2014 Volume 2014 Pages 20140014
The objective of this study is to develop a new cohesive zone model to simulate transgranular fatigue crack propagation in polycrystalline meso-scale structures of metals. The proposed model is a combination of the interatomic potential-based cohesive crack model, which is derived from the universal binding energy relation, and the thermodynamics-based damage model, which realizes the stiffness reduction of the cohesive zone subjected to cyclic loading. To reflect the crystallographic slip behavior in cohesive cracking, we employ the standard crystal plasticity model. After the mesh-size dependency is examined, material parameters of the present model are determined with reference to a specific Paris law. Several representative numerical examples are presented to demonstrate the performance of the proposed model especially in reproducing the transgranular crack propagation with nucleation of micro-cracks under constant amplitude loading condition, and the delay of fatigue crack propagation caused by overloading.
