摘要
通过单轴拉伸实验与有限元模拟相结合,研究轧制态CuAl5合金Lemaitre损伤模型参数(临界损伤值D_(c)、损伤阈值处的应变εD和断裂时的应变εR)的几何尺寸效应。结果表明,轧制态CuAl5合金损伤模型参数的确存在尺寸效应。在相同试样厚度(t)时,D_(c)随轧制压下率(R_(r))的增加而增加,在相同R_(r)下,随t的增加先减小后增加;随着R_(r)的增加或t的减小,εD和εR都呈增加趋势。此外,建立对应3种R_(r)值的损伤模型参数与t之间关系的数学模型,并通过试验验证模型预测的准确性。研究结果有利于微型零件塑性变形时断裂行为的预测。
The geometric size effects(GSEs)of Lemaitre damage model parameters(the critical damage value at rupture,D_(c),the strain at the damage threshold,ε_(D),and the strain at rupture,εR)of a rolled CuAl5 alloy were evaluated using uniaxial tensile experiments and the finite element method.The results indicated the presence of size effect on the damage model parameters of the rolled CuAl5 alloy.With an increase in reduction ratio(R_(r))at a constant thickness(t),D_(c) increased;with an increase in t at a constant R_(r),D_(c) decreased and then increased.Both ε_(D) and ε_(R) decreased with increasing R_(r)and decreasing t.New models of the relationship between the damage model parameters and t were established for the three R_(r)values.The predicted results of the models agreed with the experimental ones.These results help to accurately predict the fracture behavior of microparts during plastic forming.
作者
王秀宾
尹德良
张新平
Xiu-bin WANG;De-liang YIN;Xin-ping ZHANG(School of Materials Science and Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)
基金
the financial supports from the National Natural Science Foundation of China(No.51675283)。
