Influence of foreign object damage on fatigue crack growth of gas turbine aerofoils under complex loading conditions
Influence of foreign object damage on fatigue crack growth of gas turbine aerofoils under complex loading conditions
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DOI：
10.1111/j.1460-2695.2008.01238.x
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发表时间：
2008-05
影响因子：
3.7
通讯作者：
R. Hall;J. Byrne;T. Zhao;J. Tong
中科院分区：
文献类型：
--
作者：
R. Hall;J. Byrne;T. Zhao;J. Tong
外物损伤（FOD）是航空发动机叶片寿命的主要限制因素之一，其中机翼前缘尤其易受影响。在这项工作中，一个通用的边缘“翼型”的几何形状被用于早期疲劳裂纹扩展行为的研究，由于FOD低周疲劳（LCF），高周疲劳（HCF）和组合LCF和HCF加载条件下。采用有限元法分析了FOD引起的残余应力。将沿裂纹路径沿着的纵向残余应力分量作为节点温度分布引入，并用于应力强度因子范围的修正。裂纹扩展监测使用nanodirect电流电位降（DCPD）系统和裂纹扩展速率与考虑残余应力的校正应力强度因子。结果进行了讨论方面的作用，残余应力的疲劳裂纹扩展的表征。FOD试样中的小裂纹扩展行为仅在残余应力被考虑到应力强度因子的计算中才被揭示，该应力强度因子是LCF、HCF和LCF + HCF组合加载条件的共同特征。
Foreign object damage (FOD) has been identified as one of the main life limiting factors for aeroengine blades, with the leading edge of aerofoils particularly susceptible. In this work, a generic edge 'aerofoil' geometry was utilized in a study of early fatigue crack growth behaviour due to FOD under low cycle fatigue (LCF), high cycle fatigue (HCF) and combined LCF and HCF loading conditions. Residual stresses due to FOD were analyzed using the finite element method. The longitudinal residual stress component along the crack path was introduced as a nodal temperature distribution, and used in the correction of the stress intensity factor range. The crack growth was monitored using a nanodirect current potential drop (DCPD) system and crack growth rates were correlated with the corrected stress intensity factor considering the residual stresses. The results were discussed with regard to the role of residual stresses in the characterization of fatigue crack growth. Small crack growth behaviour in FODed specimens was revealed only after the residual stresses were taken into account in the calculation of the stress intensity factor, a feature common to LCF, HCF and combined LCF + HCF loading conditions.