大型厚壁筒体成形工艺及有限元模拟
摘要
本文采用有限元数值模拟方法，结合金属高温塑性成形的特点，详细论述了刚粘塑性有限元法的基本理论及处理方法，推导出了基于罚函数法和过应力模型的热力耦合刚粘塑性有限元列式，并建立了求解初始速度场的近似泛函，导出了求解方程。
根据上述有限元理论和处理技术，结合工程实际应用，针对厚壁筒形件的热拉深成形，建立了热力耦合刚粘塑性有限元模型，并进行了模拟计算。分析了金属应力、应变、成形载荷、温度场及颈缩缺陷与成形工艺、预制坯尺寸、模具尺寸、冷却条件的关系，提出了消除颈缩缺陷的解决方案，给出了优化的成形工艺并得出了模拟结果。
本文在厚壁圆筒件的热拉深工艺及有限元模拟方面作了一些有效的探索，可得出如下结论：
(1)一次拉深接近极限拉深系数，筒壁的等效应力超过了抗拉强度，将产生颈缩缺陷。
(2)采用温差拉深可有效提高筒壁承载能力，减少颈缩量。
(3)利用热交换区域设置边界条件，成功的建立了水冷模型，模拟结果表明，模型的建立是正确的。对类似的有限元建模有很大的指导意义。
(4)采用二次拉深的工艺方案，可增大拉深系数，减少坯料变形程度，降低其所受内应力，可望消除颈缩缺陷。
(5)凹模圆角半径或相对凹模圆角半径对筒壁壁厚变化影响很大，必须引起重视。
This article adopts the finite element numerical simulation method,and combining the shaping characteristic of metal high temperature plasticity,and had detailedly discussed just the basic theory of viscoplasticity finite element method and deals with the method,the derivation has been gone out to based on that the type is arranged in the finite element of viscoplasticity having punished the function law and the heating power coupling crossing the stress model just,and built at the beginning of finding the solution the approximate general letter of velocity field,and led out to find the solution the equation.
According to mentioned above finite element theory and the processing technology,combining the engineering application,is directed against the thick wall tin shape forging warms to draw deeply,built the heating power coupling finite element model of viscoplasticity just,the advance side by side line analog computation. Analysed metal stress and meets an emergency and load,temperature field and the neck down defect and forming technique and prefabricates base ready to be machined into a finished product size,mould size and become cool the relation of condition,and put forward eliminating the neck to contract the settlement scheme of defect,and gave out forming technique that optimizes and his to imitate at last.
Doing some active explores of hot drawing technics and FE simulation for thick cylinder in this article,and can reach the following conclusion:
(1)Once drawing to be close to the limit drawing coefficient,and the effective stress of section of wall surpassed tensile strength,and will give rise to the neck down.
(2)Adopt the difference in temperature to draw and effectively to raise a wall bearing capacity deeply,and reduces the neck down.
(3)The utilization heat exchange boundary conditions is set up successfully,and built the water-cooling model,and imitates the result to indicate that the establishment of model is correct. There is the very big guidance meaning to the similar finite element builds the pattern.
(4)Adopting two times drawing the technology scheme,and can enlarge drawing coefficient,reduce the base becoming deformed the level,and reduces the internal stress which received,hopefully eliminating the neck down.
(5)Concave die circle horn radius or relatively concave die circle horn radius is very
big to a section of thick change of the wall influence relatively must cause attaching importance to.
