Finite element model for crack propagation in a fretting fatigue problem
Finite element model for crack propagation in a fretting fatigue problem
Autores
Director
Vanegas Useche, Libardo Vicente
Autor corporativo
Recolector de datos
Otros/Desconocido
Director audiovisual
Editor/Compilador
Editores
Pereira : Universidad Tecnológica de Pereira
Tipo de Material
Fecha
2016
Cita bibliográfica
Título de serie/ reporte/ volumen/ colección
Es Parte de
Resumen
Fretting fatigue is a type of fatigue that may occur when two surfaces are in contact and subjected to a normal force together with a small, cyclic relative motion. As it may produce failure or reduce the lifetime of a component, it is important to study and model the fretting fatigue phenomenon. The Extended Finite Element Method (XFEM), which is a variant of the finite element method, is a suitable technique to model crack growth, because the mesh of the model may be independent of the crack path and, therefore, remeshing is not necessary for crack growth. The objective of this thesis is to develop an XFEM model for crack growth under fretting fatigue conditions. The model is implemented in the software ABAQUS. The crack is represented as two-function levels using the level set method. A shifted enrichment formulation was implemented to define the contribution of the standard degrees of freedom plus the enriched contribution. The model includes a point-to-point formulation to set the contact between the crack faces. From the strain and stress results, the stress intensity factor is found using the interaction integral method, implemented in FORTRAN. Then, the crack propagation direction is determined by using the Maximum Tangential Stress (MTS) criterion and the minimum shear stress range criterion, and a new segment is added to the crack. The model was validated with the results of similar works from the literature. The predicted crack using the MTS criterion was not similar to the validation information and it was not implemented in the final model. Finally, the model was implemented using data from a Chinese railway small scale fretting fatigue test for predicting crack growth, the predicted crack using the minimum shear stress range criterion proved to be an acceptable approximation for the real crack.