Eigenstrain modelling of residual stresses generated by laser shock peening
Eigenstrain modelling of residual stresses generated by laser shock peening
This paper presents an eigenstrain (misfit strain) model of the residual stresses generated by laser shock peening (LSP). The shock wave is first modelled as a dynamic pressure load in an explicit finite element(FE) model and the stabilised plastic strain distribution is extracted. This strain distribution is then incorporated as an eigenstrain distribution in a static FE model and the residual stresses generated by the original shock wave are obtained as the elastic response to the eigenstrain. In order to focus on the basic mechanics, an elastic-perfectly plastic material model is assumed. Similarly, a simplified pressure/time variation (a triangular ramp with the peak pressure occurring at the half the total pulse duration) is assumed in order to characterise the pressure pulse. The peak pressure and the duration of the pressure pulse are determined in a way that they are consistent with experimental results. The analysis is extended to study the case of multiple pulses and the results show that the process generates compression in a surface layer of about 1.5–2mmdeep. Furthermore, the results demonstrate that the magnitudes of subsurface tensile stresses are of the order of one fifth of the material’s yield strength for typical peening conditions.
laser shock peening, eigenstrain, residual stress
1091-1101
Achintha, M.
8163c322-de6d-4791-bc31-ba054cc0e07d
Nowell, D.
587adb58-8b15-4efc-bc16-4071a35747f6
1 June 2011
Achintha, M.
8163c322-de6d-4791-bc31-ba054cc0e07d
Nowell, D.
587adb58-8b15-4efc-bc16-4071a35747f6
Achintha, M. and Nowell, D.
(2011)
Eigenstrain modelling of residual stresses generated by laser shock peening.
Journal of Materials Processing Technology, 211 (6), .
(doi:10.1016/j.jmatprotec.2011.01.011).
Abstract
This paper presents an eigenstrain (misfit strain) model of the residual stresses generated by laser shock peening (LSP). The shock wave is first modelled as a dynamic pressure load in an explicit finite element(FE) model and the stabilised plastic strain distribution is extracted. This strain distribution is then incorporated as an eigenstrain distribution in a static FE model and the residual stresses generated by the original shock wave are obtained as the elastic response to the eigenstrain. In order to focus on the basic mechanics, an elastic-perfectly plastic material model is assumed. Similarly, a simplified pressure/time variation (a triangular ramp with the peak pressure occurring at the half the total pulse duration) is assumed in order to characterise the pressure pulse. The peak pressure and the duration of the pressure pulse are determined in a way that they are consistent with experimental results. The analysis is extended to study the case of multiple pulses and the results show that the process generates compression in a surface layer of about 1.5–2mmdeep. Furthermore, the results demonstrate that the magnitudes of subsurface tensile stresses are of the order of one fifth of the material’s yield strength for typical peening conditions.
Text
oxon_1.pdf
- Version of Record
Restricted to Repository staff only
Request a copy
More information
e-pub ahead of print date: 28 January 2011
Published date: 1 June 2011
Keywords:
laser shock peening, eigenstrain, residual stress
Organisations:
Infrastructure Group
Identifiers
Local EPrints ID: 209483
URI: http://eprints.soton.ac.uk/id/eprint/209483
ISSN: 0924-0136
PURE UUID: 0b05938b-353c-44bc-901f-549b5385a41e
Catalogue record
Date deposited: 30 Jan 2012 10:26
Last modified: 14 Mar 2024 04:46
Export record
Altmetrics
Contributors
Author:
M. Achintha
Author:
D. Nowell
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics