论文部分内容阅读
采用滑移平面作为临界平面,并以滑移平面上的细观参量作为损伤参量研究材料损伤行为能很好地体现镍基单晶破坏的物理机制.滑移平面上细观参量通过本构模型相互联系,存在较强的多重共线性,导致寿命建模时难以得到合理稳定的材料常数.为此,引入主成分分析方法消除初始细观参量间的多重共线性影响,确定了临界平面主导损伤因子,并基于主导损伤因子建立了寿命模型.对比直接采用初始细观参量建立的寿命模型,该模型形式更为简单,材料常数稳定、合理,反映了细观参量对镍基单晶损伤影响的量化特征.采用760℃与980℃下DD6高温疲劳试验结果对寿命模型进行验证,试验寿命基本落在预测寿命的3倍分散带内.
By using the slip plane as the critical plane and studying the damage behavior of the material by using the mesoscopic parameters of the slip plane as the damage parameters, the physical mechanism of the destruction of the Ni-based single crystal can be well represented.The mesoscopic parameters on the slip plane are obtained through the constitutive model Which leads to the difficulty of obtaining reasonable and stable material constants in the life modeling process.Therefore, the principal component analysis method is introduced to eliminate the influence of multiple collinearity between the initial mesoscopic parameters, and the critical plane dominant damage Factor, and based on the dominant damage factor, the life model was established.Compared with the life model, which was established by directly using the initial mesoscopic parameters, the model was simpler and the material constant was stable and reasonable, which reflected the influence of the mesoscopic parameters on the damage of the nickel-based single crystal Quantification characteristics.The life model was verified by the fatigue test of DD6 at 760 ℃ and 980 ℃, and the test life basically fell within 3 times of the predicted life span dispersion zone.