基于有限元方法的航空发动机叶片应力强度因子计算  

Stress intensity factor calculation for aero-engine compressor blade with finite element method

作　　者：李春旺[1,2] 罗秀芹[2] 杨百愚[2] 张贵斌 李亚智[1] 张忠平[2] 

机构地区：[1]西北工业大学航空学院,西安710072 [2]空军工程大学理学院,西安710051 [3]西安航空动力股份公司军事代表室,西安710021

出　　处：《应用力学学报》2013年第3期373-377,475,共5页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(10804130)

摘　　要：为研究叶片裂纹尖端的应力奇异性,以某型航空发动机压气机叶片为例,利用有限元方法研究了叶片裂纹尖端应力强度因子的计算方法,并研究了旋转叶片振动状态下裂尖应力强度因子随裂纹长度的变化规律。建立计算模型时,在裂纹尖端划分了三维奇异单元,在裂尖外围划分了过渡单元。计算结果表明:研究旋转叶片振动状态下的裂尖应力奇异性,仅利用I型应力强度因子就具有足够的精度;对于同一裂纹,绝大多数情况下叶盆面应力强度因子大于叶背面应力强度因子,故研究叶片应力强度因子时只需研究叶盆应力强度因子即可;随着裂纹扩展,叶盆面I型应力强度因子不断增大。本文的研究方法及结论为进一步研究叶片的裂纹扩展规律及损伤容限奠定了基础。In order to study the stress singularity at the blade crack tip,an aero-engine compressor blade with crack is taken as example,stress intensity factor from the finite element method is calculated.Then,the change of the stress intensity factor with the crack length is studied.To construct the calculation model,the three dimensional singular elements at crack tip and the transition elements around crack tip are meshed.The conclusions are that only mode I stress intensity factor of concave is adequate to describe the stress singularity for the blade,and that the mode I stress intensity factor of concave increases with the crack propagation.Both the stress intensity factor calculation method and the conclusions of the present paper provide the base for further investigation of the crack growth rate and the damage tolerance of the blade.

关 键 词：含裂纹叶片 应力强度因子 有限元方法 三维奇异单元 过渡单元 

分 类 号：V235.1[航空宇航科学与技术—航空宇航推进理论与工程]