caa a22 4500 445847220 CHVBK 20180317145402.0 cr unu---uuuuu 170323e20111001xx s 000 0 eng 10.1007/s10518-011-9291-1 doi (NATIONALLICENCE)springer-10.1007/s10518-011-9291-1 The relevance of energy damping in unreinforced masonry rocking mechanisms. Experimental and analytic investigations [Elektronische Daten] [Luigi Sorrentino, Omar AlShawa, Luis Decanini] Existing unreinforced masonry buildings frequently suffer out-of-plane local collapse mechanisms when undergoing earthquake ground motion. The energy damping that occurs during the motion, due to impacts of a wall against the foundation or against other walls, is a relevant parameter on the response. An experimental investigation has been carried out to estimate the dissipation of kinetic energy that takes place during free oscillations. Restraint conditions allow for two-sided rocking (wall resting on a foundation) and one-sided rocking (wall resting on a foundation adjacent to transverse walls). Five specimens have been tested, modelling walls acted out-of-plane (façades). When one-sided rocking is under consideration, different depths of the contact surface between façade and transverse walls are considered. In the case of two-sided rocking, the experimental coefficient of restitution is slightly lower than the analytic coefficient. In the case of one-sided rocking, an analytic formulation is proposed and this is compared against experimental data. Although the coefficient of restitution of one-sided rocking is less than half that of two-sided rocking, it is not equal to zero. Thus, it cannot induce a sudden stop of the motion. Hence, nonlinear time history analyses performed under this assumption may prove unsafe. Moreover, a comparison has been carried out between overturning maps, induced by twenty natural accelerograms, computed for the analytic coefficient of restitution and those computed for the experimental coefficient of restitution. The increased energy dissipation reduces the frequency of overturning and causes a more regular behaviour. Springer Science+Business Media B.V., 2011 Impulsive energy dissipation nationallicence Experimental coefficient of restitution nationallicence Analytic coefficient of restitution nationallicence Two-sided rocking nationallicence One-sided rocking nationallicence Sorrentino Luigi Dipartimento di Ingegneria Strutturale e Geotecnica, Università degli Studi di Roma "La Sapienza”, via Antonio Gramsci 53, 00197, Rome, Italy aut AlShawa Omar Dipartimento di Ingegneria Strutturale e Geotecnica, Università degli Studi di Roma "La Sapienza”, via Antonio Gramsci 53, 00197, Rome, Italy aut Decanini Luis Dipartimento di Ingegneria Strutturale e Geotecnica, Università degli Studi di Roma "La Sapienza”, via Antonio Gramsci 53, 00197, Rome, Italy aut Bulletin of Earthquake Engineering Springer Netherlands 9/5(2011-10-01), 1617-1642 1570-761X 9:5<1617 2011 9 10518 https://doi.org/10.1007/s10518-011-9291-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10518-011-9291-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sorrentino Luigi Dipartimento di Ingegneria Strutturale e Geotecnica, Università degli Studi di Roma "La Sapienza”, via Antonio Gramsci 53, 00197, Rome, Italy aut NATIONALLICENCE 700 1- AlShawa Omar Dipartimento di Ingegneria Strutturale e Geotecnica, Università degli Studi di Roma "La Sapienza”, via Antonio Gramsci 53, 00197, Rome, Italy aut NATIONALLICENCE 700 1- Decanini Luis Dipartimento di Ingegneria Strutturale e Geotecnica, Università degli Studi di Roma "La Sapienza”, via Antonio Gramsci 53, 00197, Rome, Italy aut NATIONALLICENCE 773 0- Bulletin of Earthquake Engineering Springer Netherlands 9/5(2011-10-01), 1617-1642 1570-761X 9:5<1617 2011 9 10518 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer