• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2016, Vol. 52 ›› Issue (22): 31-37.doi: 10.3901/JME.2016.22.031

• 材料科学与工程 • 上一篇    下一篇

热冲压过程传热耦合研究*

贺斌1,2, 胡平1,2, 盈亮1,2   

  1. 1. 大连理工大学汽车工程学院 大连 116024;
    2. 大连理工大学工业装备结构分析国家重点实验室 大连 116024
  • 出版日期:2016-11-15 发布日期:2016-11-15
  • 作者简介:

    贺斌,男,1989年出生,博士研究生。主要研究方向为热冲压成形模具优化设计制造。

    E-mail:hebin_amt@foxmail.com

    胡平(通信作者),男,1956年出生,教授,博士研究生导师。主要研究方向为高强度钢板热成形、轻质金属板材温成形关键力学问题。

    E-mail:pinghu@dlut.edu.cn

  • 基金资助:
    * 国家自然科学基金重点(11272075)、中国博士后科学基金(2014M561223)和中央高校基本科研业务费专项资金(DUT16RC(4)28)资助项目; 20151225收到初稿,20160309收到修改稿;

Coupling Heat Transfer Study of Hot Stamping

HE Bin1,2, HU Ping1,2, YING Liang1,2   

  1. 1. School of Automotive Engineering, Dalian University of Technology, Dalian 116024;
    2. State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024
  • Online:2016-11-15 Published:2016-11-15

摘要:

提出一种新的思路解决热冲压过程的传热耦合模拟。板料和模具之间的界面传热系数借助圆柱形冲压试验数据并通过有限元优化反算的方法获得,将获得的界面传热系数(Interfacial heat transfer coefficient, IHTC)引入到ABAQUS的U形冲压模型中,进行单次热冲压模拟,得到一个冲压周期内模具表面任意节点的热流密度曲线。通过调用SAS程序求得模面任意节点对应的时均热流密度,将每个节点的时均热流密度和笛卡儿坐标系下的空间坐标对应关系引入到STAR-CCM+中作为模具淬火传热模拟的第二类边界条件。接着通过网格数据映射将稳态淬火模拟得到的模具温度场,水道壁表面传热系数(Film heat transfer coefficient, FHTC)和壁面冷却水温度重新导入到ABAQUS的冲压模型中进行新的热冲压模拟,此时的热冲压过程即同时实现板料-模具的界面传热和模具-水流的表面传热的稳态模拟。设计并制造仿真中使用的U形模具进行连续热冲压试验,采集特征点的稳态温度,与仿真结果进行对比。结果表明:耦合后的板料和模具的最大温度和未耦合的单次冲压相比升高近一倍,温度分布沿着水道进口向出口方向发生迁移。耦合后的板料和模具特征点温度与达到稳态的试验采集温度误差均小于10%。

关键词: 模具温度场, 耦合, 时均热流密度, 热冲压

Abstract:

A new simulation method which can couple heat transfer happened in hot stamping is proposed. The interfacial heat transfer coefficient is inverse estimated by finite element method(FEM) and optimization method which make the temperature standard deviation between simulation and cylindrical experiment reach the minimum. Then the interfacial heat transfer coefficient(IHTC) is used in a hot stamping U-HAT model to obtain the heat flux data of all nodes on the tool work surface. Statistical analysis system(SAS) program is coded to process the heat flux data and calculate the time-averaged heat flux of each node. The time-averaged heat flux of all nodes corresponding with space coordinates are introduced as Neumann condition in quenching simulation performed by STAR-CCM+. The tool temperature, channel wall temperature and nonhomogeneous film heat transfer coefficient(FHTC) form steady-state quenching simulation are mapped into the hot stamping model by ABAQUS. At the moment, the IHTC and FHTC have been coupled into the steady-state hot stamping model which not only considers the heat transfer between hot blank and cold tool but also combines the heat transfer between tool and cooling water. A U-HAT tool adopted in the simulation is designed and manufactured to perform a continuous hot stamping experiment, and the steady temperatures of several specific points on the blank and tool are collected to compare with the results from simulation. The results indicate that comparing the temperature distribution of tool and blank before coupling, the value of temperature is nearly doubled after coupling and the temperature profile is migrated along inlet to outlet. Moreover, all relative errors of steady temperature at specific points between experiment and simulation are less than 10%.

Key words: coupling, temperature field, time-averaged heat flux, hot stamping