摘要
为了研究7075铝合金的动态力学性能及断裂损伤规律,采用蠕变疲劳试验机和分离式霍普金森拉杆(Split Hopkinson Tension Bar,SHTB),对7075铝合金进行了准静态拉伸试验及冲击动态拉伸试验,得到了准静态及动态拉伸应力-应变曲线。由这些曲线可知,7075铝合金的应变率效应明显,随着应变率的增加,动态增长因子近似呈线性增长。为了进一步研究7075铝合金在高应变率下的力学行为及本构模型,根据能量耗散理论,分析了材料的能量-时程曲线与耗散能规律,结果表明,耗散能随着应变率的增大而增大。随后,采用Johnson-Cook本构模型,引入基于能量耗散理论的损伤因子建立动态拉伸本构模型,并对试验曲线与理论曲线进行对比发现,两项结果拟合良好,表明该模型具有很好的适用性。
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.
作者
张艺坤
朱志武
ZHANG Yikun;ZHU Zhiwu(School of Mechanics and Aerospace Engineering,Southwest Jiaotong University,Chengdu 611756,China)
出处
《四川轻化工大学学报（自然科学版）》
CAS
2024年第1期1-8,共8页
Journal of Sichuan University of Science & Engineering(Natural Science Edition)
基金
四川省自然科学基金项目(2022NSFSC0420)。
关键词
7075铝合金
冲击
拉伸
本构模型
能量耗散
损伤
7075 aluminum alloy
impact
stretch
constitutive model
energy dissipation
damage 8
