摘要
强度退化一般具有随机性和不可逆性,而Gamma过程是一个独立非负的增量过程,具有描述强度退化特性的基本属性。由于强度退化过程中,表征退化状态(磨损、裂纹、腐蚀等)的数据很难直接测量,属于典型的缺失数据,而表征材料疲劳性能的P-S-N曲线一般易于获得。因此,本文假定Gamma过程的形状参数为线性函数,并利用材料的P-S-N曲线对Gamma过程的特征参数进行估计,由此建立基于P-S-N曲线的强度退化随机模型。最后,利用20CrMnTi钢的疲劳试验数据对所建模型的有效性进行验证和分析。结果表明,所建模型能够有效描述材料强度退化的宏观趋势。
In general, strength degradation is a stochastic and irreversible process. Gamma process is an independent nonnegative increment process which can be used to describe the characteristics of strength degradation. However, during strength degradation process, the degradation data that characterizes degenerate state （wear, crack, corrosion, etc. ） is often difficult to measure directly, which is the typical missing data. But the P-S-N curve that characterizes material fatigue performance is generally easy to obtain. Therefore,this paper assumes that the shape parameter of Gamma process is a linear function, and estimates the characteristic parameters of Gamma process using material P-S-N curve. Then a stochastic model of strength degradation based on P-S-N curve is established. Finally,the validity of the proposed model is verified and analyzed by using the fatigue test data of 20CrMnTi steel. The results show that this model can effectively describe the macroscopic trend of material strength degradation.
出处
《计算力学学报》
CAS
CSCD
北大核心
2015年第1期118-122,共5页
Chinese Journal of Computational Mechanics
基金
国家自然科学基金(51265025)资助项目
