摘要
毛坯残余应力的测量以及零件的加工变形分析是航空整体结构件数控加工工艺研究的难题。应用MSC.Marc软件对某型飞机主起支撑接头的7085铝合金锻件毛坯的淬火-压缩工艺进行了数值仿真,获得了毛坯残余应力分布趋势;应用X射线衍射法与钻孔法测量了毛坯表层残余应力分布,提出了基于系数修正法的毛坯残余应力分析方法,通过最小二乘法(LSM)拟合仿真值与试验值以获得应力修正系数,并对毛坯残余应力分布的仿真结果进行修正,获得了实际毛坯的残余应力分布;由此进行了主起支撑接头缩比零件加工变形仿真与验证试验。研究结果表明:7085铝合金块状毛坯残余应力数值仿真结果与测试结果的趋势吻合,为应力修正提供了物理基础;相对于未修正的应力分布,基于修正后的应力分布仿真获得的变形结果精度提高了50%;7085-T7452铝合金的毛坯残余应力是导致主起支撑接头加工变形的主要因素。
Bulk residual stress and machining distortion of aluminum parts are major concerns in the manufacturing of aero space monolithic components.The quenching and cold compression residual stresses of main support device for landing gear made from aluminum alloy 7085 are simulated using MSC.Marc software.The surface residual stress of specimen is measured using both X-ray diffraction and hole drilling method.By comprising residual stress between simulation and measurement,residual stress simulation is corrected using least squares method （LSM）.Then the machining distortion simulation and experiment are carried out on scaled part based on the coefficient corrected residual stress.The results indicate that the stress distribution tendencies in specimen are quite similar between simulation and measurement; X-ray diffraction and hole drilling method results are found in a good agreement with each other; the analytical accuracy based on the corrected residual stress using LSM is enhanced by about 50％ on predicting machining distortion.Machining distortion can be mainly attributed to bulk residual stress within material.
出处
《航空学报》
EI
CAS
CSCD
北大核心
2014年第2期574-581,共8页
Acta Aeronautica et Astronautica Sinica
基金
国防技术基础科研项目(C1520120002
J1520130001)
高等学校博士学科点专项科研基金(20123218120025)
中央高校基本科研业务费专项资金(NS2012011)~~
关键词
残余应力
加工变形
X射线衍射
钻孔法
系数修正
residual stresses
machining distortion
X-ray diffraction
hole drilling method
coefficient modification
