1,721,137 research outputs found
Rapporto dei danni provocati dell'evento sismico del 6 aprile sugli edifici scolastici del centro storico dell'Aquila. Report RELUIS, Rete dei Laboratori Universitari di Ingegneria Sismica, 2009
No full textCyclic behaviour of uncorroded and corroded steel reinforcing bars
No full textIn the present work the results of a wide experimental test campaign on steel reinforcing bars, including monotonic tensile and low-cycle fatigue tests, the last ones able to reproduce the stress-strain condition induced by seismic events, are presented. The main aim of the research work consists in the analysis of the combined effects of seismic action and aggressive environmental conditions on the ductile behaviour of steel reinforcements: as a consequence, mechanical tests were executed also on samples previously subjected to exposure in salt spray chamber, evaluating the residual mechanical properties and dissipative capacity
Experimental and numerical assessment of EBF structures with shear links
No full textEccentrically braced frames (EBF) represent an optimal structural solution for seismic prone areas, being able to provide high dissipative capacity and good elastic stiffness, to withstand strong seismic events without significant loss of bearing capacity and to avoid damage to non-structural elements in case of low and moderate earthquakes. The accurate knowledge of the cyclic behaviour of the dissipative links, characterizing the whole performance of EBFs, is required to optimize the structural properties and to refine the design techniques adopted for multi-storey buildings’ analysis. Reliable numerical models for the links, at the same time requiring a limited computational effort, are then needed. The present work shows the results of a wide experimental test campaign executed on real-scale one storey/one bay frames with horizontal and vertical links, together with the elaboration of a simple semi-analytical model for the quick representation of the cyclic behaviour of shear links
Comportamento sismico di giunti trave-colonna a parziale ripristino di resistenza per strutture composte acciaio calcestruzzo
No full textSeismic performance of steel braced frames equipped with dissipative replaceable components
No full textThe structural performance of steel braced frames equipped with a new typology of dissipative replaceable components (called DRBrC) is analyzed and compared to the one of a traditional Concentrically Braced Frame (CBF) with diagonal-tension-only braces, highlighting pros and cons of the different solutions. The main benefit of the proposed system lies in the easy replacement of the damaged dissipative components after the earthquake, allowing to speed up retrofit operations without stopping the activities inside the building. The results of low-cycle assessment and life cycle cost analysis performed in the framework of the European research project DISSIPABLE confirmed the economic and environmental convenience of the system for repairing operations after seismic events. In the present work, two case study buildings, owing the same geometry and designed for the same loads with and without DRBrC devices, are analyzed and compared in terms of overall seismic performance, relevant parameters versus Intensity Measure (IM) indicators and fragility curves. An in-depth dissertation about design criteria, numerical modelling techniques and analysis procedures in the nonlinear field to be used for the DRBrC frames is provided
An innovative solution for hybrid steel-glass self-bearing modular systems
No full textThe performance of a quadrangular steel-glass self-bearing system for roofs and facades is analyzed through numerical simulations and experimental tests. The system is characterized by a double deformed configuration obtained using cold bending procedure, applying displacements in correspondence of two opposite corners and avoiding spring back phenomena through the steel frame. Nonlinear analyses were executed to simulate the assembly process of the system and to determine the load bearing capacity of the deformed system under vertical loads. Experimental tests were executed allowing to validate the model and to assess the behaviour of corners. A simplified resistance domain is finally proposed
Mechanical performance of steel reinforcing bars in uncorroded and corroded conditions
Full text linkThe paper presents data coming from a wide experimental test campaign executed on different typologies of steel reinforcing bars representative of the actual European production scenario. Tensile and low-cycle fatigue tests have been executed to assess the mechanical performance of reinforcing bars under monotonic and cyclic/seismic conditions. The effects of exposure to aggressive environmental conditions have been reproduced through accelerated salt-spray chamber. Residual mechanical performance of corroded specimens has been analyzed as function of corrosion indicators such as mass loss and necking
Evaluation of structural safety and seismic vulnerability of historical masonry buildings: studies and applications in the Tuscany Region
Full text linkRecent earthquakes in Italian regions evidenced the high vulnerability of historical masonry existing buildings: severe damages were revealed in structural and not structural elements with the following loss of lives and of significative examples of the Italian architectural tradition, often requiring a strong financial effort to be carried back to their ancient brightness. The majority of the Italian buildings' heritage is made up of masonry constructions with high architectural, historical and monumental impact, enlarged over the centuries without an organized scheme and consequently characterized by structural and not structural problems often increased by the loss of an accurate maintenance. The Italian Standards for Constructions and the guidelines provided by the Ministry for Infrastructures for the evaluation and reduction of seismic risk on historical heritage pay a lot of attention towards the vulnerability analysis of existing buildings, necessary for the elaboration of a project providing higher level of structural static and seismic safety without deleting the original nature of the building. In the present work, the structural analyses of two historical masonry buildings, Palazzo La Sapienza in Pisa and Palazzo Ducale in Massa are presented
Influence of low-cycle fatigue and corrosion phenomena on the structural behaviour of steel reinforcing bars
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