Acoustic Emission Monitoring for Rolling Contact Fatigue Damage of Machined Components by Hard Turning vs. Grinding

2007 ◽  
Author(s):  
A. W. Warren ◽  
Y. B. Guo
Keyword(s):  
Shear Stress ◽  
Acoustic Emission ◽  
Fatigue Damage ◽  
Surface Integrity ◽  
Rolling Contact Fatigue ◽  
Real Life ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Second Phase ◽  
Surface Cracks

The fundamental knowledge of fatigue damage mechanism is necessary for understanding manufacturing process effects. However, the artificial defects on the test samples in traditional fatigue tests will change the surface integrity and therefore may not reflect the nature of fatigue damage. This paper studies the fatigue damage resulting from real-life rolling contact tests and finite element analysis of AISI 52100 steel and identifies the possible mechanisms for fatigue failure in the presence of process induced surface integrity. Rolling contact fatigue damage was real-time monitored using an acoustic emission (AE) sensor. Surface and subsurface fatigue damage of the samples was then characterized using optical and scanning electron microscopy (SEM) and surface profiling. The results suggest that shear stress induced Mode II crack is the dominant fatigue mechanism. Two types of subsurface cracks were observed: main cracks that propagate parallel to the surface due to subsurface shear stress induced fracture/debonding of inclusions or second phase particles. Shear stress induced surface cracks propagate at shallow angles (∼35°) from the surface. Branching cracks eventually form and connect the main crack to surface. The formation of main cracks and surface cracks may be parallel processes, and spalling occurs as a combined effect of the main, surface, and branching cracks. The relationship between AE signals and fatigue damage was been established.

Research on the Approach for the Assessment of Subsurface Rolling Contact Fatigue Damage

2013 ◽  
Vol 395-396 ◽  
pp. 845-851
Author(s):  
Xiao Feng Qin ◽  
Da Le Sun ◽  
Li Yang Xie
Keyword(s):  
Shear Stress ◽  
Friction Coefficient ◽  
Fatigue Damage ◽  
Stress Ratio ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Critical Stresses ◽  
Orthogonal Shear Stress

In this paper, the distribution of different critical stresses, which were used in previous correlation articles for the assessment of subsurface rolling contact fatigue damage, was analyzed. The rationality of orthogonal shear stress was selected as the key stress controlling the subsurface rolling contact fatigue damage was clarified. Base on the linear fatigue damage accumulative theory and the modification equation for the range of asymmetrical stress, the influence of friction on subsurface rolling contact fatigue damage was studied. The results show that the subsurface orthogonal shear stress is a completely symmetrical stress when the friction coefficient is zero, while it is an asymmetrical stress with considering the friction. The stress ratio of subsurface orthogonal shear stress and subsurface rolling contact fatigue damage is increased with the increasing of friction.

The Impact of Surface Integrity by Hard Turning vs. Grinding on Rolling Contact Fatigue

2007 ◽  
Author(s):  
A. W. Warren ◽  
Y. B. Guo
Keyword(s):  
Acoustic Emission ◽  
Surface Integrity ◽  
Hard Turning ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Polished Surface ◽  
Emission Signal ◽  
The Impact

Hard turning and grinding are finishing processes for the manufacture of precision components such as bearings, gears, and cams. However, the effects of distinct surface integrity by hard turning vs. grinding on rolling contact life are poorly understood. Four representative surface types were prepared: as-turned, as-ground, turned and polished, and ground and polished. Surface integrity was characterized by surface topography, microstructure, and micro/nanohardness. Fatigue tests were performed with an acoustic emission sensor and the signal processing software. The amplitude of acoustic emission signal is the most stable and sensitive signal to fatigue failure. The turned surface may have a longer life (>84%) than the ground one with equivalent surface finish.

Investigating the Rolling Contact Fatigue in Rails Using Finite Element Method and Cohesive Zone Approach

2018 ◽  
Author(s):  
Mohamad Ghodrati ◽  
Mehdi Ahmadian ◽  
Reza Mirzaeifar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Grain Boundaries ◽  
Fatigue Damage ◽  
Cohesive Zone ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wheel Load ◽  
Element Method

A micromechanical-based 2D framework is presented to study the rolling contact fatigue (RCF) in rail steels using finite element method. In this framework, the contact patch of rail and wheel is studied by explicitly modeling the grains and grain boundaries, to investigate the potential origin of RCF at the microstructural level. The framework incorporates Voronoi tessellation algorithm to create the microstructure geometry of rail material, and uses cohesive zone approach to simulate the behavior of grain boundaries. To study the fatigue damage caused by cyclic moving of wheels on rail, Abaqus subroutines are employed to degrade the material by increasing the number of cycles, and Jiang-Sehitoglu fatigue damage law is employed as evolution law. By applying Hertzian moving cyclic load, instead of wheel load, the effect of traction ratio and temperature change on RCF initiation and growth are studied. By considering different traction ratios (0.0 to 0.5), it is shown that increasing traction ratio significantly increases the fatigue damage. Also by increasing traction ratio, crack initiation migrates from the rail subsurface to surface. The results also show that there are no significant changes in the growth of RCF at higher temperatures, but at lower temperatures there is a measurable increase in RCF growth. This finding correlates with anecdotal information available in the rail industry about the seasonality of RCF, in which some railroads report noticing more RCF damage during the colder months.

Incipient damage detection and its propagation monitoring of rolling contact fatigue by acoustic emission

2009 ◽  
Vol 42 (6) ◽  
pp. 807-815 ◽  
Author(s):  
Ziaur Rahman ◽  
Hiroaki Ohba ◽  
Takeo Yoshioka ◽  
Takashi Yamamoto
Keyword(s):  
Acoustic Emission ◽  
Damage Detection ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact

Location of an acoustic emission source in a radially loaded deep groove ball-bearing

1998 ◽  
Vol 212 (1) ◽  
pp. 33-45 ◽  
Author(s):  
D Nélias ◽  
T Yoshioka
Keyword(s):  
Acoustic Emission ◽  
Ball Bearing ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Bearing ◽  
Rolling Contact ◽  
Fatigue Initiation ◽  
Deep Groove ◽  
Deep Groove Ball Bearing ◽  
Subsurface Defect

This paper describes a deep groove ball-bearing analysis which has been developed to simulate acoustic emission occurring during ball-bearing operation. The computer simulation is useful to clarify experimental research on rolling contact fatigue initiation using the acoustic emission technique. Results show the ability of the method to detect and to locate a subsurface defect, due to rolling contact fatigue, before the rolling bearing failure occurs. The subsurface defect can be accurately located within the inner ring of a deep groove ball-bearing operating under radial load.

Sign in / Sign up

Export Citation Format

Share Document