ABAQUS有限元程序中Jonson-Cook断裂准则与原始模型的差异及对比分析

THE DIFFERENCE BETWEEN THE BUILT-IN JONSON-COOK FRACTURE CRITERION IN ABAQUS FINITE ELEMENT PROGRAM AND THE ORIGINAL CRITERION AS WELL AS A COMPARATIVE ANALYSIS

Johnson-Cook断裂准则包含了应力三轴度、应变率和温度对材料延性的影响,广泛应用于金属材料在高应变率下断裂行为的预测,如爆炸冲击和切削。但是ABAQUS中Johnson-Cook断裂准则(J-C-A)的表达式与原始Johnson-Cook断裂准则(J-C)有差别,在ABAQUS中输入按J-C准则标定的模型参数时便会得到错误的材料断裂性能。不幸的是,部分研究者没注意到这个差别。将J-C断裂准则与J-C-A断裂准则进行了对比,并以Weldox 460 E钢的失效应变为例,展示了J-C的预报效果以及采用J-C模型参数的J-C-A准则的预报效果。最后,以公开文献中的一篇错误应用报道为例,详细说明了错误输入模型参数的预报效果。

Johnson-Cook fracture criterion is widely used to predict the metal fracture at high strain rates in engineering field,such as explosion,shock and cutting,because it incorporates the effect of stress triaxiality,strain rate and temperature on the ductility of a material.However,the Johnson-Cook fracture criterion built in ABAQUS(J-C-A) is different from that of the original expression developed by Johnson and Cook(J-C).Thus,the fracture property of a material will be incorrectly characterized if parameters calibrated according to the J-C criterion are used in ABAQUS in the J-C-A form.Unfortunately,some researchers were unaware of this difference.The expression of the original Johnson-Cook fracture criterion was compared with that built in ABAQUS.The prediction effect of the JC criterion and that of the J-C-A by using parameters calibrated in the J-C form was shown by using the fracture data of Weldox 460 E steel.Finally,the prediction effect of this kind of misinput was revealed by taking a report found in the open literature as an example.