydraulic behavior using a scaled-down reduced-activation ferritic steel box with optimized manifold design, (3) evaluate the thermomechanical properties of the pebble bed using a novel nonintrusive in situ tactile-pressure-sensing technology capable of generating real-time contact pressure maps that reveal spatial and temporal stress evolution, and (4) develop and benchmark a thermomechanical finite element method code that is able to predict the pebble bed’s thermomechanical evolution under the effects of creep and thermal cycling. The results of this study not only present novel experimental techniques and data that enhance our understanding of synergistic thermomechanical interactions and effects, but they also provide valuable data to serve as a basis for validation of the most recent pebble bed numerical models. Finally, it is worth mentioning that this work is part of a compendium around the Thermomechanical Solid Breeder Multiple Effects Experiment experimental campaign, known as TESOMEX. While this paper primarily focuses on novel heating and instrumentation techniques along with their opportunities and limitations, the other two papers shed more light on the prototypical thermomechanical evolution, pebble sintering, and possible modes of failure.

中文翻译：

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具有体积加热和 FEM 基准分析的热机械固体繁殖多效实验 (TESOMEX)

摘要 陶瓷卵石床及其相关本构方程的可用实验工作必然来自单效应测试，其中一个参数是变化的，其效应被隔离和单独研究（例如，使用恒定温度和外部施加的载荷）。这些实验无法再现真实毯子中物理的真正多重/协同效应，并且尚未发现由单一效应相互作用产生的现象。目前尚不清楚在反应器相关负载条件下塑性和蠕变的综合影响是否会使改变的球床填料配置达到可接受的自调节温度状态或显着降低其传热效率和随后的氚释放。所以，研究孤立的热和机械效应不足以预测卵石床的行为。动态热场和机械场之间的耦合和相互依赖，以及各种变形模式之间的协同效应，是在现实融合环境中充分理解和预测卵石床行为的关键。然而，迄今为止，之前的模拟实验活动严重不足，严重阻碍了其科学影响。除了构建全尺寸育种单元模型的复杂性之外，还缺乏包含多效应相互作用的实验数据，这引发了对这项实验工作的需要。这项研究的结果不仅提供了新的实验技术和数据，增强了我们对协同热机械相互作用和效应的理解，而且还提供了有价值的数据，作为验证最新球床数值模型的基础。最后，值得一提的是，这项工作是围绕热机械固体育种机多效实验实验活动（称为 TEOMEX）的纲要的一部分。虽然本文主要关注新的加热和仪器技术及其机会和局限性，但其他两篇论文更深入地阐明了原型热机械演变、卵石烧结和可能的故障模式。但它们也提供了有价值的数据，作为验证最新的卵石床数值模型的基础。最后，值得一提的是，这项工作是围绕热机械固体育种机多效实验实验活动（称为 TEOMEX）的纲要的一部分。虽然本文主要关注新颖的加热和仪器技术及其机会和局限性，但另外两篇论文则更多地阐明了原型热机械演变、卵石烧结和可能的故障模式。但它们也提供了有价值的数据，作为验证最新的卵石床数值模型的基础。最后，值得一提的是，这项工作是围绕热机械固体育种机多效实验实验活动（称为 TEOMEX）的纲要的一部分。虽然本文主要关注新颖的加热和仪器技术及其机会和局限性，但另外两篇论文则更多地阐明了原型热机械演变、卵石烧结和可能的故障模式。