Numerical study of a Transmission Problem in Elasticity with kind damping
Kais Ammari, Vilmos Komornik, Mauricio Sepúlveda, Octavio Vera
TL;DR
This work analyzes a one-dimensional elasticity transmission problem with fractional (Caputo-like) damping, identifying the asymptotic behavior of the associated semigroup. By introducing an augmented diffusion-based model and employing semigroup theory, it proves strong stability and, depending on the damping parameter $\eta$, either polynomial decay or, when applicable, exponential-type behavior for the energy; the decay rates are shown to be optimal. A detailed numerical study using a finite-volume spatial discretization and a $\beta$-Newmark time-stepping scheme with an Crank–Nicolson treatment of the fractional term corroborates the theoretical rates, including a demonstrative wavefront reflection/refraction example and energy decay curves that align with the predicted $t^{-1}$ (for $\eta=0$) and $t^{-4}$ (for $\eta>0$, with $\alpha=0.5$) behaviors. The combination of analytical semigroup results and robust numerical validation provides a rigorous understanding of how fractional damping affects energy dissipation in transmission problems and offers a practical framework for simulating such systems. The findings have potential implications for designing damping mechanisms in composite elastic media where localized and fractional damping effects are relevant.
Abstract
We investigate a transmission problem featuring a specific type of damping. Our primary focus is on analyzing the asymptotic behavior of the associated semigroup, $({\mathcal S}_{\mathcal A}(t))_{t\geq 0}$. We demonstrate that this semigroup exhibits a polynomial rate of decay towards zero when the initial data is taken over the domain ${\mathcal D}({\mathcal A})$. Furthermore, we establish that this decay rate is optimal. To support our theoretical findings, we present a comprehensive numerical study that validates and illustrates the sharpness of the obtained decay rates.
