中国塑料 ›› 2023, Vol. 37 ›› Issue (9): 57-63.DOI: 10.19491/j.issn.1001-9278.2023.09.009

• 加工与应用 • 上一篇    下一篇

基于Giesekus黏弹性本构的注射成型数值算法研究

花少震1,2(), 曹伟2()   

  1. 1.河南工学院机械工程学院,河南 新乡 453003
    2.郑州大学橡塑模具国家工程研究中心,郑州 450001
  • 收稿日期:2023-04-10 出版日期:2023-09-26 发布日期:2023-09-18
  • 通讯作者: 曹伟(1965—),男,教授,主要从事聚合物加工过程数值模拟研究,wcao@zzu.edu.cn
    E-mail:hsz1024@163.com;wcao@zzu.edu.cn
  • 作者简介:花少震(1988—),男,讲师,从事塑料成型数值理论与应用研究,hsz1024@163.com
  • 基金资助:
    河南省科技攻关项目(232102310413);郑州大学材料成型及模具技术教育部重点实验室开放课题(NERC202301);新乡市科技攻关项目(GG2021020)

Numerical algorithms for injection molding based on Giesekus viscoelastic model

HUA Shaozhen1,2(), CAO Wei2()   

  1. 1.School of Mechanical Engineering,Henan Institute of Technology,Xinxiang 453003,China
    2.National Engineering Research Center for Advanced Polymer Processing Technology,Zhengzhou University,Zhengzhou 450001,China
  • Received:2023-04-10 Online:2023-09-26 Published:2023-09-18
  • Contact: CAO Wei E-mail:hsz1024@163.com;wcao@zzu.edu.cn

摘要:

针对熔体的黏弹性特征,考虑熔体流动过程中的惯性作用,基于Giesekus模型建立了注射成型中熔体流动的黏弹性理论模型。将黏弹性本构方程整合为含瞬态项、对流项和源项的偏微分方程,基于有限体积法离散,提出了黏弹性本构方程的离散方法。借鉴有限元框架下的黏弹性离散分裂算法(DEVSS),发展了以有限体积法为基础的黏弹性离散分裂算法(FVM⁃DEVSS),开发了三维黏弹性流动的计算程序。用经典充分发展的4∶1收缩流验证方法的有效性,再结合充模流动实验,正确预测了熔体流动前沿、浇口压力及熔接线位置,通过光弹实验结果再次证明了本文方法的有效性。结果表明,本研究所发展的黏弹性算法可以有效表达熔体的黏性和弹性对流动压力的影响,而且能准确预测两股熔体相遇时熔接线的位置及形成过程。此外,本文黏弹性算法有效准确地计算了熔体充模过程中的流动诱导应力。

关键词: Giesekus模型, 流动诱导应力, 有限体积, 注射成型

Abstract:

The calculation of viscoelastic flow is one of the challenges in the injection molding flow analysis. With regard to the viscoelastic characteristics and taking into account the inertia effect, a viscoelastic theoretical model for the melt flow in injection molding was developed based on the Giesekus constitutive model. The viscoelastic equation was integrated into a partial differential equation containing transient, convection and source terms, and the discretization method of the viscoelastic equation was proposed on the basis of the finite volume method. Taking a reference from the discrete elastic viscous stress splitting (DEVSS) in the finite element framework, a discrete splitting algorithm (FVM⁃DEVSS) based on the finite volume method was proposed, and a computational procedure for three⁃dimensional viscoelastic flow was developed. The validity of this algorithm was verified using the classically fully developed shrinkage flow at a shrinkage ratio of 4∶1. Then, the melt flow front, gate pressure and fusion line position were correctly predicted through combing with the mold filling flow experiments. The photoelastic experimental results proved the validity of the method again in the present study. The results indicated that the developed viscoelastic algorithm could effectively express the effect of melt viscosity and elasticity on the flow pressure and accurately predict the position of a fusion line and the formation process when two melt fonts met together. In addition, the flow⁃induced stress during the melt filling process could be calculated effectively and accurately through the developed viscoelastic algorithm.

Key words: Giesekus model, flow?induced stress, finite volume method, injection molding

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