摘要
为研究6061铝合金在高应变率下的力学性能,利用分离式霍普金森压杆(SHPB)装置进行87组应变率为(2 000~3 400)s-1的动态压缩试验,得到应力-应变曲线。提取动态试验中试件的流动应力和塑性应变的最大值,揭示峰值应力-应变与应变率间的相关性,并根据6061铝合金的特性对Johnson-Cook本构模型进行修正。结果表明:在高应变率下,6061铝合金为应变率较敏感材料,应变率和峰值应力、应变率和峰值应变间的线性相关性较强,且修正后的JohnsonCook本构模型可以较准确地描述6061铝合金的力学性能。
In order to study the mechanical properties of 6061 aluminum alloy at high strain rate,a split Hopkinson pressure bar(SHPB)experimental device was used to carry out on 87 groups of dynamic compression experiments with strain rates in the range from 2 000 s-1to 3 400 s-1and the corresponding stress-strain curves were obtained.The maximum values of flow stress and plastic strain of the specimen in dynamic experiments were extracted,and the correlation between peak stress,peak strain and strain rate was revealed.The Johnson-Cook constitutive model was modified according to the characteristics of 6061 aluminum alloy.Results show that,at high strain rate,6061 aluminum alloy is a strain rate sensitive material,and the linear correlation between peak stress,peak strain and strain rate is strong,and the modified Johnson-Cook constitutive model can describe the mechanical properties of 6061 aluminum alloy more accurately.
引文
[1]惠旭龙,白春玉,刘小川,等.宽应变率范围下2A16-T4铝合金动态力学性能[J].爆炸与冲击,2017,37(5):871-878.
[2]张伟,魏刚,肖新科. 2A12铝合金本构关系和失效模型[J].兵工学报,2013,34(3):276-282.
[3]OLASUMBOYE A T,OWOLABI G M,ODESHI A G,et al. Dynamic behavior of AA2519-T8 aluminum alloy under high strain rate loading in compression[J]. Journal of Dynamic Behavior of Materials,2018(1):1-11.
[4]李落星,叶拓,郭鹏程,等.挤压态6061铝合金动态力学性能及微观组织演变[J].中国材料进展,2016,35(4):268-274.
[5]TIWARI S,MISHRA S,ODESHI A,et al. Evolution of texture and microstructure during high strain rate torsion of aluminium zinc magnesium copper alloy[J]. Materials Science&Engineering A,2017,683:94-102.
[6]QUAN G Z,WANG T,LI Y L,et al. Artificial neural network modeling to evaluate the dynamic flow stress of 7050 aluminum alloy[J]. Journal of Materials Engineering&Performance,2016,25(2):1-12.
[7]赵寿根,何著,杨嘉陵,等.几种航空铝材动态力学性能实验[J].北京航空航天大学学报,2007,33(8):982-985.
[8]王洪欣,查晓雄. 3004铝的动态力学性能及本构模型[J].华中科技大学学报(自然科学版),2011(5):39-42.
[9]TAN J Q,ZHAN M,LIU S,et al. A modified Johnson-Cook model for tensile flow behaviors of 7050-T7451 aluminum alloy at high strain rates[J]. Materials Science&Engineering A,2015,631(1):214-219.
[10]ZHANG Y B,YAO S,HONG X,et al. A modified johnsoncook model for 7N01 aluminum alloy under dynamic condition[J].中南大学学报(英文版),2017,24(11):2550-2555.
[11]胡时胜.霍普金森压杆技术[J].兵器材料科学与工程,1991(11):40-47.
[12]吴昊,郑靖. SHPB实验中应变片的应用和标定[J].舰船电子工程,2010,30(5):172-174.
[13]JOHNSON G R,COOK W H. A constitutive model and data for metals subjected to large strains,high strain rates and high temperatures[C]//Proceedings of the 7th International Symposium on Ballistics. The Hague,Netherlands,1983:541-548.