Zr-4合金疲劳裂纹扩展试验及仿真研究

Experimental and simulation study on fatigue crack propagation of Zr-4 alloy

为了准确获得Zr-4合金的疲劳裂纹扩展参数及剩余疲劳寿命,进行了3组紧凑拉伸试验(CT),用Paris公式表征裂纹扩展速率。基于Franc3d和Abaqus的联合仿真验证试验数据的有效性。在确保了扩展参数准确的基础上,探讨了裂纹融合间距对Zr-4合金包壳管剩余疲劳寿命的影响。结果表明:CT试验裂纹扩展路径与联合仿真获得的裂纹路径一致,且模拟结果和理论结果的最大偏差为6.7%,得到裂纹扩展参数C=1.376×10^(10)、m=2.3787;两裂纹半径相同时,间距变化对剩余疲劳寿命无影响,裂纹融合时中间部分的应力强度因子出现较大突变,且大于两侧的应力强度因子。

In order to accurately obtain the fatigue crack propagation parameters and residual fatigue life of Zr-4 alloy,three sets of compact tensile tests(CT)were carried out,and the crack propagation rate was characterized by Paris formula.The joint simulation based on Franc 3d and Abaqus verifies the validity of the experimental data.The effect of crack fusion spacing on the residual fatigue life of Zr-4 alloy cladding tube was discussed after ensuring the accuracy of expansion parameters.The results show that the crack growth path obtained by CT test is consistent with that obtained by co-simulation,and the maximum deviation between the simulated and theoretical results is 6.7%,and the crack growth parameters C=1.376×10^(10) and m=2.3787 are obtained.When the two crack radii are the same,the change of spacing has no effect on the residual fatigue life,and the stress intensity factor in the middle part of crack fusion has a big change,and it is larger than the stress intensity factor on both sides.