A study of rolling contact fatigue in electric vehicles (EVs)

Supervisory Team:   Prof. Ling Wang and Prof. Andy Cruden

Project description

Applications are invited for a fully-funded PhD studentship studying the influence of electoral current on rolling element bearings in electricial vehicles (EVs). This research is relevant to all engineering applications that are subject to electrification, such as electric cars, trains and aeroplanes. Successfully completing this project will equipped the doctoral graduate with knowledge and skills demanded by future industry especially those related to e-mobility.

With the rapid increase of manufacturing and usage of electric vehicles (EVs) as a direct response to the global challenge of climate change and meet the zero emissions target, the sustainability and longevity of EVs is becoming more important than ever. As the critical component in EVs, the impact of its bearing failures caused by electrification is paramount and will hinder the growth of this technology in the near future.

Rolling element bearings, invented since 40 BC, have become one of the most critical and reliable tribological components in rotating machines such as engines and motors. They are found to be subject to much harsher operating conditions in EVs than those in conventional internal combustion engines (ICEs) due to the much higher rotating speeds and unexpected electrification. These put bearings at much higher risk of failure in EV motors. Previous studies have shown a relatively low stray current in motor bearings can cause severe electrical pitting damages on bearing surfaces, leading to reduced rolling contact fatigue (RCF) lives.

This PhD will investigate the influence of electrification on bearing RCF life, providing a comprehensive understanding of their failure mechanisms as well as solutions to future sustainable EVs. The study involves tribological testing of bearing steels on a twin-roller tribo-meter, where the contact is subject to an electrical current of a range of amplitudes and frequencies. Post test metallographic analysis will provide insight to the failure mechanisms. Novel sensors such as electrostatic sensing techniques will be used to monitor charging-discharging event at the contact to ilucidate the causes of bearing failures under electrification. Materials and lubrication solutions may be investigated by testing other materials and lubricants with different electrical properties that support the development of solutions to RCF failures in EVs. 

The successful candidate will be part of two research groups (nCATS and Energy Technologies) within the Mechanical Engineering Department at University of Southampton, who are global leaders in tribology and energy techniques including electrical engineering research. Trainings will be provided to the student at the beginning of the project to help the student start the investigation and technical supports are available throughout the entire PhD duration to ensure the success of the research project.

Entry Requirements

A very good undergraduate degree (at least a UK 2:1 honours degree, or its international equivalent).

Closing date: 31 August 2022.

Funding: Tuition Fees and a stipend (UK Only) of £16,062 p.a for up to 3.5 years.

How To Apply

Apply online: https://www.southampton.ac.uk/courses/how-to-apply/postgraduate-applications.page. Select programme type (Research), 2022/23, Faculty of Physical Sciences and Engineering, next page select “PhD Engineering & Environment (Full time)”. In Section 2 of the application form you should insert the name of the supervisor Ling Wang

Applications should include:

Curriculum Vitae

Two reference letters

Degree Transcripts to date

For further information please contact: feps-pgr-apply@soton.ac.uk