采用Gurson-Tvergaard-Needlman的连续损伤材料本构模型(GTN模型),考虑微观孔洞的影响,利用ABAQUS有限元软件对锆材光滑和不同缺口半径的轴对称拉伸试样进行了数值模拟,研究了试样颈缩过程中微孔洞的演化过程,分析了损伤的起始点和韧性断裂的宏观影响因素.模拟计算结果显示,GTN模型能合理地模拟试样拉伸过程中的颈缩现象,Birdgman公式对光滑试样小应变条件下应力三轴度预测比较准确,但对缺口试样的应力多轴度预测误差较大；试样中裂纹开始形成阶段孔洞长大聚合效果显著,而形核作用相对较弱；缺口半径不同,试样起裂位置不同；等效塑性应变和应力三轴度是影响塑性断裂的主要因素,两者共同决定了试样的塑性断裂过程.%Non-linear finite element analysis of different smooth and notched axisymmetric specimens of Zirconium has been carried out by using ABAQUS. The constitutive relation of Gurson-Tvergaard-Needlman model was adopted in the simulation in consideration of the influence of mi-crocosmic void. Void growth and initiation of ductile crack in the nonuniform multaxial stress fields of smooth and notched bars were studied. Good correlation of experiments and numerical simulations was achieved. Based on the numerical results, the stress triaxiality of different specimens was compared with the value of Bridgman formula and it was shown that there are distinct difference between this function and the numerical value. The voids growth acutely when the crack initiation, while few new voids nucleate. The crack initiated at different places in different notched bars. The equivalent plastic strain and the stress triaxiality play great role on initiation of ductile fracture.
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