Search results for "Shear"
showing 10 items of 804 documents
EXPERIMENTAL INVESTIGATION ON R.C. BEAMS RETROFITTED IN FLEXURE AND SHEAR BY PRETENSIONED STEEL RIBBONS
2014
The experimental results of three and four point loading tests on reinforced concrete beams strengthened by angles and/or pre-stressed stainless steel ribbons (CAM system) are presented. The stainless steel prestressed ribbons play the role of adjunctive transversal reinforcement as well as confine the structural element. Six flexural critical beams and nine shear critical beams were tested. In the first group four beams were retrofitted with bottom stainless steel angles and transversal ribbons, with two different spacing. In the second group three specimens were retrofitted by wrapping the beam with the ribbons, while three specimens were strengthned by perforation of the beam beneath the…
COMPORTAMENTO CICLICO DI PANNELLI SOTTILI IN ACCIAIO
2013
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,…
Flexural and Shear Resistance of High Strength Concrete Beams
2014
In the present paper, an analytical model is proposed that is able to determine the shear resistance of high strength reinforced concrete beams with longitudinal bars, in the presence of transverse stirrups. The model is based on the evaluation of the resistance contribution due to beam and arch actions. For the resistance contribution of the main bars in tension the residual bond adherence of steel bars and the crack spacing of R.C. beams are considered. The compressive strength of the compressed arch is also verified by taking into account of the biaxial state of stresses. The model was verified on the basis of experimental data available in the literature and it is able to include the fo…
Modello Esplicito Per La Resistenza A Taglio Di Travi In C.A. Con Armature Trasversali Disposte Secondo Due Giaciture
2016
An analysis oriented mechanical model for shear strength evaluation of rc beams with transversal reinforcement with two different inclination, that required a numerical analysis, is tuned into a design oriented analytical model that can be handy utilized for practical design.
Experimental investigation on high-strength fibre-reinforced concrete beams subjected to bending and shear
2008
The results of an experimental campaign carried out on a number of high-strength concrete beams loaded in 4-point bending are presented in this paper, where the roles of the both steel hooked fibres and the transverse reinforcement are investigated, for different values of the shear span. All tests were displacement-controlled. The results – mostly in terms of load-deflection curves – confirm what is well known in the literature, that an adequate amount of steel fibres can turn a brittle shear-type failure into a ductile flexural-type failure, to the advantage of the ultimate bearing capacity in flexure and shear, that can be fully exploited without increasing the transverse reinforcement. …
Comparative analysis of shear resisting models for hybrid steel trussed concrete beams
2018
The hybrid steel trussed concrete beams represent a structural solution widely adopted in the industrial constructions thanks to the numerous advantages due to their use, such as economic convenience, high performances and constructional speed de-riving from the partial prefabrication process and from the self load-carrying capacity of the beam in the first operative phase, prior to the in-site casting of concrete. The hybrid steel trussed concrete beams examined in the present study are constituted by two prin-cipal components, i.e. a steel joist with inclined rebars, realized in industry, which is welded to a smooth steel plate and then embed-ded within the concrete material cast in situ.…
Advances in experimental characterization and modelling of FRCM composites for structural retrofitting
2023
Questa tesi presenta i risultati di una campagna sperimentale incentrata sulla caratterizzazione della trazione dei basalt e glass FRCM e della caratterizzazione del legame di aderenza composito-Calcarenite. Il lavoro sperimentale è completato dalla proposta di due modelli numerici sia per prove di trazione che per quelle di aderenza. L'indagine sperimentale è stata condotta considerando l'influenza di diversi rinforzi, matrici e metodi di prova. I risultati sperimentali consentono di valutare l'effetto della malta sulle curve sforzo-deformazione, la resistenza, la duttilità e le modalità di crisi. Inoltre, la tesi fornisce un importante contributo per valutare l'influenza di diversi metodi…
Numerical Modelling of the Constitutive Behaviour of FRCM Composites through the Use of Truss Elements
2023
The modeling of the mechanical behavior of Fabric Reinforced Cementitious Matrix (FRCM) composites is a difficult task due to the complex mechanisms established at the fibre-matrix and composite-support interface level. Recently, several modeling approaches have been proposed to simulate the mechanical response of FRCM strengthening systems, however a simple and reliable procedure is still missing. In this paper, two simplified numerical models are proposed to simulate the tensile and shear bond behavior of FRCM composites. Both models take advantage of truss and non-linear spring elements to simulate the material components and the interface. The proposed approach enables us to deduce the …
SHEAR STRENGTH DEGRADATION DUE TO FLEXURAL DUCTILITY DEMAND IN R.C. ELEMENTS
2014
A proposal is formulated that allows to evaluate the residual shear strength of reinforced concrete columns and beams for an assigned flexural ductility demand by limiting the range of the deviation angle between the inclinations of the yield and the crack lines. In order to take into account the degradation due to cyclic loads, the reduction of the range of the deviation angle is related to the value of cinematic ductility
STUDIO NUMERICO DELL'EMODINAMICA IN PAZIENTI CON DISSECAZIONE AORTICA DI TIPO B
2013
The development of type B aortic dissection (AoD) is caused by altered haemodynamic forces exerted on false and true lumina of dissected aorta. This work aims to study haemodynamic and morphological proprieties, which influence the progression or stability of type B AoD. Computational fluid-dynamic analyses were performed on three patients with type B AoD, whose two presented an aneurysm evolution and one presented no further complication connected with dissection. Blood flow features showed that the true lumen flow was laminar and uniform while false lumen flow lost the laminar characteristic with consequent vorticity formation. The entry point zone proximal to the aortic arch showed both …