高柔性压边多点成形过程的数值模拟研究
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摘要
多点成形(Multi-point forming,简称 MPF)是金属板材三维曲面成形的一种
    柔性加工方法,其基本思想是将传统的整体模具离散化为规则排列、高度可调
    的基本体群,由基本体球头的包络面(或称基本体群成形曲面)来完成板材成
    形。多点成形采用计算机控制基本体的位移和速度,实现基本体群包络面的变
    化,从而实现板材柔性成形。它在航空航天、造船、车辆覆盖件、城市雕塑等
    诸多领域有广泛的应用前景。
    由于板类件多点成形是一个材料非线性、几何非线性的过程,分析成形件
    卸载后的回弹量,预测成形过程中可能产生的缺陷就变得十分复杂。而数值分
    析方法是金属成形中优化模具设计、预测成形缺陷及分析成形质量必不可少的
    工具,有限元技术则是各种数值方法中最为有效的方法。近几十年来,有限元
    分析在板材成形工艺分析中的应用越来越广泛。它不仅用于典型成形工艺分析
    及成形过程模拟,而且用于起皱、压痕等成形缺陷预测、成形件回弹计算以及
    用于原始坯料设计等问题。对于薄板类件多点成形过程,由于基本体和板材之
    间接触状态不断发生变化,加载条件复杂,应用动态显式有限元算法求解具有
    明显的优势。因此,本文采用动态显式有限元算法对薄板类件多点成形过程进
    行数值模拟。
    在薄板类件多点成形中,需要使用压边装置以提高成形质量。多点压机的
    压边装置是由上下各数十个压边缸组成,每一个压边缸都由独立的液压装置驱
    动,再配以合适厚度的压边圈,可以实现高柔性压边。由于使用刚性压边装置
    的多点成形易产生起皱、拉裂和压痕等成形缺陷,尤其是薄板类件的成形。这
    些缺陷严重影响工件的成形质量,制约多点成形技术的推广应用。本文借助于
    有限元数值模拟软件,对采用高柔性压边的多点成形过程进行了详细的数值模
     58
    
    
    吉林大学硕士研究生学位论文
    拟研究,并与采用刚性压边的多点成形过程进行比较,分析了成形缺陷产生的
    原因,探讨合适的工艺参数,从而消除或减轻缺陷,提高成形质量。
     本文的所做的主要工作如下:
     1) 多点成形有限元模型的建立及数值模拟关键算法和参数的研究
     根据动力松弛法的概念,利用中心差分法使动力方程求解显式化,并对接
    触和摩擦模型进行了研究;探讨了采用刚性及高柔性压边的多点成形有限元模
    型建立过程中的若干问题,如有限单元的选择、边界条件、虚拟成形速度对模
    拟结果的影响、材料模型的选择等,建立了合适的采用刚性及高柔性压边的多
    点成形有限元模型。
     2) 针对多点成形过程,对采用刚性压边和高柔性压边的多点成形过程进
    行了数值模拟对比研究
     对采用刚性压边成形时的成形缺陷如起皱、压痕和拉裂等进行了数值模
    拟。起皱是由面内压应力引起的,通常通过增加压边力来解决,但压边力增加
    容易导致直壁传力区的破裂以及压痕的出现。通过对分别采用刚性压边和高柔
    性压边的多点成形过程的模拟研究证明,采用高柔性压边装置能够有效地抑制
    各种成形缺陷,板材的拉裂力以及成形力都要比采用刚性压边成形时小。
     3) 根据多点压机柔性压边特点,对采用高柔性压边的多点成形工艺过程
    进行了数值模拟研究
     系统研究了采用高柔性压边装置的多点成形过程,对成形过程中影响压边
    圈柔性的各种工艺因素进行了模拟研究,重点探讨了压边圈厚度、板料厚度、
    不同材料参数和不同压边力等对成形质量的影响,并对不同参数时压边圈的柔
    性对板材成形质量的影响进行分析,总结出了不同工艺因素对压边圈柔性的影
    响规律,以及不同柔性程度的压边圈对板材成形质量的影响规律。
Multi-point forming (MPF) is a flexible manufacturing technology for
    three-dimensional sheet metal parts. In MPF, the conventional monolithic die is
    divided into a matrix of discrete elements. Each element’s height and velocity can
    be controlled by computer. The forming process of sheet metal is implemented by
    the contour surface of elements group. MPF has found its extensive application
    fields such as the manufacturing of the fuselage of aircraft, the hull of ship,
    covering components of vehicle, city sculpture and modern architecture etc.
