Michele Serpilli

Asymptotic Expansions and Domain Decomposition

We apply the domain decomposition method to linear elasticity problems for multi-materials where the heterogeneities are concentrated in a thin internal layer. In the first case the heterogeneities are small, identical and periodically distributed on an internal surface and in the second one all the thin, curved internal layer is made of an elastic material much more strong than the surrounding one. In the first case the domain decomposition is used to efficiently solve the non-standard transmission problems obtained by the asymptotic expansion method. In the second case a non-standard membrane transmission problem originates from a surface shell like energy.

An asymptotic plate model for magneto-electro-thermo-elastic sensors and actuators

We present an asymptotic two-dimensional plate model for linear magneto-electro-thermo-elastic sensors and actuators, under the hypotheses of anisotropy and homogeneity. Four different boundary conditions pertaining to electromagnetic quantities are considered, leading to four different models: the sensor–actuator model, the actuator–sensor model, the actuator model and the sensor model. We validate the obtained two-dimensional models by proving weak convergence results. Each of the four plate problems turns out to be decoupled into a flexural problem, involving the transversal displacement of the plate, and a certain partially or totally coupled membrane problem.

On modeling interfaces in linear micropolar composites

This paper describes the mechanical behavior of two linear micropolar solids, bonded together by a thin plate-like layer, constituted of a linear micropolar material, determined by means of an asymptotic analysis. After defining a small parameter ε , which will tend to zero, associated with the thickness and the constitutive coefficients of the intermediate layer, we characterize two different limit models and their associated limit problems, the so-called weak and strong micropolar interface models, respectively. Moreover, we identify the nonclassical transmission conditions at the interface between the two three-dimensional bodies in terms of the increases in the stresses, coupling stresses, displacements, and microrotations. Finally, we prove that the solution of the original problems strongly converges toward the solution of the limit problems, as ε tends to zero.