Space-resolved diffusing wave spectroscopy measurements of the macroscopic deformation and the microscopic dynamics in tensile strain tests Auteur(s): Nagazi M. Y., Brambilla G., Meunier Gérard, Marguerès Philippe, Périé Jean-Noël, Cipelletti L. (Article) Publié: Optics And Lasers In Engineering, vol. 88 p.5 - 12 (2016) Texte intégral en Openaccess : Ref HAL: hal-01292690_v1 Ref Arxiv: 1603.06384 DOI: 10.1016/j.optlaseng.2016.07.006 WoS: 000385319500002 Ref. & Cit.: NASA ADS Exporter : BibTex | endNote 16 Citations Résumé: We couple a laser-based, space-resolved dynamic light scattering apparatus to a universal testing machine for mechanical extensional tests. We perform simultaneous optical and mechanical measurements on polyether ether ketone, a semi-crystalline polymer widely used in the industry. Due to the high turbidity of the sample, light is multiply scattered by the sample and the diffusing wave spectroscopy (DWS) formalism is used to interpret the data. Space-resolved DWS yields spatial maps of the sample strain and of the microscopic dynamics. An excellent agreement is found between the strain maps thus obtained and those measured by a conventional stereo-correlation bench. The microscopic dynamics reveals both affine motion and plastic rearrangements. Thanks to the extreme sensitivity of DWS to displacements as small as 1 nm, plastic activity and its spatial localization can be detected at an early stage of the sample deformation, making the technique presented here a valuable complement to existing material characterization methods. |