1,721,174 research outputs found
Progettazione di ponti dotati di sistemi di isolamento sismico a comportamento fortemente non lineare
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Valutazione delle caratteristiche degli elementi strutturali degli edifici esistenti e della sicurezza sismica mediante metodi approssimati
No full textComportamento dinamico di un telaio in c.a. dotato di dispositivi basati su leghe a memoria di forma
No full textUtilizzo delle Leghe a Memoria di Forma e di sistemi innovativi di rafforzamento delle murature nell’adeguamento sismico di strutture monumentali
No full textSMA-based Tension Control Block for metallic tendons
No full textMetallic tendons are frequently used in arches and vaults to absorb the lateral thrusting forces due to gravity loads or inertial forces caused by an earthquake. Traditional tendons, however, have some limitations (e.g. sensitivity to temperature variations, buckling under compression, etc.). Shape Memory Alloys (SMAs) can be used to enhance the performances of metallic tendons both in service and seismic conditions. This is achieved with the tensioning control block (TCB) system. The basic components of
TCB are pre-strained superelastic SMA wires, in series with the metallic tendon. The number and diameter of the SMA wires is selected based on the force levels to reach. The length is optimised with respect to the thermal behavior of the system. A number of theoretical and experimental studies have been conducted to fully understand the thermal and mechanical behavior of TCB. In the paper, the main outcomes of these studies are described
Direct Displacement-Based Design of Seismically Isolated Bridges
No full textA Displacement-Based Design (DBD) procedure for bridges equipped with different seismic Isolation Systems (IS’s) is proposed. It has been derived from the Direct DBD method recently developed by Priestley and co-workers. The key aspect of the proposed procedure is the definition of a uniform target displacement of the deck, which is assigned by the designer to accomplish a given performance level, expressed through limit values of the maximum IS displacement and of the pier drift, respectively. The proposed design procedure has been developed for four different idealized force-displacement cyclic behaviours
of IS’s, which can be used to describe the response of a wide variety of IS’s, including: (i) Lead-Rubber Bearings (LRB), (ii) High-Damping Rubber Bearings (HDRB), (iii) Friction Pendulum Bearings (FPB), (iv) Combinations of either Low-Damping Rubber Bearings (LDRB) or FPB and Viscous Dampers (VD), (v) Combinations of lubricated Flat Sliding Bearings (FSB) and LDRB, (vi) Combinations of FSB and Steel Yielding Devices (SYD), (vii) Combinations of FSB, Shape Memory Alloy (SMA)-based Re-centring Devices and VD. In the paper, the background and implementation of the design procedure is presented first, then some validation studies through nonlinear time-history analyses on different configurations of continuous deck and multi-span simply supported deck bridges are illustrated
Confronto tra diverse procedure per la valutazione della vulnerabilità di edifici scolastici in c.a.
No full textAtto del Dipartimento di Strutture, Geotecnica, Geologia applicata all'ingegneria dell'Università della Basilicat
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