     Based on the plasticity theory, the MPF of sheet metal parts is a nonlinear
    process which includes both material and geometry nonlinearity. It is difficult to
    analyse spring-back and the defects during process of MPF. Numerical analysis
    method is necessary for optimizing mould&die design, predicting defects and
    analyzing forming quality. Among the Numerical analysis methods, finite element
    analysis is the most efficient one. In recent years, it has been extensivly applied in
    technical analysis of sheet metal forming, not only in the analysing of practical
    forming process, but also predicting wrinkle, dimple, calculating the magnitude of
    spring-back, improving the raw material design, and so on. During the MPF
    process, because the contacting condition between elements and sheet metal varies
    continuously and the load condition is complex, so the dynamic explicit algorithm
    FEM is the best choice. In this thesis, dynamic explicit finite element algorithm is
    used in the simulation of the MPF process.
     In multi-point forming, a blankholder is used to improve the forming quality of
    sheet metal which is composed of dozens of hydraulic cylinders, and each of them
    is driven by its respective independent hydraulic equipment. When an appropriate
    thickness blankholder is selected in MPF, the rigid blankholder or the high flexible
    blankholder multi-point forming can be realized. But when the rigid blankholder is
    used, forming defects such as wrinkles, fractures and dimples easily occur, With the
    commercial FEA software, both the MPF process with the high flexible
    blankholder and the MPF process with the rigid blankholder have been simulated.
    The results show that MPF with high flexible blankholder can eliminate or avoid
    forming defects and improve the forming qauality.
     Main works are as following:
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    吉林大学硕士研究生学位论文
     1) Building of the finite element analysis model for MPF and research on the key
    algorithms and parameters of numerical simulation.
     Based on the concept of dynamic explicit algorithm, how to make the dynamic
    equation solution explicit utilizing the central difference method has been discussed.
    the key parameters and algorithms that have a great influence on the simulation
    precision and efficiency have been studied, such as, element formulas, material
    models, fictitious velocity and the algorithms for the spring-back analysis. And the
    finite element models for different multi-point forming principles have been built.
     2) Comparision reasearch on the numerical simulation of MPF with the high
    flexible blankholder and with the rigid blankholder
     Simulation with forming defects, such as wrinkle, dimple and crack and so on,
    have been done in MPF with the rigid blankholder. Wrinkle is arose by press stress,
    which can be eliminated by increasing BHF. But increasing BHF easily brings
    cracks and dimple at the vertical transmiting force area. By comparesion research
    on MPF with high flexible blankholder and rigid blankholder, it is clear that
    multi-point forming with high flexible blankholder can effectively restrict forming
    defects, and the crack force and the forming force during the forming are both
    smaller than that with rigid blankholder.
     3) Research on the numerical simulation of MPF with high flexible blankholder
     The multi-point forming process with high flexible blankholder has been
    systemicly studied by means of fi
引文
[1] 李明哲,中村敬一. 基本的な成形原理の检讨(板材多点成形法の研究  第 1 报).
     平成 4 年度塑性加工春季讲演会论文集,1992:519~522 
    [2] 西冈富仁雄,西牧舆,松石正克等. ュニバーサル多点プレス法による船体外板曲
     げ作业の自动化に关する研究(第 1 报:基础的研究).昭和 47 年 10 月日本造船
     学会秋季講演会论文集,132(1972):481 ̄501 
    [3] David E. Hardt,David C. Gossard.A Variable Geometry Die for Sheet Metal 
     Forming:Machine Design and Control.Proc. Jt. Autom. Control Conf. 1980:
     366~367 
    [4] D.E. Hardt,B. A. Olsen,B. T. Allison. K. Pasch.Sheet Metal Forming with 
     Discrete Die Surface.Proc:9th NAMRC,1981:275~280 
    [5] Li Mingzhe, Liu Yuhong etc. Multi-Point Forming: A Flexible Manufacturing 
     Method for a 3-D Surface Sheet. Journal of Materials Processing Technology,
     1999,87:277~280 
    [6] Li Mingzhe, Liu Chunguo, Chen Qingmin. Research on Multi-Point Forming 
     of Three-Dimensional Sheet Metal Parts. 6th International Conference on 
     Technology of Plasticity, Nuremberg,Germany,1999,1:189~194 
    [7] Li Mingzhe,Liu Chunguo,Cai Zhongyi. A Dieless Forming Technique for Sheet 
     Metal. '99 international Conference on Science and Technology, Seoul, 
     Korea,1999,7 
    [8] Li Mingzhe,Su Shizhong. The Flexible System for Manufacturing Three        
     Dimensional Curved Sheet with Technology of Multi-point forming. ICAMT’
     99 Proceedings of 1999 International Conference on Advanced Manufacturing 
     Technology,Science Press New York,ltd,1999:294~297 
    [9] Li Mingzhe,Liu Chunguo,Su Shizhong. Research on a flexible forming system 
     of sheet metal. IFAC 5th Symposium on Low Cost Automation,1998,9 
    [10] Cai Zhongyi,Li Mingzhe. Optimum path forming technique for sheet metal and 
     its realization in multi-point forming. Journal of Materials Processing 
     Technology,2001,110:136~141 
    [11] 李雪,李明哲,蔡中义. 使用弹性介质的多点成形过程数值模拟. 塑性工程学报,
     2003,10(5):20~24 
    [12] 王东哲,杨文骥,何丹农,娄臻亮,张永清. 压边圈结构对改善拉延性能的影响.
