• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2019, Vol. 55 ›› Issue (7): 217-224.doi: 10.3901/JME.2019.07.217

• 制造工艺与装备 • 上一篇    下一篇

基于直角切削的高温合金John-Cook本构参数逆向识别

陈冰, 刘卫, 罗明, 张晓腾   

  1. 西北工业大学现代设计与集成制造教育部重点实验室 西安 710072
  • 收稿日期:2018-04-11 修回日期:2018-08-24 出版日期:2019-04-05 发布日期:2019-04-05
  • 通讯作者: 陈冰(通信作者),男,1972年出生,博士,副教授,硕士研究生导师。主要研究方向为机器人柔性抛光工艺与装备,难加工材料切削加工。E-mail:Bingchen72@nwpu.edu.cn
  • 作者简介:刘卫,男,1992年出生,硕士研究生。主要研究方向为难加工材料切削加工;罗明,男,1983年生,博士,副研究员。主要研究方向为智能加工技术,加工动力学;张晓腾,男,1994年生,硕士研究生。主要研究方向为机器人抛磨轨迹优化。
  • 基金资助:
    国家自然科学基金(51575453)和国家科技重大专项(2017ZX04011001)资助项目。

Reverse Identification of John-Cook Constitutive Parameters of Superalloy Based on Orthogonal Cutting

CHEN Bing, LIU Wei, LUO Ming, ZHANG Xiaoteng   

  1. Key Laboratory of Contemporary Design and Integrated Manufacturing Technology, Ministry of Education, Northwestern Polytechnical University, Xi'an 710072
  • Received:2018-04-11 Revised:2018-08-24 Online:2019-04-05 Published:2019-04-05

摘要: 随着计算机技术的发展,有限元仿真越来越广泛应用于切削加工中参数优化、切削机理研究等领域。John-Cook (J-C)本构模型是高温合金切削仿真的基础,关系到仿真结果的准确性与可靠性。针对传统的霍普金森杆试验(Split Hopkinsonpressure bar,SHPB)获得的材料流动特性不能准确描述切削加工中材料的热塑性变形,其参数辨识的结果与实际切削状况有较大偏差的问题。提出了一种基于OXLEY切削理论和直角切削试验相结合的高温合金J-C本构参数逆向辨识方法。首先,基于不等分剪切区模型,给出了切削过程中应变、应变率、剪切区温度的分布规律;然后,针对传统车削与二维仿真模型无法直接比较的问题,设计并搭建了直角切削试验平台;最后,基于不等分剪切区模型与直角切削试验,分别计算了主剪切面流动应力的理论值和试验值,在给定本构参数约束条件下,以理论值与试验值差距最小为目标函数,通过遗传算法搜索本构参数的最优组合,实现了5个J-C本构参数(初始屈服应力A,应变强化系数B,应变率强化系数C,热软化系数m,加工硬化指数n)的最小二乘辨识。最后,将获得J-C本构参数的仿真值与试验结果进行对比,验证了逆向辨识方法的可行性与本构模型的准确性。

关键词: 本构模型, 高温合金, 逆向辨识, 直角切削

Abstract: With the development of computer technology, finite element simulation is increasingly used in the fields of parameter optimization, cutting mechanism research etc. John-Cook (J-C) constitutive model, the foundation of superalloy cutting simulation, is immediately related to the accuracy and reliability of simulation results. Centring on the problem that the material flow characteristics obtained by traditional Split Hopkinson pressure bar (SHPB) test cannot accurately describe the thermoplastic deformation of materials in cutting process and the results of parameter identification are quite different from the actual cutting conditions, a reverse identification method for J-C constitutive parameters of superalloy based on OXLEY cutting theory and orthogonal cutting test is put forward. Firstly, considering the model of unequal shear zone, the distribution regularity of strain, strain rate and shear temperature in cutting process is brought out; secondly, in view of the impossibility about directly comparing traditional turning with its two-dimensional simulation model, an orthogonal cutting experimental platform is designed and built; thirdly, based on the unequal shear zone model and the orthogonal cutting test, the theoretical and experimental values of the flow stress on the main shear plane are calculated respectively, and the least square identification of the five J-C constitutive parameters (initial yield stress A, strain strengthening coefficient B, strain rate strengthening coefficient C, thermal softening coefficient m, work hardening index n) is realized by searching the optimal combination of constitutive parameters with genetic algorithm by setting the minimum gap between the theoretical value and the experimental value as the objective function under the constraint condition of the constitutive parameters to search for its optimal combination. Eventually, the comparison between the simulation results of J-C constitutive parameters and the experimental ones is made to verify the feasibility of the reverse identification method and the accuracy of the constitutive model.

Key words: constitutive model, orthogonal cutting, reverse identification, superalloy

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