Search results for " Push."

Assessment of push-out test response of hybrid steel trussed-concrete beams by FE model

2013

Aiming to investigate the truss-concrete stress transfer mechanism in Hybrid Steel Trussed-Concrete Beams (HSTCBs), a three-dimensional nonlinear FE model is developed. The constitutive laws of the steel composing the plates and the bars is modeled by means of a quadri-linear law, while the concrete behavior is defined by means of a Concrete Damaged Plasticity (CDP) model, suitable for modeling concrete and brittle materials. The CDP model uses the concept of isotropic damaged elasticity in combination with isotropic tensile and compressive plasticity and is able to properly account for the concrete confinement effect. Two main failure mechanisms are considered, namely the tensile cracking …

Evaluation of the shear connection strength of precast hybrid steel-trussed-concrete composite beams

2015

In last decades, significant efforts have been carried out by the scientific community to evaluate the main technical issues of Hybrid Steel-Trussed-Concrete beams, investigating both the first opera-tive phase, i.e. before the concrete casting, when only the bare truss works, and, the second phase, i.e. after the concrete curing, when the beam works as a composite element. In the present study, the attention is focused on the evaluation of the shear strength of the connection between the bottom plate of the steel truss and the concrete core proposing a mechanical model able to predict its ulti-mate resistance. The proposed mechanical formulation is mainly based on the extension of existing…

Tecniche di analisi statica non lineare multimodale per strutture intelaiate

2015

Viene presentata una panoramica delle più efficienti tecniche di analisi statica non lineare, evidenziando i progressi fatti nella formulazione di procedure con profili di carico adattivi multimodali, finalizzati alla valutazione della risposta di strutture a comportamento fortemente non lineare. Vengono poi presentate le diverse procedure che consentono di analizzare il comportamento di strutture irregolari in altezza o con grandi periodi di vibrare, nella quale la risposta è fortemente influenzata dai modi superiori. In quest’ambito viene evidenziato il ruolo della procedura Modal Pushover Analysis, che risulta fra le più efficienti nel riprodurre il comportamento di strutture fortemente …

Definizione di Mappe di Vulnerabilità Sismica per le Aree Mediterranee Transfrontaliere: Il caso di Lampedusa

2015

La possibilità di individuare e quantificare le principali criticità legate ad eventi catastrofici naturali su un territorio, consente di pianificare strategie e interventi adeguati da parte degli organismi di Protezione Civile coinvolti in emergenze locali e internazionali. Il rischio sismico dipende soprattutto dalla vulnerabilità degli edifici appartenenti alle aree urbane. La conoscenza degli scenari di rischio è dunque fondamentale per pianificare e gestire azioni di assistenza in caso di emergenza e non può prescindere dalla quantificazione e localizzazione della vulnerabilità sismica. Il presente studio propone una procedura per la definizione di mappe di vulnerabilità sismica in ter…

Travi reticolari miste- Problemi locali nella trasmissione degli sforzi

2009

Experimental test results on the local behavior of the typical Italian typology of hybrid steel-to-concrete beam are presented and discussed in order to provide insight on transfer mechanism between different components of the beam. Preliminarily, in order to investigate on the bearing capacity of the welding and on the local instability problems that can arise in the trusses before concrete casting, tensile tests on specimens reproducing different types of welded joints, and push-out tests on bare specimen have been performed. Then, the transfer mechanism between steel trusses and concrete is investigated by means of push-out tests carried out also in displacement controlled mode. Results …

Non-linear Correlation Coefficients for pushover analysis

2013

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…

Seismic response of steel frames with reduced beam sections

2003

This study concerns the effectiveness of weakening on the beams of fully and partially restrained connection steel frames in order to locate plastic hinges far from the joints. Two types of non-linear analysis, for geometry and constitutive law are developed: static pushover analysis, in which the structure is subjected to constant vertical loads and to horizontal loads linearly increasing up to collapse; and incremental dynamic analysis, in which the structure is subjected to uniformly scaled ground motions. Applications for four-bay frames with three and nine stories designed according to the EC3 code and for Italian 1st-category seismic areas are developed in order to evaluate the influe…

Prove di Push-Out su travi reticolari miste

2008

Results of push-out experimental tests on typical italian typology of hybrid steel-to-concrete beam are presented and discussed in order to provide insight on transfer mechanism between concrete and steel truss. Two specimens of a shallow beam are tested and experimental relationships between interaction force, total slip and strain in truss elements are shown; moreover, behaviour of specimens at failure is discussed.

The Lean Urban Policies’ Design A values-centered method for sustainable urban planning.

In these past years, the necessity and urgency has emerged for policies tied to an alternate development to be efficiently applied, and not limited to single operations. The policies must be defined by a clear and effective method of action.
 Starting by investigating what are the relationship among human being, built environment and natural sources, in fact, we think it is possible to enrich the sustainable urban planning policies with new contents and possibly, new tools. By describing the frame, the objective is to define the most effective method, to be able to convey an effective project action and governance for the territory, to achieve predefined social and energy based objectives. …

L’exemplum del Dinomenide Gelone tra memoria civica e storiografica

2015

La storia della Sicilia greca è scandita, nei suoi momenti chiave, dalla persistente presenza dell’immagine del Dinomenide Gelone. Questo lavoro analizza le valenze paradigmatiche assunte dalla sua figura nella memoria civica siracusana e nella produzione storiografica; inoltre ricostruisce le dinamiche politiche che hanno spinto i principali tiranni siracusani (da Dionisio I a Ierone II) a stabilire un confronto con Gelone. Il suo exemplum è utilizzato per legittimare azioni politiche e impegno antipunico; particolare attenzione è posta alla Biblioteca storica di Diodoro Siculo e al ruolo che in essa assume la figura del Dinomenide; in relazione a questi aspetti l’opera dell’Agirinense sem…