蠕变对应力腐蚀裂纹尖端应力应变的影响

Effects of Creep on Stress and Strain of Stress Corrosion Crack Tip

裂尖应力和应变是影响核电关键焊接接头应力腐蚀开裂速率的主要因素之一,裂尖高应变区的金属蠕变会造成裂尖力学场的变化,并对应力腐蚀开裂速率产生影响。本文以紧凑拉伸试样为研究对象,采用ABAQUS有限元软件,分析了裂尖高应变区蠕变对裂尖应力和应变的影响。结果表明,蠕变能显著缓解裂尖区域的应力集中现象,而对裂尖区域的等效塑性应变影响较小。裂纹尖端不同方向处的应力随蠕变时间的增加而减小,裂尖蠕变量随着裂尖距离的增大而减小,0°方向的应力值和蠕变量最大。

Stress and strain at crack tip are one of the key parameters that affect the stress corrosion cracking rate of nuclear power key welded joints. The metal creep at the crack tip in high stress zone causes the change of mechanical field at the crack tip and affects the stress corrosion cracking rate. In this paper, The compact tension specimen was taken as object, and the effects of creep at the crack tip in high stress zone on the stress, strain of crack tip were analyzed by ABAQUS finite element software. The results show that the creep can significantly reduce stress concentration at the crack tip, and it has little effect on the equivalent plastic strain at crack tip. The stress at different directions at the crack tip decreases with the increase of creep time, the creep strain decreases with the increase of the distance from crack tip, and the stress, creep strain at 0° direction is the biggest.