Primal interface debonding formulation for finite strain isotropic plasticity
Primal interface debonding formulation for finite strain isotropic plasticity
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DOI：
10.1016/j.mechrescom.2020.103606
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发表时间：
2020-10
影响因子：
2.4
通讯作者：
S. Aduloju;T. Truster
中科院分区：
文献类型：
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作者：
S. Aduloju;T. Truster
开发了一个框架来模拟非线性材料的延性损伤，其塑性变形使用速率无关的经典塑性来表征。该方法依赖于自由能可以分解为弹性部分、塑性部分和损伤部分的假设。推导出满足克劳修斯-迪昂不等式形式的热力学第二定律的热力学一致方法。与塑性相关的耗散仅发生在域中，而损伤耗散则局限于界面。该方法是使用变分多尺度思想开发的，以获得类似于不连续伽辽金方法的原始公式内的界面通量的定义，这确保了在达到损坏引发标准之前界面间隙弱消失。计算塑性变形梯度和损伤变量的局部非线性问题遵循类似于经典塑性返回映射算法的增量方法。这种弹塑性损伤公式是为承受有限应变的材料开发的，它自然地适应梯形牵引分离定律 (TSL)，其形状可以改变以模拟延性界面行为或脆性界面行为。通过模拟斑贴试验和紧凑拉伸样本来评估配方的性能。
A framework is developed for modeling ductile damage of nonlinear materials whose plastic deformation is characterized using rate independent classical plasticity. This method relies on the assumption that the free energy can be decomposed into elastic, plastic and damage parts. A thermodynamically consistent method is derived which satisfies the second law of thermodynamics in the Clausius–Duhem inequality form. The dissipation associated with plasticity takes place in the domain only, while damage dissipation is localized to the interface. The method is developed using Variational Multiscale ideas to obtain definitions of the interface fluxes within a primal formulation analogous to the Discontinuous Galerkin method, which ensures weakly vanishing interface gap prior to reaching a damage initiation criterion. The local nonlinear problem to calculate both plastic deformation gradient and damage variable follows an incremental approach similar to classical plasticity return mapping algorithm. This elastoplastic damage formulation is developed for material undergoing finite strain, and it naturally accommodates a trapezoidal traction separation law (TSL) whose shape can be varied to model either ductile interface behavior or brittle interface behavior. The formulation's performance is assessed through modeling a patch test and a compact tension specimen.