(1. 山东大学机械工程学院高效洁净机械制造教育部重点实验室，济南 250061；
2. 中航工业成都飞机工业(集团)有限责任公司，成都 610092)
摘 要: 为研究7050-T7451铝合金材料铣削后表面应力应变特征，并建立表面材料本构关系模型，采用SSM-B4000TM型应力应变显微探针测试系统对铝合金7050-T7451材料表面进行自动球压痕(ABI)实验测试，获得载荷-深度曲线，据此估算本构关系模型中应变硬化指数(n)与屈服强度(σy)等未知参数。进而基于有限元建模(FEM)进行压痕过程的有限元仿真分析，研究本构关系模型中参数n与σy的变化对载荷-深度曲线的影响规律，获得仿真载荷-深度曲线与实验曲线误差最小时的参数n与σy应满足的函数关系，验证了基于实验本构关系模型参数的准确性。采用该材料本构关系模型仿真的载荷-深度曲线与实验曲线相比，平均误差为5.2 %。
关键字: 7050-T7451铝合金；压痕实验；有限元仿真；本构关系模型
（1. Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education,
School of Mechanical Engineering, Shandong University, Ji’nan 250061, China;
2. AVIC Chengdu Aircraft Industrial (Group)Co., Ltd., Chengdu 610092, China）
Abstract:In order to investigate the stress-strain properties of milling surface for 7050-T7451 aluminum alloy, and also to establish the constitutive model, automated ball indentation (ABI) test was carried out on the SSM-B4000TM stress-strain microprobe system. The load-depth curve was obtained. Unknown parameters such as strain hardening exponent n and yield strength σy were obtained based on this curve. Furthermore, indentation processes were simulated based on finite element method (FEM). Accordingly, the influence rules of the changes of parameters n and σy on load-depth curve were studied. The functional relationship between parameters n and σy was obtained when the error of load-depth curve between the simulation result and experimental value is the lowest. At last, the validity of parameters n and σy in constitutive model obtained from ABI test was proved. Under this constitutive model, the average error between simulation load-depth curve and the test one is 5.2%.
Key words: 7050-T7451 aluminum alloy; indentation test; finite element simulation; constitutive model
