We are pleased to announce the seminar of

Pr. Michele SERPILLI, Associate professor of Università Politecnica delle Marche, on the "Multiphysic imperfect interfaces models : asymptotic analysis and numerical validation". 

On 09/02/2022 at 13h15 via Teams, and face-to-face in Amphi 3 at ISAE-Supméca.

Abstract:  

In the last decades, the interest in bonded structures, obtained by assembling different parts made of possibly different materials to compose a unique structure, is strongly increased. The advantage of such composites is that their mechanical performances and properties are designed to be superior to those of the constituent materials acting independently.

In the present study, the attention is focused on a specific type of composite, constituted by two media, called the adherents, bonded together with a thin interphase layer, called the adhesive. The composite constituents are made of different linear multiphysic materials with highly contrasted constitutive properties. The study considers a generic multiphysic coupling in a very general framework and can be adapted to well-known multiphysic behaviors, such as piezoelectricity, thermo-elasticity, as well as to multifield microstructural theories, such as micropolar elasticity.

The analysis has been carried out by means of asymptotic expansions method. By defining a small parameter ε, associated with the thickness and constitutive properties of the middle layer, an asymptotic analysis is performed. The middle layer thickness depends linearly on ε, while the multiphysic stiffness ratios between the adherents and the adhesive depend on ε^p. Three different limit models and their associated limit problems are characterized : the soft interface model, in which the constitutive coefficients depend linearly on ε ; the hard interface model, in which the constitutive properties are independent of ε ; the rigid interface model, in which they depend on 1/ ε. The asymptotic expansion method is reviewed by taking into account the effect of higher order terms and by defining a general multiphysic interface law which comprises the above aforementioned models.

Finally, some numerical examples are given in order to show the efficiency of the proposed methodology in the case of piezoelectric and thermo-mechanical couplings. The numerical investigations are performed in the framework of the finite element method. In particular, finite elements are introduced to solve the fully 3D initial problem, considering a three-phase composite, and the limit 3D-2D problem with two layers with imperfect interface transmission conditions.

Biographie:

Michele Serpilli obtained his Ph.D. Degree in Mécanique et Génie Civil in 2008 at the Université de Montpellier II, France. From 2008 to 2019, he worked as Research Assistant at the Department of Civil and Building Enginnering, and Architecture, Università Politecnica delle Marche, Ancona. From 2019 to present, he is Associate Professor in Structural Mechianics in the same Department. His main research interests are : 1) Asymptotic analysis ; 2) Asymptotic modeling of thin structure and composites ; 3) Interface and contact laws ; 4) Multifield and multiphysic couplings ; 5) Experimental methods for sustainable costructions.