Journal of Shanghai Jiao Tong University (Science) ›› 2020, Vol. 25 ›› Issue (3): 304-314.doi: 10.1007/s12204-019-2150-y

• • 上一篇    下一篇

Optimized Design for a Combined Die with Two Stress Rings in Cold Forging Considering Thermal-Mechanical Effects

LI Zibo (李子博), ZENG Fan (曾凡), ZHAO Zhen (赵震), HU Chengliang (胡成亮)   

  1. (Institute of Forming Technology & Equipment, Shanghai Jiao Tong University, Shanghai 200030, China)
  • 出版日期:2020-06-15 发布日期:2020-05-29
  • 通讯作者: HU Chengliang (胡成亮) E-mail:clhu@sjtu.edu.cn

Optimized Design for a Combined Die with Two Stress Rings in Cold Forging Considering Thermal-Mechanical Effects

LI Zibo (李子博), ZENG Fan (曾凡), ZHAO Zhen (赵震), HU Chengliang (胡成亮)   

  1. (Institute of Forming Technology & Equipment, Shanghai Jiao Tong University, Shanghai 200030, China)
  • Online:2020-06-15 Published:2020-05-29
  • Contact: HU Chengliang (胡成亮) E-mail:clhu@sjtu.edu.cn

摘要: Stress analysis and optimization of combined die structure with two stress rings were performed. Using thermoelastic deformation, the contact pressure at the interfaces between layers was calculated. Then, theoretical expressions of stress distribution for the combined die were derived. The thermal-mechanical effect under working conditions was considered. To verify the theoretical expressions, simulation work was performed. Optimization of die design was carried out by defining radius ratio and shrink fit coefficient as optimization variables. The objective was to minimize the effective circumferential stress at the inner surface of the die insert, under the constraint that the maximum equivalent stress values of die insert and stress rings did not exceed their respective yield stresses. The Kriging model was used to describe the influence of shrink fit and die dimensions on the objective function and the maximum equivalent stress. Using a genetic algorithm, optimum parameters were found with a minimum circumferential stress of 442.9MPa under a working stress of 1 800MPa. Further analysis of five selected optimal results was carried out, and the specific design parameters of these combined dies are different under the same level of circumferential stress, and the combined die is overdesigned if the thermal effect is ignored.

关键词: cold forging, combined die, die dimension, optimization, thermal-mechanical effect, genetic algorithm

Abstract: Stress analysis and optimization of combined die structure with two stress rings were performed. Using thermoelastic deformation, the contact pressure at the interfaces between layers was calculated. Then, theoretical expressions of stress distribution for the combined die were derived. The thermal-mechanical effect under working conditions was considered. To verify the theoretical expressions, simulation work was performed. Optimization of die design was carried out by defining radius ratio and shrink fit coefficient as optimization variables. The objective was to minimize the effective circumferential stress at the inner surface of the die insert, under the constraint that the maximum equivalent stress values of die insert and stress rings did not exceed their respective yield stresses. The Kriging model was used to describe the influence of shrink fit and die dimensions on the objective function and the maximum equivalent stress. Using a genetic algorithm, optimum parameters were found with a minimum circumferential stress of 442.9MPa under a working stress of 1 800MPa. Further analysis of five selected optimal results was carried out, and the specific design parameters of these combined dies are different under the same level of circumferential stress, and the combined die is overdesigned if the thermal effect is ignored.

Key words: cold forging, combined die, die dimension, optimization, thermal-mechanical effect, genetic algorithm

中图分类号: