Imperial College London
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ProfessorDavidNowell

Faculty of Engineering, Department of Mechanical Engineering

Chair in Machine Dynamics and Director of the VUTC
 
 
 
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Contact

 

+44 (0)20 7594 1458d.nowell Website

 
 
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Location

 

561City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Salvati:2016:10.1016/j.engfracmech.2016.04.034,
author = {Salvati, E and O, Connor S and Sui, T and Nowell, D and Korsunsky, AM},
doi = {10.1016/j.engfracmech.2016.04.034},
journal = {Engineering Fracture Mechanics},
pages = {210--223},
title = {A study of overload effect on fatigue crack propagation using EBSD, FIB-DIC and FEM methods},
url = {http://dx.doi.org/10.1016/j.engfracmech.2016.04.034},
volume = {167},
year = {2016}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Abrupt increase in the maximum load during fatigue cycling modifies the deformation conditions at the crack tip, causing plastic flow that may lead to crack closure, introducing residual stress and hardening. The net consequence of these effects is notable crack growth retardation. Despite decades of research in the field, controversy persists regarding the role of each specific mechanism and their interaction. Resolving these issues with the help of experimental observation is related to the difficulty of obtaining local residual stress information at appropriate resolution. The present study examines the effect of overload on fatigue crack grown in a Compact Tension (CT) specimen of aluminium alloy AA6082 (BS HE30). Fatigue crack was grown in the sample under cyclic tension (R = 0.1). After the application of a single overload cycle, fatigue loading was recommenced under previous cycling conditions. The crack morphology was investigated using Scanning Electron Microscopy (SEM). Electron Backscattered Diffraction (EBSD) was used to map grain orientation and crystal lattice distortion (pattern quality) in the vicinity of the crack. EBSD analysis of intra-granular misorientation allowed the qualitative analysis of the region around the crack tip location at the time of the overload application. Observations are discussed with a view to identify the roles of crack closure and residual stress effects. Residual stress was evaluated at salient locations around the crack retardation site using the FIB–DIC method which combines the use of Focused Ion Beam (FIB) and Digital Image Correlation (DIC) for residual stress measurement at the (sub)micron-scale. The residual stress field due to overload occurrence was also simulated using Finite Element Method (FEM), and the results compared with experimental observations.
AU  - Salvati,E
AU  - O,Connor S
AU  - Sui,T
AU  - Nowell,D
AU  - Korsunsky,AM
DO  - 10.1016/j.engfracmech.2016.04.034
EP  - 223
PY  - 2016///
SN  - 0013-7944
SP  - 210
TI  - A study of overload effect on fatigue crack propagation using EBSD, FIB-DIC and FEM methods
T2  - Engineering Fracture Mechanics
UR  - http://dx.doi.org/10.1016/j.engfracmech.2016.04.034
UR  - https://www.sciencedirect.com/science/article/pii/S0013794416301990?via%3Dihub
VL  - 167
ER  -
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