Research on the Prediction of Wrinkling Instability Characteristics in Free Bending of Tubes with Internal Mandrel Support

PAN Zhiguo; DING Tong; SHU Song; CUI Qianlin; ZHONG Qiping; GUO Xunzhong; CHENG Cheng

doi:10.3969/j.issn.1674-6457.2025.08.019

PDF(8372 KB)

Journal of Netshape Forming Engineering ›› 2025, Vol. 17 ›› Issue (8) : 180-193. DOI: 10.3969/j.issn.1674-6457.2025.08.019

Advanced Manufacturing Technology and Equipment

Research on the Prediction of Wrinkling Instability Characteristics in Free Bending of Tubes with Internal Mandrel Support

PAN Zhiguo^1,2, DING Tong¹, SHU Song², CUI Qianlin², ZHONG Qiping², GUO Xunzhong¹, CHENG Cheng^1,2,*

Author information +

History +

Abstract

The work aims to predict the wrinkling and instability characteristics of thin-walled aluminum alloy and stainless steel tubes during the three-dimensional free bending forming process under the action of internal support, through a combination of theoretical deduction, finite element simulation and physical simulation tests. Firstly, an energy prediction model for instability wrinkling under internal support was established based on the instability wrinkling energy prediction model. Secondly, geometric micro-defects under pure bending and axial compression conditions were constructed, and by applying the principle of minimum energy, the form of geometric micro-defects, buckling modes, and scaling factors were appropriately selected. Then, the accuracy of finite element simulations was validated through mechanical performance experiments on AA5052 and SS304 tubes and finite element physical simulation experiments. Finally, prediction methods for tube instability wrinkling characteristics were explored. The research combined the 0.618 search method to study the changing pattern of tubes' wrinkle sensitive areas, thereby achieving efficient and accurate prediction of instability wrinkling during the free bending forming process of the tubes, revealing the characteristics of free bending instability wrinkling. In conclusion, for AA5052 tubes, the larger the wrinkle sensitive area corresponding to the maximum wrinkling factor, the greater the likelihood of wrinkling in the bent section compared with the straight section. As the bending angle increases, the larger the sensitive area in the bend, the lower the tube's ability to resist wrinkling, and simultaneously, the greater the bending work of the tube. For SS304 tubes, at a forming ratio of 100%, the straight segment's sensitive zone is the shortest. As the tube bending process continues, the maximum axial compressive stress of the tube reaches its peak at a forming ratio of 70%, and following that, the maximum axial compressive stress decreases, thereby reducing the likelihood of wrinkling and approaching stability.

Key words

thin-walled metal tube / free bending / geometric micro-defects / wrinkling prediction

Cite this article

EndNote

Ris (Procite)

Bibtex

Download Citations

PAN Zhiguo, DING Tong, SHU Song, CUI Qianlin, ZHONG Qiping, GUO Xunzhong, CHENG Cheng. Research on the Prediction of Wrinkling Instability Characteristics in Free Bending of Tubes with Internal Mandrel Support[J]. Journal of Netshape Forming Engineering. 2025, 17(8): 180-193 https://doi.org/10.3969/j.issn.1674-6457.2025.08.019

