Energy Dissipation Law and Dynamic Damage Constitutive Model of 7075 Aluminum Alloy
In order to study the dynamic mechanical properties and fracture damage law of 7075 aluminum alloy,quasi-static tensile tests and impact dynamic tensile tests have been conducted on 7075 aluminum alloy using Creep Fatigue Testing Machine and Split Hopkinson Tension Bar(SHTB),and quasi-static and dynamic tensile stress-strain curves are obtained.From these curves,it can be seen that the strain rate effect of 7075 aluminum alloy is significant,and the dynamic growth factor approximately increases linearly with the increasing of strain rate.In order to further study the mechanical behavior and constitutive model of 7075 aluminum alloy at high strain rates,the energy time history curve and dissipation energy law of the material are analyzed based on energy dissipation theory.The results indicate that the dissipated energy increases with the increase of strain rate.Adopting the Johnson-Cook constitutive model and introducing a damage factor based on energy dissipation theory,a dynamic tensile constitutive model is established later.Comparing the experimental curve with the theoretical curve,the two results fit well,which indicats that the model has good applicability.
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万方数据
维普
