Numerical Modeling of Mode II Subsurface Crack Propagation of Through-Hardened Fe-0.5Mo-4Ni-2Cu-0.6C Steel Subjected to Rolling–Sliding Contact
No Thumbnail Available
Date
2021-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Contact fatigue is the main damage mechanism of the mechanical components that are subjected to cyclic contact stresses. Gears, bearings, and cams are among the components that may fail due to contact fatigue or subsurface crack propagation. subsurface crack propagation is affected by contact loads, contact surface frictions, the presence of asperity contacts, and initial crack direction parameters. In this research work, the effect of load, crack angle, and contact surface coefficient of friction on subsurface crack propagation and stress distribution was analyzed using a numerical approach. An extended finite element method (XFEM) was employed to study stress distribution and crack propagation. The investigation focused on the understood crack propagation using the numerical approach as it was predicted using theoretical analysis and observed during the experimental test of through-hardened steel. After inserting the initial crack at a depth (at the depth z where shear stress is maximum when we apply 622 MPa pressure) from the surface with a 2D plane strain condition. The result showed that subsurface crack propagation was dependent on the load, crack angle, and surface coefficient of friction: it grows linearly with load; decreases with increasing of surface friction coefficient; and maximum crack propagation is obtained at 45 degrees of crack angle. Again, as the applied pressure, coefficient of friction, and crack angle varies, the position of the maximum equivalent stress (nucleation site). The material for a mean pressure of 622 MPa causes cracks to propagate to 37.973 μm and when compared to the experimental crack length has a percentage of error of 5.067%. The comparison between the numerical results and the given experimental result shows reliability at a pressure of 622MPa.
Description
Keywords
Through hardened steel, Rolling-sliding contact, Subsurface crack propagation, Numerical modeling