Finite element model to simulate crack propagation based on local fracture stress criterion

It is important to arrest brittle crack propagation from the perspective of double integrity concept. To arrest brittle crack, structural arrest based on structural factor is attracting attention. However, the effect of structural factor is verified only by experiments and the mechanism of arrest is still unknown. The model based on a local fracture stress criterion has proposed by Shibanuma et al.. This model can reproduce the arrest behavior quantitatively only for flat plate of homogenous materials. In order to establish a general model which can evaluate structural arrest based on local fracture stress criterion, the model by FEM and nodal force release method is effective. As a preliminary investigation, we evaluated the accuracy of local stress obtained by nodal force release method. Next we made 2D model based on local fracture stress and conducted verification by comparing with exact solution. Finally, we made 3D model considering a curve of crack front. The result obtained by the model represents the behavior of crack front considering 3D effects qualitatively. It can be the base of the model to evaluate effects of structural arrest quantitatively. Copyright (C) 2016 The Authors. Published by Elsevier B.V.