(1. 山東大學機械工程學院高效潔凈機械制造教育部重點實驗室，濟南 250061；
2. 中航工業(yè)成都飛機工業(yè)(集團)有限責任公司，成都 610092)
摘 要: 為研究7050-T7451鋁合金材料銑削后表面應力應變特征，并建立表面材料本構(gòu)關系模型，采用SSM-B4000TM型應力應變顯微探針測試系統(tǒng)對鋁合金7050-T7451材料表面進行自動球壓痕(ABI)實驗測試，獲得載荷-深度曲線，據(jù)此估算本構(gòu)關系模型中應變硬化指數(shù)(n)與屈服強度(σy)等未知參數(shù)。進而基于有限元建模(FEM)進行壓痕過程的有限元仿真分析，研究本構(gòu)關系模型中參數(shù)n與σy的變化對載荷-深度曲線的影響規(guī)律，獲得仿真載荷-深度曲線與實驗曲線誤差最小時的參數(shù)n與σy應滿足的函數(shù)關系，驗證了基于實驗本構(gòu)關系模型參數(shù)的準確性。采用該材料本構(gòu)關系模型仿真的載荷-深度曲線與實驗曲線相比，平均誤差為5.2 %。
關鍵字: 7050-T7451鋁合金；壓痕實驗；有限元仿真；本構(gòu)關系模型
（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
