高温构件蠕变损伤的概率计算及概率损伤图

PROBABILISTIC CREEP DAMAGE AND PROBABILISTIC DAMAGE DIAGRAM FOR HIGH TEMPERATURE COMPONENTS

由于材料性质以及操作条件的随机性 ,高温构件的蠕变损伤也同样具有随机性。文中根据概率计算的基本原理和高温构件蠕变损伤确定性解 ,得到蠕变损伤的概率方程。探讨各参数的分布规律 ,利用K S检验方法 ,对高温材料数据进行全面的检验 ,包括高温材料的蠕变系数和指数、损伤系数和指数 ;同时 ,对操作温度以及高温构件的蠕变损伤进行检验 ,认为这些参数分别符合正态或对数正态分布。在全面考虑各参数的随机性和相关性基础上 ,最终获得高温构件的概率蠕变损伤解。为了表达它们之间的关系 ,以期最终达到高温构件寿命预测和可靠性评估的目的 ,考虑两个参数 ,确定性时间t和随机性的炉管损伤值D。将它们之间的关系表述成为t—D—f(D)图 ,形成高温构件的概率损伤图 ,清晰地勾画出不同时间D值的概率分布关系 。

Because of the randomness of material properties and operation conditions the creep damage of high temperature component is also stochastic. Based on the principal of probabilistic calculation and deterministic solution of creep damage of high temperature components, the probabilistic model of creep damage was obtained. The distribution property of all parameters was discussed by use of K S check method. The creep coefficients, creep exponents, damage coefficients, damage exponents, temperature and creep damage of high temperature components were checked. The results verified that these parameters were fit for normal distribution or logarithm normal distribution. Considering the randomness and correlation of every parameter in detail the probabilistic calculation solution of creep damage was proposed. To realize the aim of the life prediction and reliability assessment for high temperature component, two parameters of determined time t and stochastic damage D were put together and the probabilistic damage diagram was formed by t-D-f(D) . Probabilistic damage diagram clearly showed the probabilistic distribution relation at different time. The study supplied the basis with the reliability analysis and probabilistic life assessment of high temperature components.