Life Prediction of Long-Term Creep-Fatigue

长期蠕变疲劳的寿命预测

• 批准号: 61550062
• 负责人: SAKANE Masao
• 金额: $ 1.15万
• 依托单位: Ritsumeikan Universty
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61550062/
• 关键词: Creep-Fatigue; Long Term Hold-Time; Elevated Temperature; Low Cycle Fatigue; Notch Effect; FEM Analysis; Linear Summation Damage Rule; Strain Range Partitioning Method; 寿命予測

The objective of this project is to develop a life prediction method of long term creep-fatigue.The test material used here was a SUS 304 austenitic stainless steel and the push-pull creep-fatigue test was carried out at K. the main conclusions obtained are as follows:(1)We developed a life prediction method of long term creep-fatigue based on the static creep and the no-hold-time low cycle fatigue data. The strain controlled fatigue tests with various hold-times ranging from 5 min and 24 hr were carried out and the fatigue data were generated.The life prediction was made based on the linear summation damage rule with the critical creep/fatigue damage defined in the ASME Code Case for the short and long term creep-fatigue life.The predicted results closely agreed with the experimental creep-fatigue life with the hold-times between 5min and 24hr.(2)The life prediction method developed in the smooth specimen was extended to the notched specimen in the second year of this project.The cyclic elastic-plasticcreep FEM analysis was made for the made for the three types of the circumferential notched specimens whose elastic stress concentration factors were 2.6,4.2 and 6.0. The stress waves analyzed were the triangular stress wave with frequency of 0.1 Hz,the trapezoidal stress wave with 166-min tensile hold-time and slow-slow wave with frequency of 0.0001 Hz. The analysis was made up to 1(1/4)cycle. The creep-fatigue life was predicted based on the calculated local stress/strain at the notched root from linear summation damage rule and the strain range partitioning method. The predicted life agreed with the experimental creep-fatigue life and we concluded that the FEM method was applicable to estimating the long term hold-time and slow-slow fatigue life.

本课题的目的是发展一种长期蠕变疲劳寿命预测方法，试验材料为SUS 304奥氏体不锈钢，在K.（1）提出了一种基于静态蠕变和无保持时间低周疲劳数据的长期蠕变疲劳寿命预测方法。进行了5 min和24 h不同保压时间的应变控制疲劳试验，得到了疲劳数据，并根据ASME规范中定义的蠕变/疲劳临界损伤，采用线性累积损伤准则对该钢的短期和长期蠕变-疲劳寿命进行了预测，预测结果与保压时间下的试验蠕变-疲劳寿命吻合较好。时间在5 min和24 hr之间。（2）在本课题的第二年，将光滑试件的寿命预测方法推广到缺口试件，对弹性应力集中系数分别为2.6、4.2和6.0的三种环向缺口试件进行了循环弹塑性蠕变有限元分析。分析的应力波是频率为0.1 Hz的三角形应力波、拉伸保持时间为166 min的梯形应力波和频率为0.0001 Hz的慢-慢波。分析进行至1（1/4）个循环。根据线性累积损伤准则和应变区间划分法计算出的缺口根部局部应力应变，预测了蠕变疲劳寿命。预测的寿命与实验蠕变-疲劳寿命一致，表明有限元方法适用于预测长期保持时间和慢-慢疲劳寿命。

项目成果

Seiichi,Nishino: "Creep-Fatigue Damage Evaluation and Estimation of Remaining Life of SUS 304 Stainless Steel-An X-ray Method" Proceedings of the 30th Japan Congress Material Research. 155-156 (1986)

Seiichi,Nishino：“SUS 304 不锈钢的蠕变疲劳损伤评估和剩余寿命估算 - X 射线法”第 30 届日本材料研究会会议论文集。

Masao,Sakane: "Frequency and Hold-Time Effects on Low Cycle Fatigue Life of Notched Specimens at Elevated Temperatur" Trans.ASME,J.Eng.Tech.

Masao,Sakane：“频率和保持时间对高温下缺口样品低周疲劳寿命的影响”Trans.ASME，J.Eng.Tech。

西野精一: 第30回材料研究連合講演会前刷集(日本学術会議材料工学研究連合連絡委員会). 155-156 (1986)

Seiichi Nishino：第 30 届材料研究联盟讲座预印本集（日本科学理事会材料工程研究联盟联络委员会）155-156 (1986)。

西野精一: 第30回材料研究連合講演会前刷集(日本学術会議・材料工学研究連合連絡委員会). 155-156 (1986)

Seiichi Nishino：第 30 届材料研究联盟讲座预印本集（日本科学委员会/材料工程研究联盟联络委员会）155-156（1986）。

Masateru,Ohnami: Current Japanese Materials Research,"High Temperature Creep-Fatigue",ed.R.Ohtani,M.Ohnami and T.Inone,the society of Materials scienu,Japan,Elsevrey Applied Science Publisher. V01.3. (1987)

Masateru，Ohnami：当前日本材料研究，“高温蠕变疲劳”，R.Ohtani，M.Ohnami 和 T.Inone 编，材料科学学会，日本，Elsevrey 应用科学出版社。