Article
Mechanics
Yiping Wu, Chung Lun Pun, Pu Huang, Darrien Welsby, Peter Mutton, Anna Paradowska, Wenyi Yan
Summary: In heavy-haul railway systems, the high traction force in curved tracks accelerates rolling contact fatigue crack growth. However, there is limited research on the influence of creepage on this crack growth behavior. This paper proposes a numerical method to investigate non-proportional mixed-mode crack growth in the presence of severe creepage. Results show that lateral and spin creepages significantly affect the phase and magnitude of stress intensity factors, with spin creepage having a more detrimental effect.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Mechanical
Chenfeng Duan, Shengguan Qu, Xiongfeng Hu, Siyu Jia, Xiaoqiang Li
Summary: In this study, the combined treatment technology of shot peening and ultrasonic surface rolling was applied to improve the microhardness and residual stress of AISI 52100 steel. The results showed that the combined treatment effectively enhanced the surface properties of the alloy, although it also led to increased surface roughness. The formation of a nanocrystalline structure layer on the material surface through the combined treatment was explained, and it was found to significantly increase the fatigue life of the material.
Article
Engineering, Mechanical
Bjorn Kunzelmann, Pawel Rycerz, Yilun Xu, Nagaraj K. Arakere, Amir Kadiric
Summary: This paper investigates the application of linear elastic fracture mechanics (LEFM) principles in predicting the crack propagation of rolling contact fatigue (RCF) in machine elements such as rolling bearings and gears. Experimental tests are conducted on AISI 52100 bearing steel roller specimens to measure crack propagation rates and establish crack geometry. A numerical finite element model based on LEFM methods is developed to predict stress intensity factors (SIFs) during over-rolling, considering factors such as Hertzian contact stresses, contact friction, and crack face friction. The results show that LEFM can accurately predict the growth of RCF cracks and provide insights into the dominant propagation mode and the effects of crack face friction. The findings contribute to the development of tools for predicting the remaining useful life of machine components, enhancing the reliability of mechanical systems.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Jihwi Kim, Michael R. Hill
Summary: This study develops a method to predict crack face contact under linear elastic conditions in a residual stress-bearing body. The method applies the weight function to compute a system of linear equations that can determine crack face contact pressure. The method is validated against the finite element method and shows good agreement in predicting crack face contact and the effects of residual stress on fatigue crack growth.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Abdul Haseeb Afridi, Hongtao Zhu, Eduardo Tovar Camacho, Guanyu Deng, Huijun Li
Summary: Rolling contact fatigue (RCF) crack is a dominant form of damage on rail surfaces caused by repeated contact with wheels. If left untreated, RCF defects such as squats and head checks can lead to rail fractures. Accurately predicting the damage under different operational conditions is crucial. A two-stage simulation strategy was proposed, investigating the mechanisms of RCF-induced cracks on rails through dynamic FEM for wheel-rail interaction and coupled static FEM/BEM for crack growth. The study found two critical wheel positions for crack propagation during wheel approach and departure from pre-existing cracks.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Engineering, Mechanical
Yoshikazu Nakai, Daiki Shiozawa, Shoichi Kikuchi, Takashi Nishina, Hiroshi Kobayashi, Masanori Kurahashi, Taizo Makino, Yutaka Neishi
Summary: Rolling contact fatigue tests were conducted to investigate the effect of inclusion orientation on the fatigue life, and the results were compared with those of specimens containing stringer-shaped inclusions. The study found that cracks first formed on the rolling surface and then propagated in the depth direction, leading to flaking. The flaking life of specimens with spheroidal inclusions was longer than that of specimens with stringer-shaped inclusions, and the initiation and propagation lives of cracks were influenced by the shape and size of inclusions.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Engineering, Mechanical
Mads Aursand, Bjorn H. Skallerud
Summary: This study investigates stress intensity factors for surface cracks with different geometries on curved round bars under various mode I stress distributions. Semi-analytical solutions for SIF at any point on the crack front are developed using finite element analysis and linear elastic fracture mechanics methods. Results demonstrate up to 8% difference in SIF values for cracks in curved bars compared to straight bars, with effects of relative bar curvature on numerical results being shown. The estimation of SIFs for cracks in a complex residual stress field is also demonstrated using a cubic polynomial stress approximation with an offshore mooring chain model as a case study.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2021)
Article
Materials Science, Multidisciplinary
D. Mayweg, L. Morsdorf, X. Wu, M. Herbig
Summary: The white etching crack (WEC) phenomena in high carbon steels affect bearings, and research shows that it is associated with the carbon element. Analyzing the carbon content and distribution in 100Cr6 bearings can provide insights into the formation mechanism of white etching cracks.
