New Method and Application of Stress Field Calculation for Large Forgings

doi:10.3901/JME.2023.14.106

Abstract

Abstract: Large forgings are the basis of high-end equipment manufacturing industry.In the forging process, it is necessary to accurately grasp the distribution of stress field inside the blank. The forging deformation of large forgings is close to the theoretical ideal rigid-plastic material deformation model, and the relationship between the stress sphere tensor and the deformation sphere tensor is lacking. The method of calculating the internal stress field can only be solved according to the stress. In view of the theoretical and methodological difficulties in calculating the internal stress field of large forgings, based on the concept of static equilibrium stress field, the expansion second variational principle of rigid-plastic material is established and proved in detail. Applying this variational principle to calculate the stress field, due to the ease of preset static equilibrium stress field, it is not only convenient for analytical calculation and analysis, but also for loading of rigid plastic finite element method. This variational principle is used to solve the stress field inside the forging in DSF forging, and the calculation results give the technological rules in DSF forging, which provides a theoretical basis for preventing and eliminating the internal defects of large forgings.The solving process of the example reflects the superiority of the expansion second variational principle of rigid-plastic material in the analytical calculation of stress fields.

Key words: large forging, internal stress field, rigid-plastic material, variational principle, DSF forging

CLC Number:

TG316

REN Jie, GE Su, GUO Baofeng, JIN Miao. New Method and Application of Stress Field Calculation for Large Forgings[J]. Journal of Mechanical Engineering, 2023, 59(14): 106-115.

