Search results for "Dissipator"
showing 5 items of 5 documents
Indagini teoriche e sperimentali su dissipatori ad attrito per edifici in acciaio in zona sismica
2017
The present paper presents the results of experimental analyses carried out to study the behaviour of slotted bolted connections (SBC) as friction steel dampers. The devices consist of bolted joints with slotted holes, which can be used in both steel and RC framed structures or, alternatively, into beam-column and column-foundation joints. The most suitable configurations to increase friction are investigated utilizing steel S355J0 plates and class 10.9HV high-strength bolts, under controlled pre-load and considering different types of surface treatment. Experimental tests are carried out making use of a universal testing machine, which allows mak-ing displacement-controlled tests. Once the…
Un metodo per il progetto di massima di dissipatori isteretici e viscosi e applicazione a casi concreti
2009
TELAI DISSIPATIVI IN ACCIAIO PER LA MITIGAZIONE DEL RISCHIO SISMICO DI SISTEMI MURARI DI INTERESSE STORICO
2011
Il lavoro riguarda la possibilità di impiego di dispositivi fluido viscosi per il miglioramento o l’adeguamento sismico di edifici in muratura appartenenti all’edilizia storico monumentale. In questi casi, per evidenti motivi legati alla tutela dei valori architettonici dell’opera, non è possibile adottare interventi di tipo tradizionale per il rinforzo statico della muratura (FRP, CAM). Una soluzione alternativa, di maggiore efficacia, può essere ottenuta attraverso l’inserimento di dispositivi fluido viscosi, con il risultato di aumentare la capacità dissipativa della struttura con conseguente riduzione della domanda di spostamento. A riguardo, si descrive una procedura, già proposta da a…
Interventi di miglioramento e adeguamento sismico di edifici in c.a. dell’Azienda Ospedaliera Universitaria Policlinico “Paolo Giaccone” di Palermo
2008
The paper shows the results of an experimental investigation on the behaviour of compressed concrete columns subjected to the overcoring technique. Extraction of cylindrical concrete cores in perpendicular direction to the column surface, was achieved by rotary drilling using a diamond tipped hollow barrel. Core is gradually isolated from the stress field in the surrounding concrete and at every advancing step the re-equilibrium deformation response is measured by means of four strain-gauges, placed on its external surface and near the hole. Finally the original stress state is computed in the elastic phase on the basis of recorded strains, knowing the elastic properties of concrete and by …
Cavity losses for the dissipative Jaynes–Cummings Hamiltonian beyond rotating wave approximation
2007
A microscopic derivation of the master equation for the Jaynes-Cummings model with cavity losses is given, taking into account the terms in the dissipator which vary with frequencies of the order of the vacuum Rabi frequency. Our approach allows to single out physical contexts wherein the usual phenomenological dissipator turns out to be fully justified and constitutes an extension of our previous analysis [Scala M. {\em et al.} 2007 Phys. Rev. A {\bf 75}, 013811], where a microscopic derivation was given in the framework of the Rotating Wave Approximation.