Influence of advanced load simulation models on fatigue design of jackets for offshore wind turbines.

Constant developments in the field of offshore wind energy have increased the range of water depths at which wind farms are planned to be installed. Therefore, in addition to monopile support structures suitable in shallow waters (up to 30 m), different types of support structures, able to withstand severe sea conditions at the greater water depths, have been developed. For water depths above 30 m, the jacket is one of the preferred support types. Jacket represents a lightweight support structure, which, in combination with complex nature of environmental loads, is prone to highly dynamic behavior. As a consequence, high stresses with great variability in time can be observed in all structural members. The highest concentration of stresses occurs in joints due to their nature (structural discontinuities) and due to the existence of notches along the welds present in the joints. This makes them the weakest elements of the jacket in terms of fatigue. In the numerical modeling of jackets for offshore wind turbines, a reduction of local stresses at the chord-brace joints, and consequently an optimization of the model, can be achieved by implementing joint flexibility in the chord-brace joints. Therefore, in this work, the influence of joint flexibility on the fatigue damage in chord-brace joints of a numerical jacket model, subjected to advanced load simulations, is studied.

A comparative analysis of seismic design strategies for R.C. frame structures

Negli ultimi anni sono state sviluppate varie soluzioni tecniche per la progettazione sismica di strutture. Questa ricerca sviluppa un metodo di confronto basato sull'analisi di costi di costruzione e danni causati dal sisma. Il metodo viene applicato al caso di studio della scuola di Bisignano (CO, Italia). L'edificio è stato progettato conformemente alle NTC 2008 con approccio tradizionale e combinando il contributo di dissipatori viscosi e dissipazione isteretica. Le strutture vengono poi analizzate sotto diverse condizioni sismiche al fine di calcolare i costi di riparazione attesi e comprendere quale soluzione tecnica risulti più economicamente vantaggiosa a parità di azione sismica di progetto.

Environmental impact assessment of the School of Engineering and Architecture (Lazzaretto) - A pathway towards LEED certification

The current work has for object the improvement and the maintenance of the School of Engineering and Architecture in Via Terracini 28 (Bologna), with the prospective to maximize the operative efficiency reducing to the minimum the environmental impact and the costs. In order to realize this work the LEED certification has been used. LEED (Leadership in Energy and Environmental Design) is a certification system of the buildings. It was born in United States by the U.S. Green Building Council (USGBC)