Design of Fan-shaped Multi-point Flexible Stretch-bending Die Heads with FEA Verification

LIN Weihui; YANG Wenju; ZHANG Wei; ZHONG Lixin; FU Jia; LIU Ruoxuan

doi:10.3969/j.issn.1674-6457.2026.05.025

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Journal of Netshape Forming Engineering ›› 2026, Vol. 18 ›› Issue (5) : 268-276. DOI: 10.3969/j.issn.1674-6457.2026.05.025

Advanced Manufacturing Technology and Equipment

Design of Fan-shaped Multi-point Flexible Stretch-bending Die Heads with FEA Verification

LIN Weihui¹, YANG Wenju¹, ZHANG Wei¹, ZHONG Lixin¹, FU Jia^2,*, LIU Ruoxuan^1,*

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Abstract

The work aims to design a novel multi-point flexible stretch-bending die with a fan-shaped arrangement and provide theoretical support for its punch head design. A new design scheme based on the fan-shaped arrangement was proposed, following an analysis on the mechanical characteristics of dies with both parallel and fan-shaped arrays. Utilizing a conformity assumption, a theoretical model correlating the die head radius with the profile's target radius, conformity gap, and head width was developed. Concurrently, based on a deformation step difference assumption, the theoretical relationship among the conformity chord length, target radius, conformity gap, and deformation step difference was derived. Furthermore, a comprehensive die head design methodology was established to meet the requirements of various forming conditions. The finite element method (FEM) was employed to compare the forming effectiveness of the multi-point contact scheme against the conventional full-contact forming. The derived theoretical relationships provide a solid foundation for the design of the die head. Finite element analysis confirmed that the fan-shaped multi-point flexible die stretch-bending exhibited excellent forming performance, achieving a forming quality comparable to that of full-contact forming. In conclusion, the proposed fan-shaped multi-point flexible stretch-bending die demonstrates strong adaptability to diverse working conditions and shows significant application potential, underscoring its considerable engineering value.

Key words

multi-point flexible stretch-bending die / fan-shaped arrangement / die head design / conformity assumption / deformation step difference assumption / forming quality / finite element simulation

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LIN Weihui, YANG Wenju, ZHANG Wei, ZHONG Lixin, FU Jia, LIU Ruoxuan. Design of Fan-shaped Multi-point Flexible Stretch-bending Die Heads with FEA Verification[J]. Journal of Netshape Forming Engineering. 2026, 18(5): 268-276 https://doi.org/10.3969/j.issn.1674-6457.2026.05.025