References

[1] CHAUVY C,COUDREUS L,TOUSSAINT P. Potential detrimental consequences of excessive PWHT on pressure vessel steel properties[J]. Journal of Pressure Vessel Technology-Transactions of the ASME,2012,134(2):021401-1-021401-6.
[2] NEERAJ B,ANIRUDH S. Potential detrimental consequences of stringent PWHT on pressure vessel steel forging[C]//Proceedings of 20th International Forgemasters Meeting,2017:254-263.
[3] CHANG H,LEE J,KIM N,et al Manufacturing of Ø1,000 grade large diameter round bloom and development of cost effective hot forging process using the round bloom[C]//Proceedings of 20th International Forgemasters Meeting,2017:399-407.
[4] 李昱明,洪锡军,彭颖红. 刚塑性含空洞材料变分原理的研究[J]. 上海交通大学学报,2001,35(10):1535-1538. LI Yuming,HONG Xinjun,PENG Yinghong. Study on the variation principle of rigid-plastic material containing voids[J]. Journal of Shanghai Jiao Tong University,2001,35(10):1535-1538.
[5] 祁荣胜,康冬,金淼,等. 大型锻件内部缺陷演变行为的跨尺度模拟方法[J]. 中国机械工程,2015(20):2821-2826. QI Rongsheng,KANG Dong,JIN Miao,et al. Trans-scale simulation method of evolution behavior of internal defects in large forgings[J]. China Mechanical Engineering,2015(20):2821-2826.
[6] 李学通,张沛,王敏婷,等. 大型饼类锻件镦粗夹层裂纹缺陷形成机理研究[J]. 固体力学学报,2012,33(3):273-278. LI Xuetong,ZHANG Pei,WANG Minting,et al. Study on mechanism of laminated crack defect in the upsetting process of heavy disk-shaped forgings[J]. Chinese Journal of Solid Mechanics,2012,33(3):273-278.
[7] 刘丽娟. 大锻件材料内部空洞型缺陷高温焊合过程的研究[D]. 上海:上海交通大学,2010. LIU Lijuan. Study on the bonding process of inner void defects in heavy forging at high temperature[D]. Shanghai:Shanghai Jiao Tong University,2010.
[8] 杨继东,车海伟,刘昆,等. 大型模锻压机多液压缸同步控制系统的研究[J]. 机床与液压,2015,43(14):85-87,90. YANG Jidong,Che Haiwei,LIU Kun,et al. Research on large forging presses multi-cylinder synchronous control system[J]. Machine Tool & Hydraulics,2015,43(14):85-87,90.
[9] 任运来,陈跃男,王志强,等. 基于塑性力学变分原理的大锻件镦粗变形研究[J]. 燕山大学学报,2018,42(1):22-28. REN Yunlai,CHEN Yuenan,WANG Zhiqiang,et al. On deformation of upsetting of heavy forgings based on variation principles for plastic mechanics[J]. Journal of Yanshan University,2018,42(1):22-28.
[10] 任运来,聂绍珉,牛龙江,等. 大型锻件内部空洞缺陷修复条件[J]. 机械工程学报,2008,44(2):248-252. REN Yunlai,NIE Shaomin,NIU Longjiang,et al. Healing conditions of large forgings internal voids defect[J]. Journal of Mechanical Engineering,2008,44(2):248-252.
[11] 希尔R. 塑性数学理论[M]. 北京:世界图书出版公司北京公司,2013. HILL R. The mathematical theory of plasticity[M]. Beijing:Beijing Company of World Publishing Corporation,2013.
[12] 徐秉业,陈森灿. 塑性理论简明教程[M]. 北京:清华大学出版社,1981. XU Bingye,CHEN Sencan. Concise tutorial on plasticity theory[M]. Beijing:Tsinghua University Press,1981.
[13] 鹫津久一郎. 弹性和塑性力学中的变分法[M]. 北京:科学出版社,2019. WASHIZU. Variational methods in elasticity and plasticity[M]. Beijing:Science Press,2019.
[14] QIAN W C. Second order approximation solution of nonlinear large deflection problems of Yongjiang railway bridge in Ningbo[J]. Applied Mathematics and Mechanics,2002,23(5):493-506.
[15] 任杰,孙贺磊,李加欣,等. 刚塑性材料第二变分原理的证明研究及应用[J]. 燕山大学学报,2019,43(6):497-502. REN Jie,SUN Helei,LI Jiaxin,et al. Proof and application of the second variational principle of rigid plastic materials[J]. Journal of Yanshan University,2019,43(6):497-502.
[16] 胡海昌. 广义变分原理在近似解中的合理应用[J]. 力学学报,1982(1):1-17. HU Haichang. On the rational utilization of generalized variational principles for approximate solutions[J]. Chinese Journal of Theoretical and Applied Mechanics,1982(1):1-17.
[17] LIANG Lifu,HU Haichang,LIU Shiquan.. Non-contemporaneous variations and Holder's principle[J]. Science in China Series G,2003,46(5):449-459.
[18] 张学良,张伟,温淑花,等. 结合面静摩擦因数尺度关联三维分形模型[J]. 机械工程学报,2021,57(9):127-138. ZHANG Xueliang,ZHANG Wei,WEN Shuhua,et al. Three-dimensional fractal model with scale correlation for static friction factor of joint interfaces[J]. Journal of Mechanical Engineering,2021,57(9):127-138.
[19] 王晓笋,巫世晶. 二维库伦摩擦力系统的精确解及新数值算法研究[J]. 机械工程学报,2016,52(19):110-115. WANG Xiaosun,WU Shijing. Investigation of the closed form solutions and new algorithm for two-dimensional frictional system[J]. Journal of Mechanical Engineering,2016,52(19):110-115.
[20] 俞汉清,陈金德. 金属塑性成形原理[M]. 北京:机械工业出版社,2017. YU Hanqing,CHEN Jinde. Principles of metal forming[M]. Beijing:China Machine Press,2017.
[21] 张凯锋,陆辛. 锻压手册[M]. 北京:机械工业出版社,2020. ZHANG Kaifeng,LU Xin. Forging manual[M]. Beijing:China Machine Press,2020.
[22] 梁晨,刘助柏,王连东. 新FM法拔长的临界砧宽比、临界料宽比及工艺参数研究[J]. 机械工程学报,2003,39(12):154-157. LIANG Chen,LIU Zhubai,WANG Liandong. Study on the critical values of tool width ratio and blank width ratio and the processing parameter matching of FM forging[J]. Journal of Mechanical Engineering,2003,39(12):154-157.