References

[1] 张渝, 周豪, 王祥鉴, 等. 面向壁厚均匀的液压成形三通管的坯料设计方法与参数优化[J]. 精密成形工程, 2024, 16(5): 225-234.
ZHANG Y, ZHOU H, WANG X J, et al.Design Method and Parameters Optimization of Tube Blank for Hydroforming of T-Shaped Tube with Uniform Thickness[J]. Journal of Netshape Forming Engineering, 2024, 16(5): 225-234.
[2] 吴为, 周鹏, 徐鑫良, 等. 三维自由弯曲技术工艺及关键问题分析[J]. 塑性工程学报, 2023, 30(7): 1-8.
WU W, ZHOU P, XU X L, et al.Process and Key Issues Analysis of 3D Free Bending Technology[J]. Journal of Plasticity Engineering, 2023, 30(7): 1-8.
[3] 程诚, 黄祖树, 韩聪, 等. 基于三维空间轨迹控制的柔性成形技术研究进展[J]. 机械工程学报, 2022, 58(16): 160-177.
CHENG C, HUANG Z S, HAN C, et al.State-of-Art of Flexible Forming Technology Based on Three-Dimensional Trajectory Control[J]. Journal of Mechanical Engineering, 2022, 58(16): 160-177.
[4] 谢媛媛, 王华, 徐振华, 等. 基于PGWO-BP神经网络的管材自由弯曲精确成形参数预测[J]. 锻压技术, 2023, 48(3): 116-125.
XIE Y Y, WANG H, XU Z H, et al.Prediction on Precise Forming Parameters for Free Bending of Tube Based on PGWO-BP Neural Network[J]. Forging & Stamping Technology, 2023, 48(3): 116-125.
[5] 李文轩. 钛合金管材自由弯曲成形工艺参数的优化研究[D]. 西安: 西安工业大学, 2024.
LI W X.Study on the Optimization of the Free Bending Forming Process Parameters for Titanium Alloy Tubes[D]. Xi’an: Xi’an Technological University, 2024.
[6] 黎明, 魏耀光, 王永军, 等. 二维型材拉弯成形有限元模拟夹头运动轨迹设计算法[J]. 塑性工程学报, 2019, 26(2): 253-258.
LI M, WEI Y G, WANG Y J, et al.Jaw Trajectory Design Algorithm for Finite Element Simulation of 2D Profile Stretch Bending[J]. Journal of Plasticity Engineering, 2019, 26(2): 253-258.
[7] 詹梅, 杨合, 江志强. 管材弯曲成形的国内外研究现状及发展趋势[J]. 机械科学与技术, 2004, 23(12): 1509-1514.
ZHAN M, YANG H, JIANG Z Q.State of the Art of Research on Tube Bending Process[J]. Mechanical Science and Technology, 2004, 23(12): 1509-1514.
[8] 李恒, 杨合, 詹梅, 等. 薄壁件塑性成形失稳起皱的国内外研究进展[J]. 机械科学与技术, 2004, 23(7): 837-842.
LI H, YANG H, ZHAN M, et al.A Review of the Research on Wrinkling in Thin-Walled Parts Plastic Forming Processes[J]. Mechanical Science and Technology, 2004, 23(7): 837-842.
[9] 林艳. 薄壁管数控弯曲成形过程失稳起皱的数值模拟研究[D]. 西安: 西北工业大学, 2003: 5-8.
LIN Y.Numerical Simulation Research on Instability and Wrinkle Formation in the NC Bending Forming Process of Thin-Walled Tubes[D]. Xi’an: Northwestern Polytechnical University, 2003: 5-8.
[10] 李恒, 杨合, 詹梅, 等. 薄壁件塑性成形失稳起皱的国内外研究进展[J]. 机械科学与技术, 2004, 23(7): 837-842.
LI H, YANG H, ZHAN M, et al.A Review of the Research on Wrinkling in Thin-Walled Parts Plastic Forming Processes[J]. Mechanical Science and Technology, 2004, 23(7): 837-842.
[11] PEEK R.Wrinkling of Tubes in Bending from Finite Strain Three-Dimensional Continuum Theory[J]. International Journal of Solids and Structures, 2002, 39(3): 709-723.
[12] TIMOSHENKO S P.Theory of Elastic Stability[M]. New York: McGraw-Hill, 1936: 36-45.
[13] PEEK R, HILBERINK A.Axisymmetric Wrinkling of Snug-Fit Lined Pipe[J]. International Journal of Solids and Structures, 2013, 50(7/8): 1067-1077.
[14] SAFDARIAN R.Experimental and Numerical Investigation of Wrinkling and Tube Ovality in the Rotary Draw Bending Process[J]. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2019, 233(16): 5568-5584.