根据上述有限元理论和处理技术，结合工程实际应用，针对厚壁筒形件的热拉深成形，建立了热力耦合刚粘塑性有限元模型，并进行了模拟计算。分析了金属应力、应变、成形载荷、温度场及颈缩缺陷与成形工艺、预制坯尺寸、模具尺寸、冷却条件的关系，提出了消除颈缩缺陷的解决方案，给出了优化的成形工艺并得出了模拟结果。
本文在厚壁圆筒件的热拉深工艺及有限元模拟方面作了一些有效的探索，可得出如下结论：
(1)一次拉深接近极限拉深系数，筒壁的等效应力超过了抗拉强度，将产生颈缩缺陷。
(2)采用温差拉深可有效提高筒壁承载能力，减少颈缩量。
(3)利用热交换区域设置边界条件，成功的建立了水冷模型，模拟结果表明，模型的建立是正确的。对类似的有限元建模有很大的指导意义。
(4)采用二次拉深的工艺方案，可增大拉深系数，减少坯料变形程度，降低其所受内应力，可望消除颈缩缺陷。
(5)凹模圆角半径或相对凹模圆角半径对筒壁壁厚变化影响很大，必须引起重视。
This article adopts the finite element numerical simulation method,and combining the shaping characteristic of metal high temperature plasticity,and had detailedly discussed just the basic theory of viscoplasticity finite element method and deals with the method,the derivation has been gone out to based on that the type is arranged in the finite element of viscoplasticity having punished the function law and the heating power coupling crossing the stress model just,and built at the beginning of finding the solution the approximate general letter of velocity field,and led out to find the solution the equation.
According to mentioned above finite element theory and the processing technology,combining the engineering application,is directed against the thick wall tin shape forging warms to draw deeply,built the heating power coupling finite element model of viscoplasticity just,the advance side by side line analog computation. Analysed metal stress and meets an emergency and load,temperature field and the neck down defect and forming technique and prefabricates base ready to be machined into a finished product size,mould size and become cool the relation of condition,and put forward eliminating the neck to contract the settlement scheme of defect,and gave out forming technique that optimizes and his to imitate at last.
Doing some active explores of hot drawing technics and FE simulation for thick cylinder in this article,and can reach the following conclusion:
(1)Once drawing to be close to the limit drawing coefficient,and the effective stress of section of wall surpassed tensile strength,and will give rise to the neck down.
(2)Adopt the difference in temperature to draw and effectively to raise a wall bearing capacity deeply,and reduces the neck down.
(3)The utilization heat exchange boundary conditions is set up successfully,and built the water-cooling model,and imitates the result to indicate that the establishment of model is correct. There is the very big guidance meaning to the similar finite element builds the pattern.
(4)Adopting two times drawing the technology scheme,and can enlarge drawing coefficient,reduce the base becoming deformed the level,and reduces the internal stress which received,hopefully eliminating the neck down.
(5)Concave die circle horn radius or relatively concave die circle horn radius is very
