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采用单晶正交各向异性弹性本构关系,分析了三维晶体取向对单晶涡轮叶片应力分布、蠕变寿命、低周疲劳寿命及叶尖径向位移的影响.结果表明,三维晶体取向对单晶叶片上述性能存在显著影响,且3个取向角之间相互耦合,偏差角对叶片性能的影响随着随机角的方位而变化,随机角对叶片性能的影响也随着偏差角的角度而不同.在此基础上,应用ISIGHT构建了单晶叶片全三维取向优化平台,以蠕变寿命、低周疲劳寿命及叶尖最大径向位移为优化目标,采用邻域培植多目标遗传算法进行了叶片三维取向优化,所得Pareto解聚集在偏差角12°的区域内.选择寿命最长的Pareto解作为最优解,相对于初始强度计算点,蠕变寿命提高6倍,低周疲劳寿命提高37倍,叶尖最大径向位移减小2.5%.
The effect of three-dimensional crystal orientation on the stress distribution, creep life, low cycle fatigue life and tip radial displacement of single crystal turbine blades was analyzed by single-crystal orthogonal anisotropy elastic constitutive equation.The results show that the three-dimensional crystal orientation pair The above-mentioned properties of the single crystal blade have significant effects, and the three orientation angles are mutually coupled. The influence of the deviation angle on the blade performance varies with the azimuth of the random angle. The influence of the random angle on the blade performance also varies with the angle of the deviation angle Different.Based on this, the full three-dimensional orientation optimization platform of single crystal blade was constructed by using ISIGHT, and the optimization target was creep life, low cycle fatigue life and maximum radial displacement of blade tip. The multi-objective genetic algorithm The three-dimensional orientation of the blade is optimized and the resulting Pareto solution is aggregated within a deviation angle of 12. The Pareto solution with the longest lifetime is selected as the optimal solution with a 6-fold increase in creep life and a 37% reduction in low-cycle fatigue life relative to the initial strength calculation Times, the maximum radial displacement of tip reduced by 2.5%.