Probing non-affine expansion with light scattering

Abstract

In disordered materials under mechanical stress, the produced deformation can deviate from the affine one already in the elastic regime. The nonaffine contribution was observed and characterized in numerical simulations for various systems. However, low amplitude of nonaffinity and its local character makes the experimental study challenging. We present a novel method on the based on a phase compensation of the wave scattered from a dilated amorphous material using fine wavelength tuning of the optical probe beam. Using a glass frit as a sample, we provide complete reversibility of the material deformation which enables to confirm the occurrence of nonaffinity in the elastic regime. We develop a model for the coupled effect of the thermal expansion/contraction of the material and the dilatation of the incident wavelength which allows us to estimate the magnitude of the nonaffine displacement and the spatial extent of its correlation domain.

References in corpus (13)

• Jamming at Zero Temperature and Zero Applied Stress: the Epitome of Disorder
• Jamming of Soft Particles: Geometry, Mechanics, Scaling and Isostaticity
• Approximate analytical description of the nonaffine response of amorphous solids
• Continuum limit of amorphous elastic bodies: A finite-size study of low frequency harmonic vibrations
• A coordination-based approach to elasticity of floppy and stiff random networks
• Deformation and flow of a two-dimensional foam under continuous shear
• Nonaffine Correlations in Random Elastic Media
• Critical and non-critical jamming of frictional grains
• Non-affine displacements in flexible polymer networks
• Microscopic dynamics and failure precursors of a gel under mechanical load
• Determination of the diffusion constant using phase-sensitive measurements
• Spatially-resolved measurements of micro-deformations in granular materials using DWS
• A novel setup coupling space-resolved dynamic light scattering and rheometetry unveils the heterogeneous flow field and non-affine dynamics in startup shear of a gel