     锻压机械,2000,6 
    [13] 王东哲,娄臻亮,张永清,何丹农. 板材变压边力拉深成形方盒形件数值模拟. 上
     海交通大学学报,2001,35(10) 
     53
    
    
    吉林大学硕士研究生学位论文
    [14] 何丹农,王东哲,郑效丹,汪锐,张苇,丽均. 研究单位压边力值对板料成形性能
     的影响. 金属成形工艺,2001,19(1) 
    [15] Wang Huaibao,Xu Weili,Lin Zhongqin,Yang Yuying, Z.R. Wang. Stamping and 
     stamping simulation with a blankholder gap. Journal of Materials Processing 
     Technology,2002,120:62~67 
    [16] Ghoo.B.Y,Keum.Y.T. Expert drawbead models for sectional FEM analysis of 
     sheet metal forming. Journal of Materials Processing Technology,2000,
     105:7~16 
    [17] Chen.Fuh-Kuo,Liu.Jia-Hong. Analysis of an equivalent drawbead model for 
     the finite element simulation of a stamping processs. Journal of Materials 
     Processing Technology,1997,37:409~423 
    [18] 王东哲,何丹农,娄臻亮,张永清,程惊雷,蒋景昱. 压边力优化控制研究. 模具
     技术,2000,2 
    [19] 王东哲,吕冬,何丹农,娄臻亮,张永清,蒋景昱. 板料成形中压边力的控制理论
     研究. 锻压技术,2000,4  
    [20] Siegert K. CNC-hydraulic multipoint blank-holder system for sheet metal 
     forming presses. Ann CIRP(1993),42(1):319~322 
    [21] Leonid Shulkin, Steven W. Jansen, Mustafa A. Ahmetoglu, Gray L. Kinzel, 
     Taylan Altan. Elastic deflections of the blank holder in deep drawing of 
     sheet metal. Journal of Materials Processing Technology. 1996,59:34~
     40  
    [22] Siegert K, et al. Closed loop control of the friction force deep drawing 
     process. J. Materials Processing Technology,1997,71:126~133 
    [23] SiegertK,et al. Closed loop control system for blank holder forces in deep 
     drawing,Ann CIRP(1995),44(l):251~254 
    [24] T. Jimma,F. Sekine. Effects of Rigidity of Die and Press on Blanking Accuracy 
     of Electronic Machine Parts,Annals of the CIRP,1992,44(319) 
    [25] E.Doege,L.-E. Elend. Design and application of pliable blank holder systems 
     for sheet metal forming,Journal of Materials Processing Technology,2001,
     111:182~187 
    [26] E.Doege,eidel.H-J,Griesbach.B,Yun.J-W. Contactless on-line measurement 
     of material flow for closed loop control of deep drawing,Journal of 
     Materials Processing Technology,2002,20:95~99 
    [27] 李光耀. 三位板料成形过程的显式有限元分析,计算结构力学及其应用,1996,
     13(3):253~268 
    [28] 胡轶敏,林忠钦,张卫刚,陈关龙,秦长灯,蒋浩民,郭端权,汪承璞. 车身覆盖
     件冲压成形动态仿真的研究进展,力学进展,2000,30(2):252~271 
    [29] 郑莹,吴勇国,李尚健,李志刚,肖景荣. 板料成形数值模拟进展,塑性工程学报,
     1996,03(4) 
    [30] 杨玉英,徐伟力,金朝海等. 几种典型件成形过程的弹塑性有限元数值模拟,塑性
     工程学报,1999,6(4):22~25 
    [31] 乔端,钱仁根. 非线性有限元法及其在塑性加工中的应用,北京:冶金工业出版社,
    54
    
    
    参考文献 
     1990 
    [32] 宋天霞. 非线性结构有限元计算,武汉:华中理工大学出版社,1996 
    [33] 李尚健. 金属塑性成形过程模拟,北京:机械工业出版社,1999 
    [34] 富田佳宏著,胡平,李运兴,柳玉起译. 数值弹塑性力学,长春:吉林科学技术出
     版社,1995 
    [35] 陈如欣等. 塑性有限元法及其金属成形中的应用,重庆:重庆大学出版社,1989 
    [36] LS-NIKE3D User’s Manual. Livermore Software Technology Corporation,1995 
