基于裂纹尖端塑性区参量的SE(T)试样的拘束度研究

Research on the constraint of SE(T)specimen based on crack tip plastic zone parameters

以X80高强管线钢为研究对象,结合数值分析和解析法,研究了基于裂纹尖端塑性区几何特征提出的拘束参数■、■、■、■对于不同SE(T)试样裂纹尖端应力场的表征效果,并通过断裂韧性试验量化了面内拘束和面外拘束效应对X80管线钢的SE(T)试样断裂韧性的影响,建立基于裂纹尖端塑性区的面内和面外统一拘束参数■、■、■、■与应力强度因子K的关系,确定拘束参数与T应力(T_(11)和T_(33))之间的解析关系,并通过有限元模拟和理论分析提出了小范围屈服条件下的断裂韧性预测方法.

In this paper,X80 high-strength pipeline steel is taken as the research object.Combined with numerical and theoretical analysis,the constraint parameters■、■max、■、■based on the geometric characteristics of the plastic zone at the crack tip are studied for the crack tip stress of different single edge notch tensile SE(T)specimens.The in-plane and out-of-plane constraint effects on the fracture toughness of SE(T)specimens of X80 pipeline steel were quantified by fracture toughness tests.The relationship between■、■max、■、■,the uniform of in-plane and out-of-plane constraint based on the plastic zone at the crack tip,and the stress intensity factor K were established.The analytical relationship between the constraint parameters and the T stress(T_(11) and T_(33))was determined,and the fracture toughness prediction methods under small-scale yield conditions were proposed through finite element simulation and theoretical analysis.