Transactions of Materials and Heat Treatment

Title：Influence of mandrel structure on forming quality in free bending for thin-walled tube

Authors： Guo Xunzhong Cheng Cheng Guo Jiaxin Zhang Hao Chen Hao Liu Chunmei

Unit： Nanjing University of Aeronautics and Astronautics

KeyWords： free bending thin-walled tube mandrel sectional distortion rate forming quality

ClassificationCode：TG391

year,vol(issue):pagenumber：2021,46(4):127-135

Abstract：

In order to improve the forming quality of stainless steel thin-walled tube in free bending, a mandrel is added into the tube to reduce the degree of wrinkling and sectional distortion of free bending tube. Therefore, the mechanical model with built-in mandrel of free bending was established, and the influence laws of the mandrel position, the number of balls within the mandrel and the gap between mandrel and inner wall of tube on the stress and strain distribution, the sectional distortion rate and the wall thickness distribution of stainless steel thin-walled tube in free bending process were studied by combining finite element simulation with forming experiment. The results show that the balls within the mandrel located in the deformation zone of tube support the inner wall of thin-walled tube, and under the condition of ensuring that the balls within the mandrel do not interfere with each other, the more the number of balls within the mandrel is, the greater the degree of improvement for tube forming quality is. When the gap between mandrel and tube is in a reasonable range, the thinning rate of outer wall thickness and the sectional distortion rate after free bending are smaller.

Funds：

国家自然科学基金联合基金项目（U1937206）；江苏省重点研发计划（BE2019007-2）；南工程-实验室开放基金（ASMA201903）；青年科技创新基金项目-理工军口类（NT 2020015）；江苏省自然科学基金青年基金（BK20200453）；宁波市“科技创新2025”重大专项（2020Z078）；National Natural Science Foundation of China International（Regional）Cooperation and Exchange Program（5201101342）

郭训忠（1981-），男，博士，教授 E-mail：guoxunzhong@nuaa.edu.cn 通讯作者：程诚（1991-），男，博士，讲师 E-mail：c_cheng@nuaa.edu.cn

Reference：

［1］陶杰,熊昊,万柏方,等.三维自由弯曲成形装备及其关键技术
［J］.精密成形工程,2018,10(4):1-13.

Tao J, Xiong H, Wan B F, et al. 3D free-bending forming equipment and key technology
［J］. Journal of Netshape Forming Engineering, 2018,10 (4): 1-13.

［2］华健.弯管机上弯管质量的缺陷形式及研究对策
［J］.机械设计与制造,2009，(11):202-203.

Hua J. Forms of quality defects of bending pipes made on bending machine and the solution to it
［J］. Machinery Design & Manufacture, 2009，(11): 202-203.

［3］徐勇,靳鹏飞,田亚强,等.带波纹薄壁不锈钢管的弯曲成形工艺
［J］.锻压技术,2020,45(6):71-79.

Xu Y, Jin P F, Tian Y Q, et al. Bending process of thin-walled stainless steel tube with corrugated section
［J］. Forging & Stamping Technology,2020,45(6):71-79.

［4］Xue X, Liao J, Vincze G, et al. Modelling of mandrel rotary draw bending for accurate twist springback prediction of an asymmetric thin-walled tube
［J］. Journal of Materials Processing Technology, 2015, 216:405-417.

［5］Li H, Yang H, Yan J, et al. Numerical study on deformation behaviors of thin-walled tube NC bending with large diameter and small bending radius
［J］. Computational Materials Science, 2009, 45(4):921-934.

［6］唐鼎,李大永,彭颖红.芯棒形式对铜管绕弯成形质量影响的仿真研究
［J］.中国机械工程,2006，(S1)：80-82.

Tang D, Li D Y, Peng Y H. Simulation study on the influence of mandrel form on copper tube bending quality
［J］. China Mechanical Engineering, 2006，(S1)：80-82.

［7］巫帅珍,王雅萍,朱目成,等.芯棒参数对薄壁管绕弯成形质量影响分析
［J］.西南科技大学学报,2016,31(2):99-105.

Wu S Z, Wang Y P, Zhu M C, et al. Analysis of mandrel parameters on rotary bending quality of thin-walled tube
［J］. Journal of Southwest University of science and technology, 2016,31(2): 99-105.

［8］汪鹏飞,李殿起.数控弯管机弯曲成形芯棒的研究
［J］.重型机械,2017，(4):30-33.

Wang P F, Li D Q. Research of CNC pipe bender forming mandrel
［J］. Heavy Machinery, 2017，(4): 30-33.

［9］叶福民,章威,冯露,等.薄壁圆管绕弯芯棒参数的数值模拟和实验研究
［J］.现代制造工程,2013，(10):73-78.

Ye F M, Zhang W, Feng L, et al. Numerical simulation and experimental studies of the mandrel parameters in the thin-walled pipe rotary bending
［J］. Modern Manufacturing Engineering, 2013，(10): 73-78.

［10］马燕楠. 金属管材三维自由弯曲成形研究
［D］. 南京：南京航空航天大学,2018.

Ma Y N. Research on Three Dimensional Free Bending of Metal Tube
［D］. Nanjing：Nanjing University of Aeronautics and Astronautics, 2018.

［11］刘婧瑶,唐承统,宁汝新,等.薄壁管数控弯曲成形中芯轴参数的确定
［J］.机械设计与研究,2008，24(5):70-73.

Liu J Y, Tang C T, Ning R X, et al. Ensuring the mandrel parameter in NC bending process of thin-walled tube
［J］. Mechanical Design and Research, 2008, 24(5): 70-73.

［12］Guo Q, Ma F Y, Guo X Z, et al. Influence of mandrel on the forming quality of bending L-shaped hollow parts
［J］. The International Journal of Advanced Manufacturing Technology, 2018, 95(9):4513-4522.

［13］蒋兰芳,王亚群,林姚辰,等.芯棒参数对超薄壁管数控绕弯成形质量的影响
［J］.西安交通大学学报,2020,54(4):144-154.

Jiang L F, Wang Y Q, Lin Y C, et al. Influence of mandrel parameters on NC bending quality of ultra thin wall tube
［J］. Journal of Xi′an Jiaotong University, 2020,54 (4): 144-154.

［14］程旋,魏文斌,熊昊,等.填充不同材料条件下管材三维自由弯曲变形行为研究
［J］.精密成形工程,2018,10(4):22-27.

Cheng X, Wei W B, Xiong H, et al. Research on three-dimensional free bending deformation behavior of tube filled with different materials
［J］. Journal of Netshape Forming Engineering, 2018,10 (4): 22-27.

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