Article
Engineering, Mechanical
Gopalakrishnan Ravi, Wim De Waele, Ksenija Nikolic, Roumen Petrov, Stijn Hertel
Summary: Bearing failure can occur in various machinery and is often caused by rolling contact fatigue (RCF) triggered by damage initiation at non-metallic inclusions (NMI's). This study focuses on numerically investigating the impact of NMI features and bonding with the steel matrix on damage initiation lifetime. Simulation results indicate an immediate debonding at the matrix-inclusion interface followed by accelerated crack initiation. The depth for damage initiation shifts towards the surface with increasing friction coefficient between roller and raceway, and larger inclusions demonstrate earlier damage initiation.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
Jee-Hyun Kang, Jungwoong Kim, Jun-Yun Kang, Soon-Woo Kwon, Min-Woo Kang, Seung Hyun Hong
Summary: This study provides an in-depth characterization of the formation mechanism of the dark-etching region (DER) caused by rolling contact fatigue in bearing steel. The results reveal that the accumulation of plastic flow and dynamic recrystallization contribute to the hardness reduction and etching behavior, which may lead to spalling of the bearing.
Article
Engineering, Mechanical
S. Y. Zhang, Q. Y. Liu, H. H. Ding, M. Spiryagin, Q. Wu, L. C. Guo, W. J. Wang
Summary: A model for predicting the initiation of cracking in the contact area between wheels and rails was developed. The study investigated the effects of surface defects on crack initiation and found that cracks first appeared at the trailing edge of the defect before moving to the leading edge.
Article
Engineering, Mechanical
Jun-peng Li, Yu Zhou, Zhong-ning Cheng, Chi Wang, Zhi-Yi Weng
Summary: During rolling contact fatigue (RCF) and wear on the rail surface, the microscopic characteristics of the rail material change. RCF and wear alternate to dominate the rail disc surface at the microscale, with increasing micro-hardness leading to a decrease in relative wear rate and an increase in roughness and number of RCF cracks.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Chemistry, Physical
Ruipeng Gao, Mengmeng Liu, Bing Wang, Yiran Wang, Wei Shao
Summary: The study found that as the rail crack length increases, the position where the crack propagates by mode I shifts from the inner edge of the wheel-rail contact spot to the outer edge. When the crack propagates to 0.3-0.5 mm, it reaches the rail surface, causing the rail material to peel or fall off.
Article
Engineering, Mechanical
Hadi Torkamani, Aleks Vrcek, Roland Larsson, Marta-Lena Antti
Summary: Rolling-sliding contact fatigue experiments were conducted on bearing steels with different heat treatment procedures to study their wear and surface-initiated damage. It was found that the initial stress distribution and wear behavior of the specimens varied with heat treatment and hardness difference. The results were mainly explained based on residual stresses, microstructural features, and wear behavior of the specimens.
Article
Engineering, Mechanical
Xiaotong Zhu, Jinzhi Pan, Deyi Liu, Xiujuan Zhao, Ruiming Ren
Summary: This research studied the impacts of the surface ultrasonic rolling process (SURP) on G20Cr2Ni4A carburized bearing steel, including surface morphology, microstructure, residual stress distribution, and rolling contact fatigue (RCF) properties. The results showed that SURP not only reduced surface roughness, but also enhanced residual compressive stress and hardness, improving the resistance to surface cracks and enhancing RCF life. Microscopic analysis revealed that fatigue cracks easily formed between the ground layer and the matrix, causing spalling and shortening fatigue life. SURP prevented the formation of fatigue cracks and improved contact fatigue life.
