辽宁工程技术大学，辽宁 阜新 123000

Liaoning Technical University, Fuxin 123000, China

摘要:

提出了利用梯度塑性理论计算Ti-6Al-4V绝热剪切带的局部剪切应变新方法。绝热剪切带的最大局部塑性剪切应变依赖于临界塑性剪切应变、试样的标定长度、绝热剪切带总厚度、绝热剪切带的平均塑性剪切应变。计算表明，随着绝热剪切带总厚度的增加，绝热剪切带的最大局部塑性剪切应变以非线性方式下降。当绝热剪切带总厚度的取值接近1 mm时，尽管确定临界塑性剪切应变的方法不同，但是，绝热剪切带的最大局部塑性剪切应变的计算值差别很小。当绝热剪切带总厚度取值在0.335~1 mm之间时，绝热剪切带的最大局部塑性剪切应变的计算值位

Abstract:

A new method for assessing the local shear strain in adiabatic shear band (ASB) of Ti-6Al-4V is proposed by using of gradient-dependent plasticity. The maximum local plastic shear strain (MLPSS) in the ASB depends on the critical plastic shear strain, the gage length of Ti-6Al-4V specimen, the total thickness of the ASB and the average plastic shear strain in the ASB. Results show that the MLPSS in the ASB decreases nonlinearly with the increase of the total thickness of the ASB. When the total thickness of the ASB approaches 1mm, although the methods for determining the critical plastic shear strain are different, the calculated values for MLPSSs in the ASB almost remain unchanged. When the total thickness of the ASB is in the range of 0.335~1 mm, the calculated values for MLPSSs in the ASB are found to be in the range of the lower bound (75%) to the upper bound (350%) of the experimental results obtained by Liao and Duffy (1998).