预压缩量对裂尖蠕变特性的影响

Effect of Pre-compression on Creep Behavior of Cracked Tip

针对核电管道在高温高压环境下工作会产生残余应力和发生蠕变,并造成裂尖力学场的变化,最终对裂纹扩展产生影响。利用ABAQUS有限元分析软件采用预压缩的方法将残余应力引入裂尖区域,在不同的预压缩量下对裂尖处蠕变应力、应变场和蠕变率进行分析。结果表明:随预压缩量增大,裂尖区域的应力、应变、蠕变率都增大,高蠕变区主要集中在裂纹扩展方向上。本文的研究结果可对核电结构材料安全评价和寿命预测提供新思路与依据。

Aiming at the change of crack tip mechanical field induced by residual stress and creep which happens in nuclear power pipeline serving at high temperature and high pressure, at last, the propagation of the crack was affected. The residual stress was introduced to crack tip field by pre-compression method using finite element analysis software ABAQUS.The creep stress, strain field and creep rate in crack tip were analyzed at different amounts of pre-compression. The results show that the stress, strain and creep rate at the crack tip increase with pre-compression increasing. High creep zone mainly locates in the crack growth direction. The research results in the paper can provide new ideas and basis for the safety evaluation and life prediction of nuclear structural materials.