Eigenstrain modelling of residual stress generated by arrays of Laser Shock Peeing shots and determination of the complete stress field using limited strain measurements


Achintha, M., Nowell, D., Shapiro, K. and Withers, P.J. (2012) Eigenstrain modelling of residual stress generated by arrays of Laser Shock Peeing shots and determination of the complete stress field using limited strain measurements. Surface and Coatings Technology (doi:10.1016/j.surfcoat.2012.11.027).

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Description/Abstract

This paper presents a hybrid explicit finite element (FE) /eigenstrain model for predicting the residual stress generated by arrays of adjacent/overlapping laser shock peening (LSP) shots where the use of a completely explicit FE analysis may be impractical. It shows that for a given material, the underlying eigenstrain distribution (in contrast to the resulting stress field) representing a laser shock peen is primarily dependent on the parameters of the laser pulse and the number of overlays rather than the precise component geometry. Consequently the residual stress introduced by complex laser peening treatments can be built up by using static FE models and superposition of individual eigenstrain distributions without recourse to further computationally demanding explicit FE analyses. It is found that beneath a small patch of LSP array the magnitude of the compressive residual stress is higher than for a wider array of LSP shots and that with increasing numbers of layers the compressive stress increases as does the depth of the compressive zone. The model predictions for the eigenstrain distributions are compared well with experimental measurements of plastic strain (full-width-at-half-maximum) obtained by neutron diffraction. The eigenstrain method is also extended to construct the full residual stress field using measured residual elastic strains at a finite number of measurement locations in a component.

Item Type: Article
ISSNs: 0257-8972 (print)
0257-8972 (electronic)
Related URLs:
Subjects: T Technology > T Technology (General)
Divisions: Faculty of Engineering and the Environment > Civil, Maritime and Environmental Engineering and Science > Infrastructure Research Group
ePrint ID: 345424
Date Deposited: 20 Nov 2012 15:53
Last Modified: 27 Mar 2014 20:27
Projects:
Structural Integrity of Components with Deep Compressive Residual Stresses
Funded by: EPSRC (EP/F026226/1)
November 2008 to December 2011
Structural Integrity of Components with Deep Compressive Residual Stresses
Funded by: EPSRC (EP/F026730/1)
September 2008 to February 2012
URI: http://eprints.soton.ac.uk/id/eprint/345424

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