【作者】 魏佳佳； 杨未柱； 李涛； 孙景国； 李磊； 王睿；

【Author】 WEI Jiajia;YANG Weizhu;LI Tao;SUN Jingguo;LI Lei;WANG Rui;School of Mechanics,Civil Engineering and Architecture,Northwestern Polytechnical University;Shenzhen Research Institute of Northwestern Polytechnical University;The 703rd Research Institute of China Shipbuilding Corporation;

【机构】 西北工业大学力学与土木建筑学院； 西北工业大学深圳研究院； 中国船舶集团有限公司第七〇三研究所；

【摘要】 涡轮叶片工作环境严苛,其寿命评估对燃气轮机运行安全至关重要。基于特征模拟件试验开展叶片寿命评估成本较低,且能真实地模拟叶片关键部位的复杂应力状态,可为叶片寿命评估提供有力支撑。针对燃气轮机涡轮叶片尾缘气膜孔部位,基于材料一致、几何相似和寿命等效等设计原则提出了疲劳特征模拟件的设计方法,建立了模拟件设计流程。依据叶片强度的有限元分析结果,以气膜孔孔周和虚拟裂纹扩展方向上第一主应力分布变化一致为目标,对特征模拟件进行了迭代设计。开展了特征模拟件低周疲劳试验,并采用考虑局部应变分布影响的M-H模型进行了疲劳寿命预测,预测结果与试验结果相比均在3倍分散带内。同时断口分析结果显示,特征模拟件裂纹起源及扩展方向与有限元分析结果吻合,验证了设计方法的合理性。更多还原

【Abstract】 Turbine blade operate in harsh environments,and its life assessment is critical to the safety of gas turbine operation.The cost of blade life evaluation based on the feature simulation experiment is low,and the complex stress state of key parts of the blade can be realistically simulated,which can provide strong support for the blade life assessment.Aiming at the structure of jet holes at the tailing edge of gas turbine blades,a design method of feature simulation specimen for fatigue is proposed based on the design principles of consistent materials,geometric similarity and life equivalence,and the design process of simulation specimen is established.According to the results of finite element analysis for blades strength,the feature simulation specimen is iteratively designed with the goal of consistent changes in the first principal stress distribution around the jet hole and in the virtual crack propagation direction.The low-cycle fatigue experiment of the feature simulation specimen was carried out by using the M-H model considering the influence of local strain distribution was used to predict the fatigue life,and the predicted results were all within the three-fold dispersion band compared with the results of experiment.At the same time,the results of fracture analysis shows that the crack origin and propagation direction of the feature simulation specimen are consistent with the results of finite element analysi、,which verifies the rationality of the design method.更多还原