涡轮叶片随机分布腐蚀坑的应力分布规律研究

Research on Stress Distribution Law of Randomly Distributed Corrosion Pits on Turbine Blades

对于在沿海地区服役的航空发动机,其涡轮叶片等热端部件常处于高温、高压、易腐蚀的工作环境中,涡轮部件表面极易发生一种热腐蚀,从而导致涡轮部件材料力学性能恶化,强度降低。基于涡轮叶片热腐蚀形貌,通过统计腐蚀坑的分布规律,建立了多腐蚀坑的有限元模型,研究了随机分布腐蚀坑的应力分布规律。结果表明:腐蚀坑的尺寸及间距分布符合对数正态分布规律,对于规则分布、尺寸不规则分布、位置不规则分布和随机分布4种规则下的多腐蚀坑,应力集中区域均出现在腐蚀坑密集区域,且在与力加载垂直方向上出现明显的干涉现象。

For aero-engines serving in coastal areas,hot-end components such as turbine blades are in a high-temperature,highpressure,and corrosive operating environment.The surface of turbine components is particularly susceptible to thermal corrosion,which can lead to the deterioration of the mechanical properties of turbine component materials and reduction in structural strength.The distribution law of corrosion pits was analyzed and the finite element model with multiple corrosion pits was established to study the distribution law of stress along with the randomly distributed corrosion pits based on the thermal corrosion morphology diagram of turbine blades in this study.The results indicate that the size and spacing distribution of corrosion pits conform to the lognormal normal distribution law.For multiple corrosion pits under four distribution rules,i.e.regular distribution,irregular size distribution,irregular position distribution,and random distribution,the stress concentration areas appeared in the densely populated areas of corrosion pits,and obvious interference phenomena appeared in the direction perpendicular to the force loading.