Combining the Lemaitre ductile fracture criterion with finite element simulation is a method widely used in predicting the cracking of a workpiece in plastic forming. In the Lemaitre criterion, the relationship between the damage value and plastic strain is supposed to be linear, which is not the case for some materials that exhibit a nonlinear relationship. In this study, the Lemaitre criterion is modified by substituting linearity for non-linearity between the damage value and plastic strain of a workpiece. The comparisons on the prediction of cone spinning cracks and splitting spinning cracks using the original and modified Lemaitre criteria show that, the prediction of the modified Lemaitre criterion is in better agreement with experiment results. The influences of deviation and mandrel rotation on the distribution and variation of damage value during cone spinning are obtained by the modified Lemaitre criterion. The results show that, the damage value is the smallest and it is most evenly distributed at zero deviation, and the damage occurrence zone under a large negative deviation is different from that under a large positive deviation. For the former, damage mainly occurs in the top zone where large tension stress exists and where there is a contact deformation zone under the action of the rollers, but for the latter damage mainly occurs in the wrinkled flange impacted by rollers. At a given feed ratio, the less the mandrel rotational speed, the slower the damage develops, and the more helpful it is for cone spinning to continue successfully.
WU Juan, ZHAN Mei, JIANG Huabing, CHEN Fei, YANG He
. A Modified Lemaitre Ductile Fracture Criterion and Its Application to Spinning Forming[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2011
, 32(7)
: 1309
-1317
.
DOI: CNKI:11-1929/V.20101228.1334.002
[1] 虞松, 陈军, 阮雪榆. 韧性断裂准则的实验和理论研究[J]. 中国机械工程, 2006, 17(19): 2049-2052. Yu Song, Chen Jun, Ruan Xueyu. Experimental and theoretical research on ductile fracture criterion[J]. China Mechanical Engineering, 2006, 17(19): 2049-2052. (in Chinese)
[2] Cockcroft M G, Latham D J. Ductility and the workability of metals[J]. Journal of the Institute of Metals, 1968, 96: 33-39.
[3] Brzzo P, Deluca B, Rendina R. A new method for the prediction of formability limit in metal sheets //Proceedings of the Seventh Biennial Conference of the International Deep Drawing Research Group.1972.
[4] Gurson A L. Continuum theory of ductile rupture by void nucleation and growth. Part 1: dash yield criteria and flow rules for porous ductile media[J]. Mechanics & Physics of Solids, 1969, 17(3): 201-217.
[5] Tvergaard V, Needleman A, Lo K K. Flow localization in the plane strain tensile test[J]. Journal of the Mechanics and Physics of Solids, 1981, 29(2): 115-142.
[6] 黄建科, 董湘怀. 金属成形中韧性断裂准则的细观损伤力学研究进展[J]. 上海交通大学学报, 2006, 40(10): 1748-1753. Huang Jianke, Dong Xianghuai. Research progress of meso damage mechanics for ductile fracture criterion in metal forming[J]. Journal of Shanghai Jiaotong University, 2006, 40(10): 1748-1753. (in Chinese)
[7] Lemaitre J. A continuous damage mechanics model for ductile fracture[J]. Journal of Engineering Materials and Technology, 1985, 107(1): 83-89.
[8] Lee S W, Pourboghrat F. Finite element simulation of the punchless piercing process with Lemaitre damage model[J]. International Journal of Mechanical Sciences, 2005, 47(11): 1756-1768.
