In the field of nuclear engineering, Printed Circuit Heat Exchangers (PCHEs) have become increasingly popular and the structural integrity assessment of these key power plant components is crucial. As part of the structural integrity assessment, creep rupture analysis considers the interaction of cyclic plasticity and creep behaviour, which is vital for components subjected to cyclic thermal-mechanical loads. The Linear Matching Method (LMM) framework has included a creep rupture module based on an extended shakedown algorithm, which has been adopted by several researchers. However, the current LMM framework mainly relies on linear extrapolation and requires users to provide a large amount of data points to estimate the rupture stress. This paper introduces a Unified Creep Rupture Equation (UCRE) for characterizing the creep rupture curves of diverse steel types. The UCRE is implemented in an extended shakedown algorithm and integrated into the LMM framework. The numerical method is validated through a comparative analysis, wherein the estimated rupture curves are compared with those provided in the ECCC data sheet, as well as against alternative numerical models. Shakedown and creep rupture analyses are then performed on a PCHE core. The proposed method facilitates the parametric study of changing materials and the process of material selection. Various geometric configurations are also considered and the proposed unitary cell model is verified by comparing the results with ones from full FE models. The UCRE has been proved to be an accurate engineering tool for the prediction of rupture strengths while the LMM framework has gained improved usability and versatility for engineering applications.

中文翻译：

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基于线性匹配方法框架的印刷电路换热器的安定和蠕变断裂分析

在核工程领域，印刷电路热交换器（PCHE）越来越受欢迎，这些关键发电厂部件的结构完整性评估至关重要。作为结构完整性评估的一部分，蠕变断裂分析考虑了循环塑性和蠕变行为的相互作用，这对于承受循环热机械载荷的部件至关重要。线性匹配方法 (LMM) 框架包括基于扩展安定算法的蠕变破裂模块，已被多名研究人员采用。然而，目前的LMM框架主要依赖于线性外推法，需要用户提供大量数据点来估计破裂应力。本文介绍了统一蠕变断裂方程 (UCRE)，用于表征不同钢种的蠕变断裂曲线。UCRE 采用扩展的安定算法实现，并集成到 LMM 框架中。该数值方法通过比较分析进行验证，其中将估计的破裂曲线与 ECCC 数据表中提供的曲线以及替代数值模型进行比较。然后对 PCHE 岩心进行安定和蠕变断裂分析。所提出的方法有利于改变材料和材料选择过程的参数化研究。还考虑了各种几何配置，并通过将结果与完整有限元模型的结果进行比较来验证所提出的单一单元模型。UCRE 已被证明是预测断裂强度的准确工程工具，而 LMM 框架则提高了工程应用的可用性和多功能性。