摘要
经典的Johnson-Cook本构模型不能很好地描述钛合金在高应变率下的力学性能。作者引入S型曲线定量描述β与ε·之间的关系,对经典Johnson-Cook本构模型进行了修正,并采用遗传算法快速确定本构关系中的各个待定参数。最后以Ti-6Al-4V合金为例,采用应力增量法作出不同应变率、不同温度下的真应力-真应变曲线。数值模拟结果与文献[7]中的实验数据吻合得很好,表明修正的Johnson-Cook模型能够很好地描述Ti-6Al-4V合金在任意应变率、任意温度下的力学行为,这对预测材料在高应变率和高温下的力学行为具有重要工程意义。
The classical Johnson-Cook model can not well describe the mechanical behavior of titanium alloy under high strain rate. This paper introduced the S-curve to quantitatively describe the relationship between the function-heat transfer coefficient β and strain rate ε, and modified the classical Johnson-Cook constitutive model. The genetic algorithms was used to quickly identify the various parameters in the constitutive model. Finally, by the stress incremental approach, the true stress-true strain curves for Ti-6Al-4V alloy under different strain rates and temperatures were carried out. The numerical simulation results and experimental datas in the reference 7th can be a good match, indicating that the modified Johnson-Cook model established in this paper can well describe the mechanical behavior of Ti-6Al-4V alloy under any strain rates and temperatures. It is important to predict the mechani- cal behavior of materials at high strain rate and high temperature.
出处
《钛工业进展》
CAS
北大核心
2016年第4期17-21,共5页
Titanium Industry Progress
基金
国防重点基金项目(B1520132013-1)
