English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Electrical contact resistance or capacitance as measured between a lubricatedcontact has been used in tribometers, partially reflecting the lubricationcondition. In contrast, the electrical impedance provides rich information ofmagnitude and phase, which can be interpreted using equivalent circuit models,enabling more comprehensive measurements, including the variation of lubricantfilm thickness and the asperity (metal to metal) contact area. An accuratecircuit model of the lubricated contact is critical as needed for theelectrical impedance analysis. However, existing circuit models are handderived and suited to interfaces with simple geometry, such as parallel plates,concentric and eccentric cylinders. Circuit model identification of lubricatedcontacts with complex geometry is challenging. This work takes the ball-on-disclubricated contact in a Mini Traction Machine (MTM) as an example, where screwson the ball, grooves on the disc, and contact close to the disc edge make theoverall interface geometry complicated. The electrical impedance spectroscopy(EIS) is used to capture its frequency response, with a group of load, speed,and temperature varied and tested separately. The results enable anidentification of equivalent circuit models by fitting parallelresistor-capacitor models, the dependence on the oil film thickness is furthercalibrated using a high-accuracy optical interferometry, which is operatedunder the same lubrication condition as in the MTM. Overall, the proposedmethod is applicable to general lubricated interfaces for the identification ofequivalent circuit models, which in turn facilitates in-situ tribo-contactswith electric impedance measurement of oil film thickness. It does not needtransparent materials as optical techniques do, or structural modifications forpiezoelectric sensor mounting as ultrasound techniques do.

Using electrical impedance spectroscopy to identify equivalent circuit  models of lubricated contacts with complex geometry: in-situ application to  mini traction machine