Keywords: fatigue, crack growth, numerical simulation, XFEM, rail, catenary contact wire, wheel-rail contact.

We present in this paper a numerical strategy to simulate the fatigue crack growth using the eXtended Finite Element Method (XFEM). The simulations are performed with the software CAST3M developed by French Atomic Energy Commission (CEA). Two applications for mechanical components of railway system are studied. The first one is the crack growth in the contact wire of the catenary system. The second one is the fatigue fracture of the rail under rolling contact loading. For the contact wire, classical Paris' law is used. The material characteristics were identified thanks to experimental tests performed in Railway Test Agency (AEF). In order to validate the numerical model and check its robustness, we performed a parametrical analysis with different crack geometries. The numerical results showed a good agreement with the experimental observations in terms of the evolution of the crack shape and its growth rate. The crack growth in the rail is more complicated than in the contact wire because of the mixed mode behaviour and the friction between crack lips. A 2D two-scale frictional contact fatigue crack model was developed within the consortium IDR2 (Initiative for Development and Research on Rails). Criteria for determining crack growth direction under multi-axial non proportional conditions and mixed mode is employed. The influence of the wheel-rail contact conditions and the initial crack orientation on the crack growth rate and direction will be analyzed.

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £65 +P&P)