[15] LI H, LIU H R, LIU N, et al.Towards Sensitive Prediction of Wrinkling Instability in Sheet Metal Forming by Introducing Evolution of Triple Nonlinearity: Tube Forming[J]. International Journal of Mechanical Sciences, 2019, 161: 105054.
[16] LI H, SUN H, LIU H R, et al.Loading Conditions Constrained Wrinkling Behaviors of Thin-Walled Sheet/Tube Parts during Metal Forming[J]. Journal of Materials Processing Technology, 2021, 296: 117199.
[17] LI H, YANG H, ZHAN M, et al.A New Method to Accurately Obtain Wrinkling Limit Diagram in NC Bending Process of Thin-Walled Tube with Large Diameter under Different Loading Paths[J]. Journal of Materials Processing Technology, 2006, 177(1/2/3): 192-196.
[18] LI H, YANG H, ZHANG Z Y, et al.Multiple Instability-Constrained Tube Bending Limits[J]. Journal of Materials Processing Technology, 2014, 214(2): 445-455.
[19] SEDIGHI M, KAHNAMOUEI J T.Role of Filling Material on Defects of Thin-walled Tube Bending Process[J]. Journal of Theoretical & Applied Mechanics, 2014, 52(1): 227-233.
[20] YANG H, LIN Y.Wrinkling Analysis for Forming Limit of Tube Bending Processes[J]. Journal of Materials Processing Technology, 2004, 152(3): 363-369.
[21] 王子昂, 刘俊. 基于正交试验设计的弯管芯棒形状参数优化[J]. 塑性工程学报, 2020, 27(6): 59-65.
WANG Z A, LIU J.Shape Parameter Optimization of Mandrel for Tube Bending Based on Orthogonal Experimental Design[J]. Journal of Plasticity Engineering, 2020, 27(6): 59-65.
[22] 许小妹, 鲁世强, 方军, 等. 芯棒伸出量对0Cr21Ni6Mn9N不锈钢管数控弯曲成形质量的影响[J]. 锻压技术, 2014, 39(5): 73-77.
XU X M, LU S Q, FANG J, et al.Influence of Mandrel Extension Length on NC Bending Forming Quality of 0Cr21Ni6Mn9N Stainless Steel Tube[J]. Forging & Stamping Technology, 2014, 39(5): 73-77.
[23] CAO J, BOYCE M C.Wrinkling Behavior of Rectangular Plates under Lateral Constraint[J]. International Journal of Solids and Structures, 1997, 34(2): 153-176.
[24] GUO X Z, MA Y N, CHEN W L, et al.Simulation and Experimental Research of the Free Bending Process of a Spatial Tube[J]. Journal of Materials Processing Technology, 2018, 255: 137-149.
[25] 郭训忠, 杨秋成, 程诚, 等. 型材构件六轴自由弯曲成形机理及成形质量控制研究[J]. 航空制造技术, 2022, 65(10): 24-32.
GUO X Z, YANG Q C, CHENG C, et al.Research on Six-Axis Free Bending Forming Mechanism and Forming Quality Control of Profile Components[J]. Aeronautical Manufacturing Technology, 2022, 65(10): 24-32.
[26] GUO X Z, WEI W B, XU Y, et al.Wall Thickness Distribution of Cu-Al Bimetallic Tube Based on Free Bending Process[J]. International Journal of Mechanical Sciences, 2019, 150: 12-19.
[27] 陈清根, 徐雪峰, 王高潮, 等. 铝合金弯头冷推弯成形影响因素研究及工艺参数优化[J]. 塑性工程学报, 2015, 22(6): 40-46.
CHEN Q G, XU X F, WANG G C, et al.Influencing Factors and Parameters Optimization of Cold Push-Bending for Aluminum Alloy Elbow[J]. Journal of Plasticity Engineering, 2015, 22(6): 40-46.
[28] 孙文瑜, 徐成贤, 朱德通. 最优化方法[M]. 北京: 高等教育出版社, 2004: 107-110.
SUN W Y, XU C X, ZHU D T.Optimization Method[M]. Beijing: Higher Education Press, 2004: 107-110.