[9] 王志刚, 李付国, 何敏. 基于损伤理论的LF2M管接头胀形工艺模拟[J]. 锻压装备与制造技术, 2009, 44(2): 92-95. Wang Zhigang, Li Fuguo, He Min. Finite element simulation of bulge forming process of the LF2M anti-rust aluminum pipe coupling based on damage development model[J]. China Metalforming Equipment & Manufacturing Technology, 2009, 44(2): 92-95. (in Chinese)
[10] 胡莉巾, 詹梅, 黄亮, 等. 采用韧性断裂准则预测分形旋压径向开裂[J]. 塑性工程学报, 2009, 16(3): 69-73. Hu Lijin, Zhan Mei, Huang Liang, et al. Prediction of radial crack of the workpiece during the splitting spinning based on ductile fracture criteria[J]. Journal of Plastic Engineering, 2009, 16(3): 69-73. (in Chinese)
[11] 范建文, 吴诗惇, 李淼泉. 杯-杆型复合挤压过程的数值模拟及其表面裂纹缺陷的预测[J]. 航空学报, 1998, 19(5): 588-591. Fan Jianwen, Wu Shichun, Li Miaoquan. Numericalsimulation and defect prediction of the cup-rod axisymmetric combined extrusion[J]. Acta Aeronautica et Astronautica Sinica, 1998, 19(5): 588-591. (in Chinese)
[12] 赵银燕, 周利. LY12CZ 薄板拉伸过程中宏/细观损伤变量间的相关性分析[J]. 航空学报, 1998, 19(1): 95-97. Zhao Yinyan, Zhou Li. Correlativity analysis of macro-and meso-damage variables in the tension of LY12CZ board specimen[J]. Acta Aeronautica et Astronautica Sinica, 1998, 19(1): 95-97. (in Chinese)
[13] 李雪春, 杨玉英, 包军, 等. 弹性模量与塑性关系的探讨[J]. 哈尔滨工业大学学报, 2000, 32(5): 54-56. Li Xuechun, Yang Yuying, Bao Jun, et al. Relationship between elastic modulus and plastic deformation[J]. Journal of Harbin Institute of Technology, 2000, 32(5): 54-56. (in Chinese)
[14] 李雪春, 杨玉英, 王永志, 等. 塑性变形对铝合金弹性模量的影响[J]. 中国有色金属学报, 2002, 12(4): 701-705. Li Xuechun, Yang Yuying, Wang Yongzhi, et al. Effect of plastic deformation on elastic modulus of aluminum alloy[J]. The Chinese Journal of Nonferrous Metals, 2002, 12(4): 701-705. (in Chinese)
[15] 郭成, 董伟, 臧来顺, 等. 弹性模量与塑性变形变化规律试验研究[J]. 锻压技术, 2008, 33(2): 116-119. Guo Cheng, Dong Wei, Zang Laishun, et al. Experimental study on variation law of Young’s modulus and plastic deformation[J]. Forging & Stamping Technology, 2008, 33(2): 116-119. (in Chinese)
[16] Yu H Y. Variation of elastic modulus during plastic deformation and its influence on spring bank[J]. Materials & Design, 2009, 30(3): 846-850.
[17] Yoshida F, Uemori T, Fujiwara K. Elastic plastic behavior of steel sheets under in-plane cyclic tension-compression at large strain[J]. International Journal of Plasticity, 2002, 18(5-6): 633-659.
[18] Morestin F, Boivin M. On the necessity of taking into account the variation in the Young modulus with plastic strain in elastic-plastic software[J]. Nuclear Engineering and Design, 1996, 162(1): 107-116.
[19] 丁玉龙. 盒形件智能化拉深的破裂预测.秦皇岛:燕山大学机械工程学院, 2005. Ding Yulong. The prediction of crack in intelligent drawing of box workpiece. Qinhuangdao: College of Mechanical Engineering, Yanshan University, 2005. (in Chinese)
[20] 黄筑平, 杨黎明. 材料的动态损伤和失效[J]. 力学进展, 1993, 23(4): 433-467. Huang Zhuping, Yang Liming. The dynamic damage and failure of material[J]. Mechanics Progress, 1993, 23(4): 433-467. (in Chinese)
[21] J. 勒迈特. 损伤力学教程[M]. 北京: 科学出版社, 1996. Lemaitre J. A course on damage mechanics[M].Beijing: Science Press, 1996. (in Chinese)
[22] 李灏. 损伤力学基础[M]. 济南: 山东科学技术出版社, 1992. Li Hao. The foundation of damage mechanics[M]. Jinan: Shandong Science & Technology Press, 1992. (in Chinese)
[23] 吴统超, 詹梅, 古创国, 等. 大型复杂薄壁壳体多道次旋压第一道次成形质量分析[J]. 材料科学与工艺(待发表). Wu Tongchao,Zhan Mei,Gu Changguo, et al. Research on the forming quality of the first pass of multi-pass spinning processing of large-sized complicated thin-walled shell[J]. Materials Science and Technology (in press). (in Chinese)
CJA