基于断裂力学的GH3535合金蠕变裂纹扩展模拟和寿命评估
Simulation and Life Evaluation of Creep Crack Propagation in GH3535 Alloy based on Fracture Mechanic
在第四代先进反应堆钍基熔盐堆(TMSR)中，高温含缺陷构件的寿命预测是结构完整性评估的重要环节。在该研究中，首先基于随时间变化的蠕变断裂力学，采用有限元分析软件Abaqus的围道积分方法计算蠕变断裂参量C*，结合Python语言编写的自动化分析程序，预测了GH3535合金紧凑拉伸试样C(T)的蠕变裂纹扩展 (CCG)。将数值计算结果和蠕变裂纹扩展试验的结果进行对比验证，分析了数值模拟计算中的不确定性来源。然后建立了GH3535合金的时间相关失效评定图(TDFAD)，并从有限元计算结果提取并计算裂纹扩展过程中的应力强度因子K和参考应力，最后对缺陷试样进行了寿命评估。在蠕变裂纹扩展数值模拟中，蠕变断裂参量C*仅能描述裂纹扩展阶段，而裂纹萌生阶段采用试验数据拟合的裂纹萌生时间进行描述。高温含缺陷结构的寿命跟缺陷的尺寸、载荷、裂纹扩展速率等因素相关，通过数值模拟方法可获取这些因素的影响。该研究结果解释了GH3535合金的蠕变裂纹行为，为TMSR高温含缺陷结构的寿命预测提供了工程指导。
核反应堆工程材料科学
GH3535蠕变裂纹扩展缺陷评估钍级熔盐堆
王雯,王晓艳,李志军.基于断裂力学的GH3535合金蠕变裂纹扩展模拟和寿命评估[EB/OL].(2025-08-01)[2025-10-04].https://chinaxiv.org/abs/202508.00019.点此复制
[Background]: The life assessment of high-temperature components with defects in the thorium molten salt reactor (TMSR), which is one of the fourth-generation reactors, is a crucial part of structural integrity assessment. [Purpose]: This study aims to simulate the creep crack growth (CCG) of compact tensile specimens C(T) and to carry out a life assessment of these specimens, providing engineering guidance for life prediction of defect structures at elevated temperatures in TMSR. [Methods]: The study firstly simulated the creep crack growth (CCG) of compact tensile specimens C(T) by using the Contour integral evaluation method in finite element analysis (FEA). Aand an automated analysis program was written in Python, based on time-dependent creep fracture mechanics to calculate the creep fracture parameter C*. A time-dependent failure assessment diagram (TDFAD) for GH3535 alloy was established, and the stress intensity factor K and reference stress _ref were extracted and calculated from FEA results. At last, a life assessment was carried out on a C(T) specimen. [Results]: The comparison between experimental data and simulation results by using the creep fracture parameter C* demonstrates that the finite element analysis method can effectively simulate the crack propagation in the specimens. The TDFAD of GH3535, combined with FEA, visually presents the process of crack propagation leading up to equipment failure. [Conclusions]: The research results explain the behavior of GH3535 alloy's creep cracks and provide engineering guidance for life prediction of defect structures at elevated temperatures in TMSR, ensuring the safety and reliability of the reactor's high-temperature components.
GH3535Creep crack propagationDefect assessmentThorium molten salt reactor (TMSR)
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