应力三轴度和应变率对6063铝合金力学性能的影响及材料表征

Influence of Stress Triaxiality and Strain Rate on the Mechanics Behavior of 6063 Aluminum Alloy and Material Characterization

对6063铝合金试样在不同应力三轴度和不同应变率下进行拉伸试验,得到了该合金在这两种情况下的力学性能。研究结果表明:随着应力三轴度的减小,材料的等效弹性模量、等效屈服应力减小,但等效断裂应变增大;随着应变率逐渐增大,材料的屈服强度和断裂强度略有增大;断裂应变明显减小;抗拉强度基本不变。Johnson-cook本构模型及其断裂应变模型可以用来描述6063铝合金在不同三轴应力度和不同应变率下的本构及失效关系。通过材料表征,得出了Johnson-cook本构模型及其断裂应变模型中各个参数,为有限元(ABAQUS)模拟提供帮助。

The specimens of 6063 aluminum alloy are tensioned under different stress triaxiality and different strain rates, the mechanical properties of 6063 aluminum alloy can be drawn. It is found that the equivalent elastic modulus and equivalent yield stress decrease with stress triaxiality decreasing, but the equivalent fracture strain increases with the stress triaxiality decreasing. The yield stress （σy） and fracture stress （σf） increase slightly with the increase of strain rates, and but the fracture strain （εf） decreases obviously with the increase of strain rates, the ultimate strength （ σb ） remains constant basically. The Johnson-cook constitutive model and fracture strain model can be used to describe the constitutive and failure relations of 6063 aluminum alloy under different stress triaxiality and different strain rates. The constants of model are received to use for FEM simulation through materials characterization.