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Rolling bearings often cause engineering accidents due to early fatigue failure. The study of early fatigue failure mechanism and fatigue life prediction does not consider the integrity of the bearing surface. The purpose of this paper is to find new rolling contact fatigue (RCF) life model of rolling bearing.

An elastic-plastic finite element (FE) fatigue damage accumulation model based on continuous damage mechanics is established. Surface roughness, surface residual stress and surface hardness of bearing rollers are considered. The fatigue damage and cumulative plastic strain during RCF process are obtained. Mechanism of early fatigue failure of the bearing is studied. RCF life of the bearing under different surface roughness, hardness and residual stress is predicted.

To obtain a more accurate calculation result of bearing fatigue life, the bearing surface integrity parameters should be considered and the elastic-plastic FE fatigue damage accumulation model should be used. There exist the optimal surface parameters corresponding to the maximum RCF life.

The elastic-plastic FE fatigue damage accumulation model can be used to obtain the optimized surface integrity parameters in the design stage of bearing and is helpful for promote the development of RCF theory of rolling bearing.

This paper aims to investigate the effects of inhomogeneities on the rolling contact fatigue (RCF) life in elastohydrodynamically lubricated (EHL) point contacts.

A numerical model for predicting the RCF life of inhomogeneous materials in EHL contacts was established by combining the EHL model and the inclusion model through the eigen-displacement and then connecting to the RCF life model through the subsurface stresses. Effects of the type, size, location and orientation of a single inhomogeneity and the distribution of multiple inhomogeneities on the RCF life were investigated.

The RCF life of a half-space containing manganese sulfide (MnS) inhomogeneity or the mixed inhomogeneity of aluminium oxide (Al₂O₃) and calcium oxide (CaO) was longer than that for the case of Al₂O₃ inhomogeneity. For a single ellipsoidal MnS inhomogeneity, increases of its semi-axis length and decreases of its horizontal distance between the inhomogeneity and the contact center shortened the RCF life. Furthermore, the relationship between the depth of a single MnS inhomogeneity and the RCF life was found. For the half-space containing multiple inhomogeneitites, the RCF life decreased remarkably compared with the homogeneous half-space and showed discreteness.

This paper implements the prediction of the RCF life of inhomogeneous materials under EHL condition.

This chapter describes two change efforts involving participatory action research within the pharmacy operations division of Kaiser Permanente. Focus is on a parallel learning mechanism that has been used to support communications and change during two large-scale information technology interventions. It begins with basic background information on participatory action research in organizations. Since the case setting is Kaiser Permanente, the chapter provides some information on the U.S. healthcare industry context and then shifts to Kaiser’s communication forum, a learning mechanism that has been in place for 35 years. Cognitive, structural, and procedural aspects of the learning mechanism are explored, and the chapter features interviews with some of the key forum players. Both in the forum’s infancy and in its current more institutionalized state, the pharmacy organization has been in crisis. Implications for the use of parallel learning structures on a long-term basis to support long-term participatory action research are explored along with contributions to theory on insider/outsider action research.

A simple economic analysis has revealed that in order for wind energy to be a viable alternative, wind-turbines (convertors of wind energy into electrical energy) must be able to operate for at least 20 years, with only regular maintenance. However, wind-turbines built nowadays do not generally possess this level of reliability and durability. Specifically, due to the malfunction and failure of drive-trains/gear-boxes, many wind-turbines require major repairs after only three to five years in service. The paper aims to discuss these issues.

The subject of the present work is the so-called white etch cracking, one of the key processes responsible for the premature failure of gear-box roller-bearings. To address this problem, a multi-physics computational methodology is developed and used to analyze the problem of wind-turbine gear-box roller-bearing premature-failure. The main components of the proposed methodology include the analyses of: first, hydrogen dissolution and the accompanying grain-boundary embrittlement phenomena; second, hydrogen diffusion from the crack-wake into the adjacent unfractured material; third, the inter-granular fracture processes; and fourth, the kinematic and structural response of the bearing under service-loading conditions.

The results obtained clearly revealed the operation of the white-etch cracking phenomenon in wind-turbine gear-box roller-bearings and its dependence on the attendant loading and environmental conditions.

The present work attempts to make a contribution to the resolution of an important problem related to premature-failure and inferior reliability of wind-turbine gearboxes.

The aim of this study is to first investigate the surface integrity of cylindrical rollers under grinding process and then design a reasonable superfinishing process that improve the anti-fatigue performance of cylindrical rollers by optimization of the surface integrity.

First, the white and dark layers produced by the grinding process is analyzed by microscope. Then, the influence of oilstone pressure on the stock removal, surface precision and crowned profile are explored. Finally, an optimal superfinishing process and a novel turnaround device are designed to improve surface integrity.

The experimental results show that as the oilstone pressure increases, the stock removal first increases and then remains stable. This hints that the stock removal of a single-time superfinishing process has an upper limit. In the current conditions, the maximum stock removal is 6 µm. Double-time superfinishing process and the turnover device can effectively eliminate the white and dark layers and improve the symmetric of roller profile. In addition, the surface precision is also improved.

The surface integrity of bearing rollers is very important to the application of industry field. The findings and the methods in the study can be helpful to improve the surface integrity of the bearing rollers.

The purpose of this study is to reveal the tribological performance of the textured rolling bearing.

