0000000001211976
AUTHOR
Gabriele Testa
Non-linear Correlation Coefficients for pushover analysis
Aiming to put forward an improvement on Multimodal Pushover Analysis, a modified version of the modal correlation rule that takes into account the non-linear behavior of structures is proposed. The modification is primarily based on using the correlation coefficients consistent with the mechanical and dynamical properties of the hysteretic oscillators utilized in the MPA method, i.e. determined taking into account the second order statistics pertinent to the non-linear oscillators. Initially, the new correlation coefficients are evaluated by Monte Carlo Simulations (MCS), assuming a spectrum-compatible representation of the seismic input. The results of a large numerical parametric analysis…
Un criterio di selezione dell’input sismico per l’analisi dinamica non lineare delle strutture
Viene proposto un metodo di selezione di accelerogrammi naturali da impiegare nell’analisi dinamica non lineare al passo. Allo scopo di valutare la capacità dei parametri di intensità sismica di rappresentare il potenziale di danneggiamento del sisma, sono stati analizzati gli spettri delle correlazioni tra i parametri di intensità sismica che caratterizzano le registrazioni accelerometriche ed i parametri cinematici, energetici e di danno rappresentativi della risposta strutturale di un sistema ad un grado di libertà. In tale ambito, è stato definito un nuovo parametro di intensità sismica in forma integrale, l’Accelerazione di Picco Efficace per la Struttura (SEPA - Structure Effective Pe…
Comparison of fully non-stationary artificial accelerogram generation methods in reproducing seismicity at a given site
Abstract Seismic input modelling is a crucial step when Non-Linear Time-History Analyses (NLTHAs) are performed, the seismic response of structures being highly responsive to the input employed. When natural accelerograms able to represent local seismicity are not available, the use of generated accelerograms is an efficient solution for input modelling. The aim of the present paper is to compare four methods for generating fully non-stationary artificial accelerograms on the basis of a target spectrum, identified using seven recorded accelerograms registered in the neighbourhood of the construction site during a single event, assumed as target accelerograms. For each method, seven accelero…
Non linear and linearized combination coefficients for modal pushover analysis
Current design practice and seismic codes tend to assess seismic demand of buildings by Non linear Static Analysis (NSA), based on the evaluation of the pushover curve. Earlier non-linear static analysis procedure estimate the response peak value by evaluating the push-over curve adopting a distribution of invariant forces proportional to the fundamental vibration mode. In order to include the effect of higher modes several multimodal push-over analysis procedures were proposed in literature. In In the most famous of these, namely Modal Pushover Analysis (MPA), nodal response peak values are obtained by combination of "modal" responses by the traditional SRSS or CQC methods: the use of the …
COMPORTAMENTO CICLICO DI PANNELLI SOTTILI IN ACCIAIO
abstractita La memoria riporta i risultati di indagini sperimentali su pareti sottili in acciaio sottoposte ad azioni cicliche, ponendo in risalto le capacità dissipative. Le prove sono state condotte presso il laboratorio DISMAT di Canicattì (AG)su modelli in scala 1:2. I risultati evidenziano le riserve di resistenza dei pannelli in fase post critica. Results of experimental tests on Steel Plate Shear Wall (SPSW) placed in steel frames subjected to cyclic actions are presented, stressing the dissipative capacity of the system. The tests were performed at the DISMAT laboratory in Canicattì (AG) on scale specimens. The surrounding frame is made by HEA 160 beam and columns with pinned joint,…
Proposal of a Selection Criterium of Natural Accelerograms for NLRHA
A selection criterion to obtain different sets of accelerograms, all of them satisfying the spectrum compatibility criteria imposed by the codes, that enable a reliable assessment of the seismic demand for a given structure is proposed. The formulation is based on a preliminary evaluation of correlations among Intensity Measure parameters for ground motion and cinematic, energetic and damage parameters describing structure non linear responses. To this aim, a modified expression of the Effective Peak Acceleration EPA* is proposed, defined over the range of structure fundamental period referring to undamaged and damaged model. The analyses are carried out analyzing the response of a three pl…