当前位置: X-MOL 学术Finite Elem. Anal. Des. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
A phase field model for high-speed impact based on the updated Lagrangian formulation
Finite Elements in Analysis and Design ( IF 3.1 ) Pub Date : 2021-11-01 , DOI: 10.1016/j.finel.2021.103652
Shourong Hao 1 , Yihao Chen 1 , Jun-Bo Cheng 2 , Yongxing Shen 1
Affiliation  

High-speed impact problems usually undergo a form of highly localized plastic deformation under high strain rate with intense shock waves. In this paper, we present a coupled phase field model to simulate fracture in these situations. Our model considers the dynamic finite deformation with both strain hardening and strain rate hardening by the Johnson–Cook plasticity model. In particular, the formulation is posed in an updated Lagrangian framework and the constitutive update is realized with a return-mapping algorithm. Considering the tension–compression asymmetry, a new history variable is developed to enforce the irreversibility condition of crack propagation. The effectiveness of the proposed method is validated with a numerical example of 45 steel impact experiment along with two numerical simulations of split Hopkinson bar experiments on concrete and aluminum alloy specimens, where strong shock waves are generated. Besides, the effect of a few parameters is studied, namely, the regularization length parameter, the energy release rate, the initial impact velocity, and parameters of the Johnson–Cook model. These show the correct trend in terms of the time and extent of crack propagation.



中文翻译:

基于更新拉格朗日公式的高速撞击相场模型

高速冲击问题通常在高应变率和强烈冲击波下发生高度局部塑性变形。在本文中,我们提出了一个耦合相场模型来模拟这些情况下的断裂。我们的模型通过 Johnson-Cook 塑性模型考虑了具有应变硬化和应变率硬化的动态有限变形。特别是,该公式是在更新的拉格朗日框架中提出的,并且本构更新是通过返回映射算法实现的。考虑到拉压不对称性,开发了一个新的历史变量来强制裂纹扩展的不可逆条件。所提出方法的有效性通过 45 钢冲击实验的数值示例以及混凝土和铝合金试样上分裂霍普金森杆实验的两个数值模拟得到验证,其中产生了强烈的冲击波。此外,还研究了几个参数的影响,即正则化长度参数、能量释放率、初始冲击速度和 Johnson-Cook 模型参数。这些在裂纹扩展的时间和程度方面显示了正确的趋势。

更新日期:2021-11-02
down
wechat
bug