big to a section of thick change of the wall influence relatively must cause attaching importance to.
引文
[1] 中物院机制所，“十五”预研立项计划书，2000
[2] 陈如欣、胡忠民，塑性有限元法及其在金属成形中的应用，重庆大学出版社，1989．12-50
[3] 汪凌云、刘静安，计算金属成形力学及应用，重庆大学出版社，1991．6
[4] 汪大年，金属塑性成形原理，机械工业出版社，1986．20-80
[5] 谢水生、王祖唐，金属塑性成形工步的有限元数值模拟，冶金工业出版社，1997．35-60
[6] 董湘怀、郑莹等，金属塑性成形计算机模拟的若干进展，金属成形工艺，2000，(1)：1-4
[7] 胡忠，塑性有限元模拟技术的最新进展，塑性工程学报，1994，(3)：3-11
[8] 周思柱，金属成形的三维有限元模拟系统的发展与展望，锻压技术，1998(4)：46-50
[9] Chenot, J.-L. Recent contributions to the finite element modelling of metal forming processes Author Affiliation, Journal of Materials Processing Technology v 34 n 1-4 Sep 1992 p 9-18 0924-0136
[10] S.Kobayashi,S.I.Oh and T.Altan,Metal Forming and the Finite Element Method,New York, Oxford University Press, 1989
[11] 孙新岭等，基于罚函数法和Backofen模型的刚粘塑性有限元列式推导，金属成形工艺，2000，(2)：4-7
[12] 章争荣、肖小亭等，轴对称体扭压成形过程的热力耦合有限元分析，金属成形工艺，1998，(3)，37-40
[13] 朱利华等，基于有限变形理论的二维弹塑性有限元模拟技术的研究，Internet
[14] Chen,C.C. and Kobayashi,S., Rigid Plastic finite element analysis of ring compression, Application of Numerical Methods to Forming Processes, ASME AMD, 1978, Vol.28, p.107
[15] Zienkiewicz'O.C., The Finite Element Msethod, third edition, McGRAN-HILL,London, 1977
[16] 张晋明，刚塑性有限元法中防止迭代发散的一种有效措施，金属成形工艺，1996，(2)：5-8
[17] Jung—Ho Cheng, Automatic Adaptive Remeshing for Finite Element Simulation of Forming Processes, Int.J.for Num. Meth. in Engr., 1988, Vol.26, P.1-18
[18] Ted D.Blacker, M.B.Stephenson, Paving: A new Approach to Automated Quadrilateral Mesh Generation, Int.J. for Num. Meth. in Enger., 1991, Vol.32, P.811-847
[19] 陈军等，锻造预成形工艺三维塑性有限元模拟，锻压机械，1997，(6)：41-44
[20] D．R．J．欧文、E．辛顿著，曾国平等译，塑性力学有限元—理论及应用，兵器工业出版社，1989．23-45
[21] J．E．艾金著，张纪刚等译，有限元法的应用与实现，科学出版社，1992．85-98
[22] 胡世杰，无凸缘筒形件的工艺计算方法，模具技术，2002，(1)：35-38
[23]姜伟之、赵时熙等，工程材料的力学性能(修订版)，北京航空航天大学出版社，2000．16-17
[24](日)太田唯南、宫内邦雄，圆筒形件的成形，机械工业出版社，1985．46-58
[25]王孝培，冲压手册(第二版)，机械工业出版社，1990
[26]熊志卿，筒形件多次拉深极限预测，中国机械工程，2001，(5)：1-4
[27]宋立彬，厚壁筒形件拉深筒壁变薄环的产生与消除，锻压机械，1999，(2)，18-20
[28]李天佑、蒋智斌，筒形件拉深过程的数值模拟，太原重型机械学院学报，1997，(3)：205-209
[29]Sawamiphakdi, K., Lahoti, G.D., Kropp, P.K., Simulation of a tube drawing process by the finite element method, Journal of Materials Processing Technology v 27 n 1-3 Aug 1991 p 179-190 0924-0136
[30]中国第一汽车集团公司编写组，机械工程材料手册—金属材料(第五版)，机械工业出版社，1998
[31]周大隽，锻压技术数据手册，机械工业出版社，1998
[32]张明元，圆筒件拉伸工艺改进，模具工业，1994，(5)：28-29
[33]鲍红忠，圆筒件热拉伸模的设计，模具工业，1995，(11)：38-40
[34]杨裕国，拉深模凹模圆角半径的选择，金属成形工艺，1996，(2)：26-28
[35]SFTC, DEFORM-2D V7.1/DEFORM-3D V3.3 User Manual, U.S.A., 2000
[36]JuiPen Tang, W.T.Wu, John Walters, DEFORMTM system structure and description, SFTC paper, 1995
[37]Matsushita, Tomiharu, Heat generation during drawing, extrusion and forging process, Research and Development Kobe Steel Engineering Reports v 48 n 1 Apr 1998 Kobe Steel Ltd p 56-59 0373-8868
