Modeling and characterization on electroplastic effect during dynamic deformation of 5182-O aluminum alloy

The coupling effects of electrical pulse,temperature,strain rate,and strain on the flow behavior and plasticity of 5182-O aluminum alloy were investigated and characterized.The isothermal tensile test and electrically-assisted isothermal tensile test were performed at the same temperature,and three typical models were further embedded in ABAQUS/Explicit for numerical simulation to illustrate the electroplastic effect.The results show that electric pulse reduces the deformation resistance but enhances the elongation greatly.The calibration accuracy of the proposed modified Lim−Huh model for highly nonlinear and coupled dynamic hardening behavior is not much improved compared to the modified Kocks−Mecking model.Moreover,the artificial neural network model is very suitable to describe the macromechenical response of materials under the coupling effect of different variables.

WE43合金在不同应力状态下的本构关系及断裂行为表征

研究WE43合金在不同应力状态下的塑性和断裂行为。设计拉伸、压缩及剪切试样,并进行力学实验。采用数字图像相关技术对测试过程进行记录和处理。实验结果表明:WE43合金具有低的拉压非对称性,其断裂机制属于韧性断裂。基于Drucker屈服函数,采用不同的硬化规律模拟单轴拉伸和压缩下的塑性变形行为。通过数值模拟得到应力状态和断裂应变。采用Brozzo、Oh、Ko-Huh和DF2016准则对韧性断裂行为进行数值预测,并与实验结果进行对比。结果表明:采用Swift-Voce硬化定律和Drucker屈服函数能合理模拟塑性变形。DF2016断裂准则能准确预测合金在各种应力状态下的断裂行为。