Due to the difficulties in decoupling of the strain rate and stress state effects at high strain rates, very few constitutive models can account for the both effects simultaneously. Based on a novel method in the determination of the shear behaviors and constitutive modeling of materials (J. Mech. Phys. Solids 129 (2019): 184–204)), this work aims to propose a plasticity model that considers not only the stress state effect, but also the effects of strain, strain rate, and temperature on the flow stress. A series of experimental work has been conducted on the Ti-6Al-4V alloy to determine its plastic behaviors and micromechanism under different stress states (uni-axial tension, compression, and simple shear) over a large range of temperatures (93 K-1073 K) and strain rates (10⁻³ s⁻¹-6.5 × 10³ s⁻¹). Then a stress triaxiality and Lode parameter dependent plasticity model is proposed to describe the experimental results, with its performance compared systematically with the Johnson-Cook (JC) model. A much higher accuracy is shown by the present model in the characterization of the tension and compression tests. The applicability of this model is also checked by implementing it in the commercial finite element program ABAQUS/Explicit via the user material subroutine coded as VUMAT. Compared to the JC model, an obvious improvement is observed for the present model in the simulation results of both the stress waves and the flow stress curves.

由于在高应变速率下应变速率和应力状态效应之间难以解耦，因此很少有本构模型可以同时考虑这两种效应。基于一种确定材料的剪切行为和本构模型的新方法（J. Mech。Phys。Solids 129（2019）：184–204）），这项工作旨在提出一种不仅考虑应力的塑性模型。状态效应，还包括应变，应变速率和温度对流动应力的影响。已经对Ti-6Al-4V合金进行了一系列实验工作，以确定其在很大的温度范围（93 K-1073）下在不同应力状态（单轴拉伸，压缩和简单剪切）下的塑性行为和微观力学。 K）和应变率（10 ^-3 s ^-1-6.5×10 ³ s ^-1）。然后提出了应力三轴性和Lode参数相关的可塑性模型来描述实验结果，并将其性能与Johnson-Cook（JC）模型进行了系统比较。本模型在拉伸和压缩试验的表征中显示出更高的精度。通过在用户有限子程序ABAQUS / Explicit中实现该模型的适用性，也可以通过编码为VUMAT的用户材料子例程来检查该模型的适用性。与JC模型相比，在应力波和流动应力曲线的仿真结果中，本模型都具有明显的改进。