Comparison of 2 methodologies developed for the determination of residual stresses through X-ray diffraction: application to a textured hcp titanium alloy
For polycrystalline materials, the experimental determination of residual stresses neglects the so-called 2nd order fluctuations arising from e.g. plastic or thermal incompatibilities from grain to grain. This constitutes a serious limitation of the classical measurements methods, since these 2nd residual stresses are known to have a major influence on the mechanical behavior of metallic alloys, especially if these are strongly textured. In the present paper, a new methodology for the treatment of the measured data is described and compared to classical ones. In order to do so, the simulation of a tensile test is performed using a self-consistent elasto-plastic model, in order to constitute a virtual experimental data set. The 1st and 2nd order stresses are extracted from the simulation for various macroscopic stress levels. Two approaches (the classical sin2ψ method and a method based on the simultaneous analysis of several X-ray diffraction peaks) are then used to quantify the 1st order stresses from these “experimental” data. It is clearly shown that the method based on multi-peak analysis allows to minimize the error made by neglecting the so-called 2nd order stresses and leads to a better quantitative estimation of the 1st order stresses.
KeywordsResidual stresses Hcp structure Titanium alloys Self-consistent model X-ray diffraction (XRD)
Fruitful discussions about residual stresses with D. Aliaga and N. Guillemot from Airbus Helicopters are acknowledged.
Compliance with ethical standards
The authors would like to thank the Conseil Général de Seine St Denis (CG93) for the attribution of a PhD fellowship to S. Dufrenoy.
Conflict of interest
The authors declare that they have no conflict of interest.
- 2.Bretheau T, Castelnau O (2006), Les contraintes résiduelles : d'où viennent-elles ? Comment les caractériser ?, in Rayons X et Matière. Lavoisier. p. 123–153Google Scholar
- 7.Afnor, J. Non-destructive Testing — Test Method for Residual Stress analysis by X-ray Diffraction. AFNORGoogle Scholar
- 12.Hutchinson J (1970) Elastic-plastic behaviour of polycrystalline metals and composites. Proceedings of the Royal Society of London Series a-Mathematical and Physical Sciences, 319(1537): 247-&Google Scholar
- 26.Dufrenoy, S., B. Bacroix, C. Th., I. Lemaire, N. Guillemot, and G. Thomas (2015) Influence of surface integrity on fatigue limit: Ti-10V-2Fe-3Al titanium application. In 13th World Conference on Titanium. San Diego, USA: TMSGoogle Scholar
- 27.Belkhabbaz, A., R. Brenner, N. Rupin, B. Bacroix, and J. Fonseca (2011) Prediction of the overall behavior of a 3D microstructure of austenitic steel by using FFT numerical scheme, in 11th International Conference on the Mechanical Behavior of Materials. M. Guagliano and L. Vergani, (Eds), 1883–1888Google Scholar
- 28.Dufrenoy S, Chauveau T, Brenner R, Fontugne C, Bacroix B (2014) Modeling methodology for stress determination by XRD in polycrystalline materials. Residual Stresses Ix 996:106–111Google Scholar