References

[1] 李倩, 陶现宾, 胡德友, 等. 运载火箭薄壁锐角型材框弯曲成形工艺[J]. 精密成形工程, 2025, 17(4): 243-250.
LI Q, TAO X B, HU D Y, et al.Bending Forming Process of Thin-Walled Acute Angle Profile Frame for Carrier Rocket[J]. Journal of Netshape Forming Engineering, 2025, 17(4): 243-250.
[2] 金朝海, 刘聪, 李小强, 等. 型材拉弯工艺理论解析研究进展[J]. 锻压技术, 2021, 46(4): 21-28.
JIN C H, LIU C, LI X Q, et al.Research Progress on Theoretical Analysis for Profile in Stretch-Bending Process[J]. Forging & Stamping Technology, 2021, 46(4): 21-28.
[3] 任弼鹏. 汽车门框上条拉弯成形工艺机理研究[D]. 广州: 华南理工大学, 2019.
REN B P.Research on Mechanism for Stretch-bending of Car Door Upper Strip[D]. Guangzhou: South China University of Technology, 2019.
[4] 金妍, 杜建宁, 崔丽, 等. 变截面型材拉弯成形工艺仿真与优化[J]. 锻压技术, 2023, 48(3): 88-94.
JIN Y, DU J N, CUI L, et al.Simulation and Optimization on Stretch Bending Process for Variable Cross- Section Profile[J]. Forging & Stamping Technology, 2023, 48(3): 88-94.
[5] 吴建军, 张贺刚, 王俊彪, 等. 型材拉弯的力学与回弹分析[J]. 材料科学与工艺, 2004, 12(4): 357-359.
WU J J, ZHANG H G, WANG J B, et al.Mechanical and Spring-back Analysis for the Stretch-Bending Process of Extruded Profile[J]. Materials Science and Technology, 2004, 12(4): 357-359.
[6] 王贺, 黄霞, 孙莹, 等. 铝型材拉弯成形工艺稳健性优化[J]. 塑性工程学报, 2018, 25(3): 65-72.
WANG H, HUANG X, SUN Y, et al.Study on Process Robust Optimization for Stretch Bending of Aluminum Profile[J]. Journal of Plasticity Engineering, 2018, 25(3): 65-72.
[7] 胡晓, 尹晶晶, 汪创伟, 等. 某轿车底盘车架弯管弯制过程的起皱缺陷分析与优化[J]. 锻压技术, 2022, 47(9): 112-117.
HU X, YIN J J, WANG C W, et al.Analysis and Optimization on Wrinkling Defect in Bending Process for a Car Chassis Frame Bending Pipe[J]. Forging & Stamping Technology, 2022, 47(9): 112-117.
[8] XU Z T, QIU D K, SHAHZAMANIAN M M, et al.An Improved Springback Model Considering the Transverse Stress in Microforming[J]. International Journal of Mechanical Sciences, 2023, 241: 107947.
[9] CHEN C D, LIANG J C, LI Y, et al.Influence of Movement Tracks on the Forming Quality of Profiles Fabricated by Flexible Stretch Bending of Multi-Point Roller Dies Technology[J]. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2022, 236(8): 1102-1112.
[10] LIANG C, LUO Y D, LIANG J C, et al.Analytical Springback Assessment and Compensation in 3D Multi-Point Flexible Stretch Bending Forming[J]. The International Journal of Advanced Manufacturing Technology, 2023, 129(1): 197-206.
[11] 曾元松, 白雪飘, 吴为, 等. 柔性多点模具及其应用进展[J]. 航空制造技术, 2009, 52(10): 42-45.
ZENG Y S, BAI X P, WU W, et al.Multi-Point Flexible Die and Its Application Progress[J]. Aeronautical Manufacturing Technology, 2009, 52(10): 42-45.
[12] 于佳奇. 铝合金型材三维多点柔性拉弯成形制件质量控制的研究[D]. 长春: 吉林大学, 2018.
YU J Q.Research on the Quality Control of Three Dimensional Multi-point Flexible Stretch-bending Forming Parts for Aluminum Alloy Profile[D]. Changchun: Jilin University, 2018.
[13] 李睿. 铝型材多点拉弯模具头体与加工条件对制件成形质量影响研究[D]. 长春: 吉林大学, 2020.
LI R.Research on the Influence of Multi-point Die and Process Conditions on Forming Quality for Aluminum Profile of Multi-point Stretch-bending[D]. Changchun: Jilin University, 2020.
[14] 梁继才, 滕菲, 高嵩, 等. 柔性三维拉弯成形模具型面修正关键技术的研究[J]. 机械工程学报, 2013, 49(17): 187-192.
LIANG J C, TENG F, GAO S, et al.Key Technologies Research on the Iterative Die-Face Adjustment in the Forming Process of Flexible Three-Dimensional Stretch-Bending[J]. Journal of Mechanical Engineering, 2013, 49(17): 187-192.
[15] MA J, WELO T.Analytical Springback Assessment in Flexible Stretch Bending of Complex Shapes[J]. International Journal of Machine Tools and Manufacture, 2021, 160: 103653.
[16] LIANG J C, CHEN C D, LI Y, et al.Effect of Roller Dies on Springback Law of Profile for Flexible 3D Multi-Point Stretch Bending[J]. The International Journal of Advanced Manufacturing Technology, 2020, 108(11): 3765-3777.
[17] 陈传东. 基于辊轮式多点模具头体的柔性三维拉弯成形技术研究[D]. 长春: 吉林大学, 2022.
CHEN C D.Research on Flexible Three-Dimensional Stretch-Bending of Multi-point Roller Dies Forming Process[D]. Changchun: Jilin University, 2022.
[18] LI Y, HAN X, LIANG J C, et al.Effect of Multi-Point Roller Dies on the Forming Accuracy of Profile in Flexible 3D Stretch Bending Technology[J]. The International Journal of Advanced Manufacturing Technology, 2021, 112(3): 897-905.
[19] LI Y, LI R, LIANG C, et al.Influence of the Curvature of the Multipoint Die for Flexible Multipoint Stretch Bending on the Quality of Aluminum Profile[J]. Mathematical Problems in Engineering, 2020, 2020(1): 5960973.
[20] TENG F, LIANG J C, WANG S Q, et al.Effect of Axial Normal Stress and Bending Moment between Contact and Non-Contact Zone on Forming Accuracy for Flexible Stretch Bending Formation[J]. Metals, 2022, 12(7): 1168.
[21] CHEN C D, LIANG J C, TENG F, et al.Research on Springback Compensation Method of 3D Flexible Stretch Bending of Multi-Point Roller Dies[J]. The International Journal of Advanced Manufacturing Technology, 2021, 112(1): 563-575.
[22] SHI Z Y, LI Y, LIANG J C, et al.Effect of Forming Parameters on Profile Thinning of Flexible 3D Multi- Point Stretch Bending[J]. Metals, 2021, 11(10): 1581.
[23] CHEN C D, LIANG J C, LI Y, et al.Springback Analysis of Flexible Stretch Bending of Multi-Point Roller Dies Process for Y-Profile under Different Process Parameters[J]. Metals, 2021, 11(4): 646.
[24] GAO S, LIANG J C, LI Y, et al.Precision Forming of the 3D Curved Structure Parts in Flexible Multi-Points 3D Stretch-Bending Process[J]. The International Journal of Advanced Manufacturing Technology, 2018, 95(1): 1205-1213.
[25] GAO S, HE T G, LI Q H, et al.Research on Springback Characteristic in Flexible Multi-Points 3D Stretch- Bending Process[J]. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2022, 236(4): 440-452.
[26] LIN X F, LI Y, CAI Z Y, et al.Effect of Flexible 3D Multipoint Stretch Bending Dies on the Shape Accuracy and the Optimal Design[J]. Advances in Materials Science and Engineering, 2018, 2018(1): 1095398.