Structural Reliability Assessment for Thermal Fatigue Phenomena in Fast Breeder Reactors Based upon Probabilistic Fracture Mechanics

基于概率断裂力学的快中子增殖堆热疲劳现象结构可靠性评估

• 批准号: 05680416
• 负责人: MATSUSHITA Yasuo
• 金额: $ 1.34万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05680416/
• 关键词: Fast Breeder Reactor; Thermal Striping; Thermal Fatigue; Probabilistic Fracture Mechanics; Structural Reliability; Probabilistic Model; 余寿命分布; 不規則き裂進展

1. A mathematical model to analyze thermal striping phenomena in fast breeder reactors is constructed based upon a probabilistic fracture mechanics. By the use of it, a residual life distribution function, as well as a crack length distribution function, is theoretically derived in a closed form. The residual life calculated by the derived distribution is of order of 10^8 cycles when the failure probability of the component is 10^<-5>.2. Sensitivity analysis with respect to model parameters is performed. The result indicates that, if the spectrum of temperature fluctuation is of narrow-band type, the random aspect of thermal fatigue crack growth is mainly affected by the randomness of material's property rather than by the randomness of temperature.3. An approximation method is proposed to express stress interaction effect between cracks by the use of a stress relaxation factor. The method is applied to analyze the case in which the structural component contains many thermal fatigue cracks. The numerical result shows that the mean residual life is shortened as the crack spacing becomes larger.4. It is theoretically clarified that our model is applicable regardless of the shape of the temperature spectrum.

1. 基于概率断裂力学，构建了分析快中子增殖堆热条纹现象的数学模型。通过使用它，理论上可以以闭合形式导出剩余寿命分布函数以及裂纹长度分布函数。当部件的失效概率为10^<-5>.2时，由导出的分布计算出的剩余寿命约为10^8个周期。进行关于模型参数的敏感性分析。结果表明，如果温度波动谱为窄带型，则热疲劳裂纹扩展的随机性主要受材料性能随机性的影响，而不是温度随机性的影响。 3．提出了一种利用应力松弛因子来表达裂纹之间的应力相互作用效应的近似方法。该方法适用于分析结构件含有较多热疲劳裂纹的情况。数值结果表明，裂纹间距越大，平均剩余寿命越短。4．从理论上讲，无论温度谱的形状如何，我们的模型都适用。

项目成果

Hiroaki Tanaka: "Random Thermal Fatigue in Fast Breeder Reactor-A Narrow-Band Spectrum-" Nuclear Engineering and Design. (掲載予定).

Hiroaki Tanaka：“快中子增殖反应堆中的随机热疲劳-窄带频谱-”核工程与设计（待出版）。

豊田倫子: "広帯域の温度変動下での疲労き裂進展について" 第12回材料・構造信頼性シンポジウム講演論文集. 119-124 (1993)

Michiko Toyoda：“关于大范围温度波动下的疲劳裂纹扩展”第 12 届材料与结构可靠性研讨会论文集 119-124 (1993)。

H.Tanaka: "Random Thermal Fatigue in Fast Breeder Reactor - A Narrow-Band Spectrum -" Nuclear Engineering and Design. (to be published).

H.Tanaka：“快中子增殖反应堆中的随机热疲劳 - 窄带频谱 -”核工程与设计。

Hiroaki Tanaka: "Probabilistic Analysis of Thermal Fatigue Pheromenon in FBR Based Upon Probabilistic Fracture Mechanics" Trans.of SMiRT12. M. 123-134 (1993)

Hiroaki Tanaka：“基于概率断裂力学的 FBR 中热疲劳现象的概率分析”Trans.of SMiRT12。

H.Tanaka: "Probabilistic Analysis of Thermal Fatigue Phenomenon in FBR Based Upon Probabilistic Fracture Mechanics" Trans. of SMiRT12. Vol.M. 175-180 (1993)

H.Tanaka：“基于概率断裂力学的FBR热疲劳现象的概率分析”Trans。