Chandrasekar_Prasanth.pdf (13.59 MB)
The influence of stress level on the ratcheting magnitude and progress rate in steel alloys under uniaxial loading conditions
thesis
posted on 2021-05-22, 11:17 authored by Prasanth ChandrasekarEngineering materials in their service life undergo symmetric or asymmetric fatigue loading,
which leads to fatigue damage in the material. Ratcheting damage is due to the application of mean
stress under cyclic loading condition. From deformation behavior perspective, application of mean
stress under stress-controlled fatigue loading gives rise to accumulation of plastic strain in the
material. Ratcheting strain increases with an increase in applied mean stress and stress amplitude.
In addition, ratcheting behavior will increase in cyclic damage with the rise in strain accumulation
and it can be illustrated by a shift in the hysteresis loop towards large plastic strain amplitudes.
This study focuses on the ratcheting behavior of different steel materials under uniaxial cyclic
loading condition and suggests a suitable method to arrest ratcheting by loading the materials at
zero ratcheting strain rate condition with specified mean stress and stress amplitudes. The three
dimensional surface is created with stress amplitude, mean stress and ratcheting strain rate for
different steel materials. This represents a graphical surface zone to study the ratcheting strain rates
for various mean stress and stress amplitude combinations.
History
Language
engDegree
- Master of Engineering
Program
- Aerospace Engineering
Granting Institution
Ryerson UniversityLAC Thesis Type
- Thesis