Anisotropic wave propagation within strain gradient framework
The objective of this talk is to present recent results in the domain of anisotropic and dispersive wave propagation within the framework of linear strain-gradient elasticity. This analysis reveals significant features of this extended theory of continuum elasticity. Indeed, contrarily to classical elasticity, wave propagation in hexagonal (chiral or achiral) lattices becomes anisotropic as the frequency increases. These points are first theoretically derived, and then numerically experienced on hexagonal chiral and achiral lattices. The use of a continuum model for the description of the high frequency behaviour of microstructured materials can be of great interest in engineering applications, allowing problems with complex geometries to be more easily treated.
When using these continuum models, one of the main problems is the identification of the homogenised parameters. In this talk I will illustrate a mixed numerical static-dynamic approach, based on static measures with rich boundary conditions and dynamic measures of phase velocity based on Bloch analysis. These procedure can also be applied experimentally.
* G. Rosi and N. Auffray, Anisotropic and dispersive wave propagation within strain-gradient framework, Wave Motion , vol. 63, pp. 120-134, 2016.
* N. Auffray, J. Dirrenberger, and G. Rosi, A complete description of bi-dimensional anisotropic strain-gradient elasticity Int. J. Solids.Struct., vol. 69, pp. 195-206, 2015.
Nicolas Auffray (20/03/1981), is an associate professor at Laboratoire MSME, Université Paris-Est Marne-la-Vallée.He received PhD degree from ONERA (French Aerospace Lab) on the modelling of architectured materials under the supervision of Y. Brechet (Grenoble University and French academy of science). Dr.Auffray’s research interests include anisotropic elasticity, homogenization, elastodynamics, generalized continuum theories, mechanics of architectured materials and group theory in continuum mechanics. He is author of 23 articles in peer-reviewed journals, 2 book chapters, 15 communications in national and international journals. He won Jean Mandel Prize, from l’Ecole des Mines de Paris and l'EcolePolytechnique.