火焰筒掺混孔边裂纹在变温情形下的J积分、C(t)积分

针对某型火焰筒高温条件下裂纹萌生以及扩展问题，利用含裂纹圆孔模型和有限元方法分别在稳定温度场和瞬态变化温度场下进行数值模拟，通过J积分和C（t）积分结果估计裂纹尖端场强度。J积分和C（t）积分在两种情况下表现出明显差异，表明瞬态温度场下的裂纹扩展与稳态温度场下的情况显著不同。对这种现象进行了初步探讨，利用J积分和C（t）积分判断火焰筒掺混孔边裂纹扩展趋势。

Research on J and C (t) Integrals of Crack at the Edge of a Dilution Hole

This paper analyzes the crack initiation and fatigue propagation at the edge of a dilution hole in combustor's liner at high temperature.A plane model with a crack at the edge of a round hole is built at high temperature and under anisothermal condition,and the numerical simulations via finite element method at stable temperature and transient temperature are performed respectively.Furthermore,the comparison between evaluations of stress intensity at crack tip respectively by J-integral and C(t)-integral is made.According to the analysis,it is found that there is evident difference between the results J-integral and C(t) integral under the conditions of stable and transient temperature.This phenomenon is tentatively discussed for the judgment of the crack fatigue propagation.