摘要
针对火电厂常用耐热钢发生疲劳损伤问题时的三个主要宏观特征，即损伤性、概率统计性和损伤局部性，建立起能够全面描述疲劳问题的概率疲劳损伤力学理论与方法．首先，基于不可逆热力学建立的连续损伤力学，研究了疲劳问题的特征性体积单元ＲＶＥ（ＲｅｐｒｅｓｅｎｔａｔｉｖｅＶｏｌｕｍｅＥｌｅｍｅｎｔ）；其次，应用概率统计方法研究了概率性体积单元ＰＶＥ（ＰｒｏｂａｂｉｌｉｓｔｉｃＶｏｌｕｍｅＥｌｅｍｅｎｔ）；最后，根据耐热钢疲劳失效首先是在最薄弱的环节处产生和上述各特征性单元之间的相互影响，从而造成疲劳损伤总是局部性的突出特性，进一步采用数理统计学中最薄弱环节理论，并引入表现各单元间相互影响的局部性算子来推求基于ＰＶＥ单元的概率描述的耐热钢疲劳损伤场．从而建立起描述耐热钢的概率疲劳损伤特性的循环应力应变场、ＰＶＥ单元体表达和概率特性估算的基本表达式．试验与计算结果表明。
In connection with three main macroscopic nature — damaged,statistical and Part — of commen fatigue damaged heat resisting steel in Power station,the issue establishes probability fatigue damaging theory and it's method that can all describle the problem on the fatigue.First analyses the Representative Volume Element(RVE) in the fatigue based on the successive damaging theory that was established with non reversible thermodynamic process.Next studys Probabilistic Volume Element(PVE) with probability statistics.Last because it is clear that fatigue damaging occurs prior in the weakest link and is part as the elements interact,supposes and founds a fatigue damaging field based on the description of the PVE to use the weakest link theory of mathematical statistics and introduce the part operator which shows the interaction of the elements.Therefore founds cycle stresses strains field which describles heat resisting steel feature of probability fatigue damaging and formular which expresses PVE and evolutes probability.Test and result of calculation show this model is more reasonable and practical.
出处
《江西科学》
1998年第4期211-219,共9页
Jiangxi Science
基金
江西省电力工业局资助
关键词
耐热钢
疲劳损伤
概率疲劳损伤
钢结构
Heat resisting steel
Fatigue damaging
Model of probability fatigue damaging
