Effective thermal conduction of a Signorini-type problem in composites with rough interface
Sara Monsurrò, Carmen Perugia, Federica Raimondi
TL;DR
This paper analyzes heat conduction in a two-component cylinder separated by a rapidly oscillating rough interface under Signorini-type transmission that couples the jump in temperature to the interface flux via a parameter $\gamma$. It develops a homogenization framework for $\varepsilon$-periodic coefficients and an oscillating interface with amplitude $\varepsilon^k$, casting the problem as a variational inequality on a split domain and deriving uniform a priori bounds. The main result identifies three regimes for $\varepsilon\to 0$ depending on $(k,\gamma)$: (A) a Signorini-type homogenized problem on a flat interface with an effective term $h_{\gamma,k}$, (B) a semi-conductive interface of negligible thickness, and (C) a homogenized Dirichlet problem on the whole cylinder; the homogenized tensor $A^0$ is obtained from a standard cell problem. The analysis hinges on carefully chosen test functions to pass to the limit and on handling products of weakly convergent sequences via lower semicontinuity, providing a rigorous link between micro-roughness and macroscopic thermal properties.
Abstract
We analyse the effect of a Signorini-type interface condition on the asymptotic behaviour, as ε tends to zero, of a problem posed in an open bounded cylinder of {R^N}, {N\geq 2}, divided in two connected components by an imperfect rough surface. The Signorini-type condition is expressed by means of two complementary equalities involving the jump of the solution on the interface and its conormal derivative via a parameter γ. Different limit problems are obtained according to the values of γ and the amplitude of the interface oscillations.
