A phase-field crack model based on directional stress decomposition
A phase-field crack model based on directional stress decomposition
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DOI：
10.1007/s00466-018-1635-0
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发表时间：
2018-09
影响因子：
4.1
通讯作者：
C. Steinke;M. Kaliske
中科院分区：
文献类型：
--
作者：
C. Steinke;M. Kaliske
相场裂纹近似依赖于裂纹驱动应变能密度的正确定义来控制裂纹的演化和裂纹表面上的修改应力的现实模型。介绍了一种新的方法--方向分裂法，并与两种常用的公式--谱分裂法和体积偏分裂法进行了分析和比较。定向分裂的基础上的应力张量相对于裂纹方向的分解，指定的局部裂纹坐标系，裂纹驱动和持久的组件。因此，提出了一种修正的应力应变关系，以适当地模拟基本裂纹特性，并假设了一个与应力一致的裂纹驱动应变能密度。分裂最初裂纹试样的数值例子，并通过两个标准的方法得到的结果进行比较。
Phase-field crack approximation relies on the proper definition of the crack driving strain energy density to govern the crack evolution and a realistic model for the modified stresses on the crack surface. A novel approach, the directional split, is introduced, analyzed and compared to the two commonly used formulations, which are the spectral split and the volumetric–deviatoric split. The directional split is based on the decomposition of the stress tensor with respect to the crack orientation, specified by a local crack coordinate system, into crack driving and persistent components. Accordingly, a modified stress strain relation is proposed to model fundamental crack characteristics properly, and a thermodynamically consistent crack driving strain energy density is postulated. The split is applied to numerical examples of initially cracked specimens and compared to results obtained by the two standard approaches.