[38]板金冲压工艺手册编委会，板金冲压工艺手册，国防工业出版社，1989．842-843
[2] 陈如欣、胡忠民，塑性有限元法及其在金属成形中的应用，重庆大学出版社，1989．12-50
[3] 汪凌云、刘静安，计算金属成形力学及应用，重庆大学出版社，1991．6
[4] 汪大年，金属塑性成形原理，机械工业出版社，1986．20-80
[5] 谢水生、王祖唐，金属塑性成形工步的有限元数值模拟，冶金工业出版社，1997．35-60
[6] 董湘怀、郑莹等，金属塑性成形计算机模拟的若干进展，金属成形工艺，2000，(1)：1-4
[7] 胡忠，塑性有限元模拟技术的最新进展，塑性工程学报，1994，(3)：3-11
[8] 周思柱，金属成形的三维有限元模拟系统的发展与展望，锻压技术，1998(4)：46-50
[9] Chenot, J.-L. Recent contributions to the finite element modelling of metal forming processes Author Affiliation, Journal of Materials Processing Technology v 34 n 1-4 Sep 1992 p 9-18 0924-0136
[10] S.Kobayashi,S.I.Oh and T.Altan,Metal Forming and the Finite Element Method,New York, Oxford University Press, 1989
[11] 孙新岭等，基于罚函数法和Backofen模型的刚粘塑性有限元列式推导，金属成形工艺，2000，(2)：4-7
[12] 章争荣、肖小亭等，轴对称体扭压成形过程的热力耦合有限元分析，金属成形工艺，1998，(3)，37-40
[13] 朱利华等，基于有限变形理论的二维弹塑性有限元模拟技术的研究，Internet
[14] Chen,C.C. and Kobayashi,S., Rigid Plastic finite element analysis of ring compression, Application of Numerical Methods to Forming Processes, ASME AMD, 1978, Vol.28, p.107
[15] Zienkiewicz'O.C., The Finite Element Msethod, third edition, McGRAN-HILL,London, 1977
[16] 张晋明，刚塑性有限元法中防止迭代发散的一种有效措施，金属成形工艺，1996，(2)：5-8
[17] Jung—Ho Cheng, Automatic Adaptive Remeshing for Finite Element Simulation of Forming Processes, Int.J.for Num. Meth. in Engr., 1988, Vol.26, P.1-18
[18] Ted D.Blacker, M.B.Stephenson, Paving: A new Approach to Automated Quadrilateral Mesh Generation, Int.J. for Num. Meth. in Enger., 1991, Vol.32, P.811-847
[19] 陈军等，锻造预成形工艺三维塑性有限元模拟，锻压机械，1997，(6)：41-44
[20] D．R．J．欧文、E．辛顿著，曾国平等译，塑性力学有限元—理论及应用，兵器工业出版社，1989．23-45
[21] J．E．艾金著，张纪刚等译，有限元法的应用与实现，科学出版社，1992．85-98
[22] 胡世杰，无凸缘筒形件的工艺计算方法，模具技术，2002，(1)：35-38
[23]姜伟之、赵时熙等，工程材料的力学性能(修订版)，北京航空航天大学出版社，2000．16-17
[24](日)太田唯南、宫内邦雄，圆筒形件的成形，机械工业出版社，1985．46-58
[25]王孝培，冲压手册(第二版)，机械工业出版社，1990
[26]熊志卿，筒形件多次拉深极限预测，中国机械工程，2001，(5)：1-4
[27]宋立彬，厚壁筒形件拉深筒壁变薄环的产生与消除，锻压机械，1999，(2)，18-20
[28]李天佑、蒋智斌，筒形件拉深过程的数值模拟，太原重型机械学院学报，1997，(3)：205-209
[29]Sawamiphakdi, K., Lahoti, G.D., Kropp, P.K., Simulation of a tube drawing process by the finite element method, Journal of Materials Processing Technology v 27 n 1-3 Aug 1991 p 179-190 0924-0136
[30]中国第一汽车集团公司编写组，机械工程材料手册—金属材料(第五版)，机械工业出版社，1998
[31]周大隽，锻压技术数据手册，机械工业出版社，1998
[32]张明元，圆筒件拉伸工艺改进，模具工业，1994，(5)：28-29
[33]鲍红忠，圆筒件热拉伸模的设计，模具工业，1995，(11)：38-40
[34]杨裕国，拉深模凹模圆角半径的选择，金属成形工艺，1996，(2)：26-28
[35]SFTC, DEFORM-2D V7.1/DEFORM-3D V3.3 User Manual, U.S.A., 2000
[36]JuiPen Tang, W.T.Wu, John Walters, DEFORMTM system structure and description, SFTC paper, 1995
[37]Matsushita, Tomiharu, Heat generation during drawing, extrusion and forging process, Research and Development Kobe Steel Engineering Reports v 48 n 1 Apr 1998 Kobe Steel Ltd p 56-59 0373-8868
[38]板金冲压工艺手册编委会，板金冲压工艺手册，国防工业出版社，1989．842-843