一次超载对核电管道裂纹尖端力学场的影响分析

Effect of a single overload on the mechanical field of crack tip in a nuclear power pipeline

针对水锤冲击作用引起的一次超载对核电一回路管道内表面裂纹的影响,本研究以AP1000核电一回路管道为研究对象,利用ABAQUS有限元软件对一次超载作用下的管道裂纹进行有限元计算,得出裂纹在一次超载后裂尖力学场的变化。结果表明,超载在裂纹前缘造成小范围屈服而产生压缩残余应力,导致裂纹前缘张开应力减小,拉伸塑性应变增大,一次超载引起裂纹前缘的残余压缩应力使得裂纹扩展阻力增大,对裂纹扩展有迟滞作用。

With the effect of a single overload induced by water hammer impact on cracks in internal surface of a nuclear power pipeline,an AP1000 nuclear power pipeline was chosen as the research object and the pipe cracks were calculated using finite element analysis software,ABAQUS.And the variation of mechanical field of the crack tip was obtained after a single overload.The results show that the compressive residual stress induced by a small range of yield will cause the decrease of the opening stress and the increase of the tensile plastic strain at the crack tip.And the compressive residual stress generated by a single overload will increase crack propagation resistance,causing a sluggish effect on crack growth at the crack tip.