Ricerc@Sapienza

This paper evaluates, with the aid of dynamic numerical analyses, the seismic performance of a long-span suspension bridge that was provided with a dissipative foundation system, consisting of a gravel layer interposed between the foundation caisson and a group of foundation piles. This system was conceived to permit a controlled development of relative horizontal displacements between the caisson and the piles during strong motion, providing an intrinsic limitation to the maximum seismic forces transmitted to the tower structure.

The accuracy and efficiency of a numerical strategy for sequential nonlinear cyclic analyses of carbon nanotube nanocomposites are investigated. The computational approach resorts to a nonlinear 3D finite element implementation that seeks to solve the cyclic hysteretic response of the nanocomposite. A variant of the Newton-Raphson method within a time integration scheme is proposed whereby the elastic tangent matrix is chosen as iteration matrix without paying the price of its iterative update.