NURBS plasticity: Yield surface evolution and implicit stress integration for isotropic hardening
NURBS plasticity: Yield surface evolution and implicit stress integration for isotropic hardening
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DOI：
10.1016/j.cma.2017.05.017
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发表时间：
2017-09
影响因子：
7.2
通讯作者：
W. Coombs;Y. G. Motlagh
中科院分区：
文献类型：
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作者：
W. Coombs;Y. G. Motlagh
本文扩展了Coombs等人的非均匀有理基样条（NURBS）塑性框架。（2016）以包括屈服面的各向同性硬化。该方法允许任何光滑的各向同性屈服包络由NURBS曲面表示。本文提供的关键扩展是屈服面可以通过与材料所经历的非弹性应变水平相关联的控制点的移动来扩展或收缩。该模型集成使用一个完全隐式向后欧拉算法，约束返回路径的屈服面，并允许推导的算法一致的切线，以确保全局平衡方程的最佳收敛。这为弹塑性本构模型提供了一个强大的框架，与文献中提出的大多数模型不同，基础数值算法（和实现的代码）对于不同的屈服面保持不变。该算法的性能进行了演示，并验证，使用材料点和边界值模拟，包括平面应力，平面应变和三维的例子，不同的屈服准则。
This paper extends the non-uniform rational basis spline (NURBS) plasticity framework of Coombs et al. (2016) to include isotropic hardening of the yield surfaces. The approach allows any smooth isotropic yield envelope to be represented by a NURBS surface. The key extension provided by this paper is that the yield surface can expand or contract through the movement of control points linked to the level of inelastic straining experienced by the material. The model is integrated using a fully implicit backward Euler algorithm that constrains the return path to the yield surface and allows the derivation of the algorithmic consistent tangent to ensure optimum convergence of the global equilibrium equations. This provides a powerful framework for elasto-plastic constitutive models where, unlike the majority of models presented in the literature, the underlying numerical algorithm (and implemented code) remains unchanged for different yield surfaces. The performance of the algorithm is demonstrated, and validated, using both material point and boundary values simulations including plane stress, plane strain and three-dimensional examples for different yield criteria.