A multiscale phase field fracture approach based on the non-affine microsphere model for rubber-like materials
A multiscale phase field fracture approach based on the non-affine microsphere model for rubber-like materials
复制标题
DOI：
10.1016/j.cma.2023.115982
复制
发表时间：
2023-05
影响因子：
7.2
通讯作者：
P. K. Arunachala;Sina Abrari Vajari;M. Neuner;C. Linder
中科院分区：
文献类型：
--
作者：
P. K. Arunachala;Sina Abrari Vajari;M. Neuner;C. Linder
橡胶类材料具有广泛的应用范围，由于其独特的性能，如高拉伸性和增加的韧性。因此，用于模拟其断裂行为的计算模型对于针对故障进行设计至关重要。在这项研究中，相场断裂方法集成了多尺度聚合物模型预测弹性体的断裂行为。在微观尺度上，受损的聚合物链被建模为由许多弹性链段钉在一起。使用相场方法，链中的损伤用连续变量表示。提出了由链的键拉伸内能和熵自由能共同驱动损伤的假设，并阐述了这一假设的优点。一个框架，利用非仿射微球模型损坏的系统，提出了考虑最小化的假设未损坏的自由能，最终连接链拉伸的宏观尺度变形梯度。在宏观尺度上，推导出了一个热力学一致的公式，其中总耗散被假定为主要是由于分子键的断裂。使用单片计划，所提出的模型进行了数值实现，并将所得的三维模拟预测与现有的实验数据进行了比较。该模型的能力，定性预测复杂的裂纹路径的扩展和定量估计的整体断裂行为进行了验证。此外，长度尺度参数的预测断裂行为的影响进行了研究的非均匀系统。
Rubber-like materials have a broad scope of applications due to their unique properties like high stretchability and increased toughness. Hence, computational models for simulating their fracture behavior are paramount for designing them against failures. In this study, the phase field fracture approach is integrated with a multiscale polymer model for predicting the fracture behavior in elastomers. At the microscale, damaged polymer chains are modeled to be made up of a number of elastic chain segments pinned together. Using the phase field approach, the damage in the chains is represented using a continuous variable. Both the bond stretch internal energy and the entropic free energy of the chain are assumed to drive the damage, and the advantages of this assumption are expounded. A framework for utilizing the non-affine microsphere model for damaged systems is proposed by considering the minimization of a hypothetical undamaged free energy, ultimately connecting the chain stretch to the macroscale deformation gradient. At the macroscale, a thermodynamically consistent formulation is derived in which the total dissipation is assumed to be mainly due to the rupture of molecular bonds. Using a monolithic scheme, the proposed model is numerically implemented and the resulting three-dimensional simulation predictions are compared with existing experimental data. The capability of the model to qualitatively predict the propagation of complex crack paths and quantitatively estimate the overall fracture behavior is verified. Additionally, the effect of the length scale parameter on the predicted fracture behavior is studied for an inhomogeneous system.