    [37] M.Kawka,A. Makinouchi. Shell-element formulation in the static explicit 
     FEM code for the simulation of sheet stamping.  Journal of  Materials 
     Processing Technology,1995,50(1-4):105~115 
    [38] E. Nakamachi,A. Makinouchi. Development of process simulation system for 
     autobody panel forming by FE analysis and  laser atereolithography 
     techniques,17th Biennial Congress,IDDRG Congress Proc,1992,235~242 
    [39] Ed. S. Pask, J. C. Lawrence, T. P. Dutton. A Demonstration of Numerical 
     Simulation Techniques for the Manufacture of an Automobile Oil Pan,
     Proceedings of the 3rd International Conference on High Performance 
     Computing in the Automotive Industry,Organized by Cray Research A Silicon 
     Graphics Company,Editor:M. Sheh,583~587 
    [40] ANSYS Theoretical Manual. ANSYS Corporation,2001,4 
    [41] 陈中奎,施法中. 板料冲压成形过程有限元分析中的接触搜索算法,塑性工程学报,
     2000,7(2):44~47 
    [42] 汪晨,张质良. 金属板料成形 CAE 系统及其应用,中国机械工程,1997,8(4):43~
     45 
    [43] 何君毅,林祥都. 工程结构非线性问题的数值解法,北京:国防工业出版社,1991
    [44] K. J. Bath著,傅子智译. 工程分析中的有限元法,北京:机械工业出版社,1991
    [45] 肖景容,李尚健. 塑性成形模拟理论,武汉:华中理工大学出版社,1994
    [46] 殷有泉. 固体力学非线性有限元引论,北京:北京北京大学出版社,清华大学出版
     社,1987
    [47] 龚尧南. 王寿梅结构分析中的非线性有限元素法,北京:北京航空学院出版社,1986
    [48] T. Belytschko,Neal M O. Contact-impact by the Pinball Algorithm with Penalty and
     Lagrangian Methods,Int. J. Number. Meths. Engng,1991,31:547~572
    [49] Zhong Z H. Finite Element Procedures for Contact-Impact Problems,Oxford University
     Press,1993
    [50] P.C.Galbraith,J.O.Hallquist. Shell-element formulation in LS-DYNA3D:their 
     use in the modeling of sheet-metal forming,Journal of Engineering for 
     Industry,1995,50:158~167 
    [51] 彼莱奇科,廖荣锦,默然著,庄茁译. 连续体和结构的有限元,北京:清华大学出
     版社,2002 
    [52] 汪大年. 金属塑性成形原理,北京:机械工业出版社,1982 
     55
    
    
    吉林大学硕士研究生学位论文
    [53] 李淑慧. 板材多点成形工艺的有限元分析,吉林工业大学博士学位论文,1999 
    [54] Lars Gunnarsson,Erik Schedin. Improving the properties of exterior body 
     panels in automobiles using variable blank holder force , Journal of 
     Materials Processing Technology,2001,114:89~96 
    [55] Gang Liu,Zhongqin Liu,Weili Xu,Youxia Bao. Varible blankholder force in 
     U-shaped part forming for eliminating springback error,Journal of Materials 
     Processing Technology,2001,120:259~264 
    [56] E.J. Obermeyer,S.A. Majlessi. A review of recent advances in the application 
     of blank-holder force towards improving the forming limits of sheet metal 
     parts,Journal of Materials Processing Technology,1998,75:222~234  
    [57] 余海燕,李淑慧,陈关龙,谢汐. 多点调压压边圈应力传递规律的研究,锻压装备
     与制造技术,2003,1:26~28 
    [58] 谭晶,孙胜,赵振铎. 多点位控制压边数值模拟研究,塑性工程学报,2002,9(2):
     49~52

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