一种改进的Xue-Wierzbicki延性断裂模型  

A modified Xue-Wierzbicki ductile fracture model

作　　者：李文超[1] 景媛 LI Wen-chao;JING Yuan(School of Civil Engineering,Chang′an University,Xi′an 710061,China;School of Highway,Chang′an University,Xi′an 710064,China)

机构地区：[1]长安大学建筑工程学院,陕西西安710061 [2]长安大学公路学院,陕西西安710064

出　　处：《塑性工程学报》2022年第11期127-137,共11页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51908044,51908049);陕西省自然科学基础研究计划(2020JQ-358);长安大学中央高校基本科研业务费专项资金资助项目(300102282107)。

摘　　要：提出了一种改进的Xue-Wierzbicki延性断裂模型以预测高强度结构钢材在多轴应力状态下的延性极限。采用改进的Lee-Mear椭球形孔洞缺陷膨胀理论建立了轴对称拉伸与平面应变拉伸条件下应力三轴度与断裂应变间的函数关系。随后,将上述改进的Lee-Mear断裂应变函数与Xue-Wierzbicki椭圆型Lode角函数结合,以考虑剪切荷载对材料延性极限的影响。提出的断裂模型具有如下两个优点:新模型可准确预测不同应力三轴度与Lode角下高强钢的延性极限;新模型中各参数均有明确的物理含义,可反映材料的力学性能与微观缺陷几何特征。为验证新断裂模型的正确性与精度,利用Q460和Q690高强钢切口试件的断裂试验结果对新模型的参数进行了校准,并计算了各试验试件断裂应变数据点与新模型预测的断裂应变曲面间的平均误差。结果表明,提出的断裂模型可准确预测不同应力状态下Q460和Q690高强钢的延性极限,模型预测结果与两种材料试验结果间的误差平方和分别为4.2%与0.28%,表明新断裂模型具有良好的预测精度。A modified Xue-Wierzbicki ductile fracture model was proposed to predict the ductility limit of high-strength structural steel under multiaxial stress states.A modified Lee-Mear ellipsoidal void defect expansion theory was used to establish the function relationship between stress triaxiality and fracture strain under axisymmetric tension and plane strain tension conditions.And then,the modified Lee-Mear fracture strain function was incorporated into the Xue-Wierzbicki elliptic Lode angle function to consider the effect of shear load on the ductility limit of materials.The proposed fracture model has two advantages as follows:the new model can accurately predict the ductility limit of high-strength steel with different stress triaxialities and Lode angles;parameters in the new model have clear physical meanings,which can reflect the mechanical properties and geometric characteristics of micro defects of materials.To verify the correctness and accuracy of the new fracture model,the fracture test results obtained from notched specimens of Q460 and Q690 high-strength steel were used to calibrate the parameters of new model,and the average error between the fracture strain data point of each test specimen and the fracture strain surface predicted by the new model was calculated.The results show that the proposed fracture model can accurately predict the ductility limit of Q460 and Q690 high-strength steel under different stress states.The square sum of error between prediction results of model and test results of the two materials are 4.2%and 0.28%,respectively,which verifies the good prediction accuracy of the new fracture model.

关 键 词：延性断裂 改进的Xue-Wierzbicki断裂模型 高强度结构钢材 孔洞膨胀理论 

分 类 号：O346[理学—固体力学]