In the present study, the oil film pressure distribution and load capacity analysis method are established, which integrate the micro-texture model and Hydrodynamic lubrication (HL) methods. The tribological performances of the textured rolling bearing under the various working condition, texture dimension and texture type are investigated systematically.

The results show that the oil film load capacity increases with the increase in the texture size. As the texture depth increases, the oil film load capacity increases first and then decreases, and then the load capacity is the largest at the texture depth range of 3 to 5 µm. In addition, the oil film load capacity of the matching pairs, such as Si4N3-Si4N3, GCr15- Si4N3 and GCr15-GCr15 are compared; the results show that the cases of using ceramic material can improve oil film load capacity of textured rolling bearing.

The current manuscript can be useful for supporting the reliability and life research of textured rolling bearing.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0055

This study aims to investigate the effect of compound pit textures on the tribological properties of thrust cylindrical roller bearings (TCRBs) using several parameters, such as compound type, pit diameter, pit depth and pit area density.

The surface texture parameters of the shaft washer (WS) raceway include pit diameter (D; 100, 300 and 500 µm), pit depth (H; 10 and 20 µm) and pit area density (S; 10%, 13% and 18%). Pits were produced on the WS of the TCRBs using laser marking equipment. The friction and wear performances of compound pit-textured TCRBs under starved lubrication conditions are studied using a friction and wear test rig. The influence mechanisms of the compound pit texture on the friction and wear properties of TCRBs are discussed through real tests and discussions.

Compared with nontextured bearings, the average coefficient of friction (ACOFs) and wear loss of TCRBs with single/compound pit textures are reduced when rotating under starved lubrication. D has the greatest effect on the COFs curve. When D = 300 µm, H = 10 µm and S = 10%, the ACOF and wear loss are the lowest, that is, 0.0207 and 3.38 mg, respectively. Under the same lubrication conditions, compared with the nontextured bearing group, the COF and wear loss are reduced by 41.4 and 59.6%, respectively.

This study provides a useful reference for the raceways of textured TCRBs.

The purpose of this paper is to present the research carried out on the development of a conceptual framework termed as the reverse collaboration framework (RCF) to provide supply chain (SC) visibility and information sharing to practitioners in a reverse logistics (RL) operations.

The research methodology used in this research is a combination of concept mapping, and the extension of the work of other researchers (deductive approach) to develop a RCF that connects tools, techniques, systems and RL processes.

This research shows that by integrating tools, systems, tools and techniques with RL processes by means of the RCF will increase performance and productivity of a RL operations. This is demonstrated by applying the RCF to a consumer electronics business that proves that the time taken for the end to end RL operations is reduced by 20%.

The RCF has been demonstrated with the data from a consumer electronics organisation. Literature points out that there are many different mathematical models for RL across a number of industries. Thus, at this stage, it is not clear if the RCF developed in this research will work in other industries, such as the newspaper, plastic bottles and online retailers industry where product returns are high. This research work can be extended in developing an IT solution by future researchers that can be linked to the main ERP system of an organisation.

SC managers can use the RCF in the extended form of an IT solution to manage the RL operations of their organisations.

There is a lack of research in the space of reverse collaboration in the broader field of SC management. This paper has fulfilled that gap.

Starting from the state-of-the-art of Fintech development, this study aims to propose some research propositions comparing reward-crowdfunding (RCF) and equity-crowdfunding (ECF). In this sense, the present research provides a comprehensive analysis of fintech development and – to conceptualize the comparison between RCF and ECF – it focuses on campaigns’ characteristics, aims and post-campaigns scenarios.

All the research propositions related to the comparison between RCF and ECF are rooted in dedicated literature. The methodological approach adopted in the present paper can be referred to theorizing.

This study suggests that five key elements characterize the development of fintech: regulation, infrastructure, technologies, finance and innovations. The research provides nine propositions: four related to the campaigns’ characteristics; two related to the use of crowdfunding models by entrepreneurs; and three related to the performance of crowdfunded companies.

By offering nine research propositions, this study is expected to foster and support the investigation of fintech development from an entrepreneurial and managerial point of view.

To the best of authors’ knowledge, this study is among the first to explore the fintech development and to propose a comparative approach between RCF and ECF. This research contributes to the current debate on fintech development as well as on the comparison between crowdfunding models.

With an eye to prevent derailment of high-speed trains, vis-à-vis unwarranted loss of lives and property, this paper aims to develop a formalism of designing a suitable control system with embedded decision support system.

A model of rolling contact fatigue (RCF) crack propagation in railway tracks is designed, simulating the alarming stress intensity factor around the advancing fatigue cracks. COMSOL multi-physics software is employed to design the RCF crack monitoring system with acoustic emission (AE) count signals, describing the damage threshold of railway tracks.

Simulation experiment on stress intensity factor for cracks in real life rail sections has enabled to describe the maximum working stress; it has been noticed that the threshold value of stress intensity factor (∼ 41 MPa m1/2) for the onset of unstable crack propagation is reached at a fatigue crack length of 11.5 mm. It is further noticed that the observed AE count at a particular instant of time in a specific location of railway track is a true indication of the vulnerability of rail failures.

The proposed model, a completely new of its kind, bears a high socio-technological value as it entails the design of an intelligent control system to prevent train accidents.