Federico Cluni

Mathematical models fornonlocal elastic composite materials

Abstract In this paper we derive and solve nonlocal elasticity a model describing the elastic behavior of composite materials, involving the fractional Laplacian operator. In dimension one we consider in ((

Performance evaluation of monumental bridges: testing and monitoring ‘Ponte delle Torri’ in Spoleto

\mathcal{D}

Longitudinal waves in a nonlocal rod by fractional Laplacian

)) the case of a nonlocal elastic rod restrained at the ends, and we completely solve the problem showing the existence of a unique weak solution and providing natural sufficient conditions under which this solution is actually a classical solution of the problem. For the model ((

Homogenization of non-periodic masonry structures

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A parametric investigation of wind-induced cable fatigue

)) we also perform numerical simulations and a parametric analysis, in order to highlight the response of the rod, in terms of displacements and strains, according to different values of the mechanical characteristics of the material. The main novelty of this approach is the extension of the central difference method by the numerical estimate of the fractional Laplacian operator through a finite-difference quadrature technique. For higher dimensions N ≥ 2 {N\geq 2} we study more general problems for which the existence of weak solutions is proved via variational methods. The obtained results provide an original contribute in the knowledge of composite materials with properties of nonlocal elasticity.

Enhancement of thermographic images as tool for structural analysis in earthquake engineering

This paper reports the main results of the experimental approach used for identifying the structural parameters and monitoring the dynamic response to the environmental loading of Ponte delle Torri (Towers Bridge) in Spoleto, Italy. In particular, the masonry wall drillings and laboratory tests on the cores obtained are described, together with the endoscopic survey and the flat-jack tests aimed to characterize the masonry mechanical characteristics. Then, the main focus is on the monitoring system, which is constituted of displacement transducers placed on the major cracks in the piers, seismic accelerometers placed on the bridge elevation next to the bridge deck, and a system of two ultrasonic anemometers which are used to record the wind speed fluctuations simultaneously with the bridge lateral accelerations. The results obtained give useful information to assess the actual state of the bridge and can be used for future decision making in planning maintenance strategies and restoration/consolidation campaigns.

Applications of sampling Kantorovich operators to thermographic images for seismic engineering.

ABSTRACT The article deals with the longitudinal waves in a nonlocal elastic rod. Regarding the nonlocal elasticity the Eringeen model has been assumed; the novelty is that this model is described in terms of the fractional Laplace operator. The standing waves are obtained by numerical solutions of the fractional differential equation in one-dimensional continuum. The obtained results are in accordance with the ones reported in the literature and highlight the dispersion phenomenon. The effects of the nonlocal contribution and of the fractional Laplacian order are also analyzed.