一种适用于率相关晶体塑性模型的准隐式积分算法

An Semi-implicit Integration Scheme for Rate Dependent Crystal Plasticity

参考经典的切线系数法,采用向前梯度法对修正的超弹性晶体塑性模型进行本构方程积分,提出了一种新的准隐式积分算法。该算法采用基于中间构型的超弹性晶体塑性模型,无需更新晶粒取向相关的状态变量;采用修正的超弹性框架,无需进行由Green-Naghdi材料共旋引起的旋转变换。这种准隐式积分算法兼有超弹性模型和切线系数法的优点。通过对铝合金筒形件拉深的模拟表明,该晶体塑性模型能有效地预测不同初始织构产生的不同制耳现象,同时具有很高的计算效率。

A semi-implicit integration scheme for rate dependent crystal plasticity is proposed in this paper. The algorithm is similar to the tangent modulus method. A modified hyperelastic frame is adopted to circumvent the troublesome incremental objectivity encountered by the hypoelastic crystal plasticity models, especially when Green-Naghdi material co-rotational coordi- nate system （MCCS） is used, e.g. in many commercial explicit FEM software. The algorithm combines the advantages of the tangent modulus method and the hyperelastic frame. This algorithm is implemented into ABAQUS/Explicit to simulate deep drawing of aluminum alloy sheets with initial different textures. The predication of the earing profiles shows good agreement with the experimental results, and it is also found that the proposed model is computationally efficient.