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快速育种反应堆中热条带现象的数学模型。通过使用它，理论上以封闭形式得出了残留的生命分布函数以及裂纹长度分布函数。当组件的故障概率为10^<-5> .2时，由派生分布计算出的剩余寿命为10^8周期。对模型参数进行了灵敏度分析。结果表明，如果温度波动的频谱是窄带类型，则热疲劳裂纹生长的随机方面主要受材料特性的随机性的影响，而不是温度的随机性。3。提出了一种近似方法，以通过使用应力松弛因子在裂纹之间表达应力相互作用的效果。该方法用于分析结构成分包含许多热疲劳裂纹的情况。数值结果表明，随着裂纹间距变大，平均残余寿命缩短。4。从理论上讲，无论温度光谱的形状如何，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。

M.Toyoda: "Life Distribution of Thermal Fatigue Crack Propagation Life under Random Temperature Fluctuations with Wide-Band Spectrum" J.of the Society of Materials Science, Japan. (to be published).

M.Toyoda：“宽带谱随机温度波动下热疲劳裂纹扩展寿命的寿命分布”日本材料科学学会杂志。

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。