Numerical and experimental investigation of shakedown in evolving non-Hertzian rolling contact

The non-conforming rolling contact under high loads results in considerable plastic deformation of the surface. This surface plastic flow is studied using a twin-disk tribometer, and the observed deformation as a function of the number of rolling cycles is classified into three distinct stages. Substantial geometric changes are observed in the initial stage and during this process, the contact type changed from Hertzian to non-Hertzian in the first few cycles, and then it changed from non-Hertzian back to near Hertzian by the end of this stage. A semi-analytical model is therefore employed to perform the contact analysis. Special elements are employed near the surface discontinuities within the contact area to resolve singularities. The contact area is observed to change from elliptic to a near-rectangular shape and the evolution of the contact parameters during this process is reported. Shakedown limits are obtained at different instants of the deformation process using Melan’s theorem. It is observed that the high stresses near the surface discontinuities greatly affect the shakedown limits. The actual stress state is observed to move on a shakedown map until it goes below the shakedown limit but above the elastic limit as predicted.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2021

Author dc:creator

• Jetti, Yaswanth Sai

Contributors dc:contributor

• Dunn, Alison C.

• shakedown
• non-Hertzian contact
• twin-disk testing
• pearlitic steel

Statement dc:rights

• Copyright 2021 Yaswanth Sai Jetti

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/110742

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/110742