一种考虑剪切作用机制的Johnson-Cook断裂准则  

A modified Johnson-Cook fracture criterion considering shear effect

作　　者：诸楠 赵震[1] 庄新村[1] 

机构地区：[1]上海交通大学塑性成形技术与装备研究院,上海200030

出　　处：《锻压技术》2015年第8期127-131,共5页Forging & Stamping Technology

基　　金：国家科技重大专项(2013ZX04002081)

摘　　要：基于已有的Johnson-Cook断裂准则,提出了新的考虑剪切作用机制的断裂准则。设计了不同温度、不同应变速率以及不同应力三轴度下的试验,对不同试验条件下的宏观断口进行分析。试验结果表明,随着温度的升高和应变速率的增大,断裂时刻的断裂应变减小。结合有限元模拟,确定了新的断裂准则中的断裂参数,获得了新的断裂准则。利用ABAQUS子程序功能将新的断裂准则嵌入有限元软件,并对高速棒料剪切工艺进行有限元模拟,模拟结果可以较好地表征棒料剪切断口的宏观特征,对比有限元模拟与试验的载荷-位移曲线验证了新的断裂准则的可靠性。A new fracture criterion considering shear effect was proposed based on Johnson - Cook fracture criterion. Experiments under different temperatures, strain rates and stress triaxiality were designed and carried out. Macro fractures under different conditions were an- alyzed. Results show that fracture strain at the fracture time decreases with the increase of temperature and strain rate. New fracture criterion was obtained and parameters were determined by FEM software. It was embedded in FEM software by ABAQUS subroutine. The cutting process of high speed bar was simulated numerically. FEM results show good consistency with experimental features and the new fracture criterion is validated by comparison of load-displacement curves obtained from FEM and experimental results.

关 键 词：剪切作用 应变速率 断裂准则 应力三轴度 

分 类 号：TG115.5[金属学及工艺—物理冶金]