摩擦效应对三维自由弯曲过程中管材变形行为的影响规律研究  

Investigation on the influence of friction effect on tube deformation in 3D free bending process

作　　者：于波 舒送 程宗辉 张浩 程诚 郭训忠[3] 崔前林 YU Bo;SHU Song;CHENG Zonghui;ZHANG Hao;CHENG Cheng;GUO Xunzhong;CUI Qianlin(Anhui Key Laboratory of Aeronautical Equipment Measurement and Control and Reverse Engineering,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,安徽芜湖241007 [2]国营芜湖机械厂,安徽芜湖241007 [3]南京航空航天大学材料科学与技术学院,南京210016

出　　处：《兵器装备工程学报》2023年第2期203-210,共8页Journal of Ordnance Equipment Engineering

基　　金：国家自然科学基金项目(52105360);中央高校基本科研业务费项目(NS2022061)。

摘　　要：三维自由弯曲过程中管材处于少约束条件下,弯曲模与管材之间的摩擦效应对管材的自由弯曲塑性变形行为影响非常明显。为了提高管材自由弯曲成形质量,需要研究不同摩擦条件下管材弯曲半径、壁厚分布、截面畸变的演化规律。建立了考虑弯曲模对管材摩擦作用力的自由弯曲成形力学模型,采用有限元模拟和实验相结合的方法,研究了不同摩擦系数条件下管材自由弯曲过程中应力、应变分布,截面畸变率和壁厚分布的变化情况。研究结果表明,相同弯曲模偏距(U)条件下,所成形管材弯曲半径(R)随摩擦系数的减小而下降,并且弯曲弧段内侧壁厚增厚愈发明显,而弯曲弧段外侧壁厚减薄现象减弱。截面畸变率随着摩擦系数的增加呈现出先增大后逐渐平缓的趋势。因此,当采用不同材质管材和弯曲模距时,需要充分考虑摩擦效应对管材自由弯曲变形行为的影响,以获得满足质量要求的弯曲管件。In the process of three-dimensional free bending in which a tube is in a less constrained state, the friction effect between the bending die and the tube has a significant effect on the plastic deformation of tube free bending. To improve tube forming quality during the free bending process, it is necessary to study the evolution of bending radius, wall thickness distribution and cross-sectional distortion of the tube under different friction conditions. In this paper, a free bending mechanical model considering the friction force of the bending die to the tube is established. Through the finite element simulation and free bending tests, stress and strain distribution, cross-sectional distortion rate and wall thickness distribution in the free bending process of the tube with different friction coefficients are studied. The results show that, under the condition of the same bending die offset(U), the bending radius(R) of the formed pipe decreases with a decrease of the friction coefficient. In addition, the inner wall thickness of the curved arc increases significantly, while the outer wall thickness of the curved arc attenuates at a decreasing speed. With the increase of the friction coefficient, the cross-section distortion rate first increases and then gradually flattens. Therefore, when tubes of different materials and bending dies are used, it is necessary to consider the friction effect on tube free bending deformation to obtain the bending tube that meets the quality requirements.

关 键 词：自由弯曲 摩擦效应 U-R关系 壁厚分布 截面畸变 

分 类 号：TG386[金属学及工艺—金属压力加工]