三维自由弯曲过程中临界偏距对管材成形精度影响  

Effect of critical eccentricity on forming accuracy of tubes in 3D free bending process

作　　者：范鑫 程宗辉 李少鑫 舒送 程诚 郭训忠[3] FAN Xin;CHENG Zonghui;LI Shaoxin;SHU Song;CHENG Cheng;GUO Xunzhong(Anhui Province Aviation Equipment Testing and Control and Reverse Engineering Laboratory,Wuhu 241007,China;State Owned Wuhu Machinery Factory,Wuhu 241007,China;College of Materials Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)

机构地区：[1]安徽省航空设备测控与逆向工程实验室,芜湖241007 [2]国营芜湖机械厂,芜湖241007 [3]南京航空航天大学材料科学与技术学院,南京210016

出　　处：《北京航空航天大学学报》2024年第1期208-215,共8页Journal of Beijing University of Aeronautics and Astronautics

基　　金：国家自然科学基金(52105360,52175328,U1937206);数字制造装备与技术国家重点实验室开放课题(DMETKF2021004);江苏省工业感知及智能制造装备工程研究中心开放基金(2021-04);江苏省“双创博士”项目(JSSCBS20210157)。

摘　　要：三维自由弯曲成形过程中弯管处于少约束状态,弯管弯曲半径的大小及轴线形状取决于相应的弯曲模偏距值。为了准确成形出预设弯管的形状,提高弯管的自由弯曲成形精度,基于弯曲模临界偏距Ue建立了弯曲模偏距U和弯管弯曲半径R(U-R)关系数学模型。采用有限元模拟与实验相结合的方法,研究了不同摩擦系数及材料参数条件下临界偏距的演化规律及其对弯管成形精度的影响。研究结果表明:引入临界偏距的U-R关系拟合结果更加符合实验结果。随着摩擦系数的增加,弯管塑性变形程度增加,临界偏距的数值降低,弯管弯曲半径减小。相比于SS304不锈钢弯管,相同工艺参数下6061铝合金弯管的弯曲半径增大,临界偏距降低。The tube is less limited during 3D free bending,and the eccentricity of the bending die determines the radius of the bend and the form of the bending axis.In order to accurately process the shape of the tube and improve the forming accuracy during the free bending process,a new free bending mechanical model was established for critical eccentricity.The influence of different friction coefficients and material parameters on the change of critical eccentricity were studied by using the finite element simulation and free bending tests.The findings have demonstrated that the experimental findings and the fitting outcomes of the U-R relationship with critical eccentricity are in a good agreement.With the increase of friction coefficient,the degree of plastic deformation of the bending tube increases,and the value of critical eccentricity and the bending radius are decreasing.Compared with SS304 tubes,the bending radius of the 6061 Al tube increases and the critical eccentricity decreases at the same process parameters.

关 键 词：管材 三维自由弯曲 弹性-塑性变形 摩擦系数 材料参数 

分 类 号：TG386[金属学及工艺—金属压力加工]