Search results for "beam"

Comportamento flessionale di nodi esterni in calcestruzzo fibrorinforzato

2010

A softened strut-and-tie macro model able to reproduce the flexural behavior of external beam-tocolumn joints with the presence of horizontal and vertical steel bars, including softening of compressed struts and yielding of main and secondary steel bars, is presented, to be used for the pushover analysis. The model proposed is able to calculate also the flexural response of fibrous reinforced concrete (FRC) beam-to-column sub-assemblages in term of a multilinear load-deflection curves. The model is able to take into account of the tensile behavior of main bars embedded in the surrounding concrete and of the softening of the compressed strut, the arrangement and percentage of the steel bars,…

Experimental characterization of friction properties of materials for innovative beam-to-column dissipative connection for low-damage RC structures

2023

Low-damage design of structures in seismic-prone areas is becoming an efficient strategy to obtain "earthquake-proof" buildings, i.e. buildings that, even in the case of severe seismic actions, experience a low or negligible amount of damage. Besides the safeguard of human lives, this design strategy aims also to limit the downtime of buildings, which represents a significant source of economic loss, and to ensure an immediate occupancy in the aftermath of an earthquake. In this context, focusing on moment-resisting frames (MRFs), several solutions have been developed for the beam-to-column connections (BCCs) of steel and precast/prestressed concrete structures, but very few for cast-in-sit…

Indagine sperimentale su nodi di tralicci in acciaio di travi reticolari miste

2009

Results of experimental tests on welded joints of steel truss of encased composite steel-concrete beams are presented. The welding of the inclined web bars to top bars, both of steel type B450C, and to bottom steel plate, the latter made of S355 steel type, are tested. Two analytical expressions for prediction of welding strength are derived: the one based on a resistance criterion and the other based on a limit domain of the welding section. Guidelines for choosing the effective dimensions of the fillet weld, necessary to determine the strength, are provided. A high precision digital scanner is used to validate the suggested guidelines to determine the geometrical characteristics of the fi…

ANALISI TEORICO-SPERIMENTALE DEL COMPORTAMENTO A TAGLIO DI TRAVI PREFABBRICATE RETICOLARI MISTE

2014

An experimental campaign of three-point bending tests on specimens of Hybrid Steel Trussed Concrete Beams (HSTCBs) is presented. The scope of the experiments is the evaluation of the shear strength in the structural typology object of study. Two series of specimens are tested, subjected to positive and negative bending moment, respectively, with the aim to reproduce, in the first case, the condition in the midspan of a beam belonging to a framed structure and, in the second case, the behavior of the beam next to the column where the sign of the bending moment is reversed. The obtained experimental results are interpreted by means of an analytical model for the prediction of the shear resist…

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 …

Sistema di dissipazione sismica per strutture edili

2022

Innovative connections for steel-concrete-trussed beams: a patented solution

2023

The most recent design strategies welcome the adoption of innovative techniques for seismic energy input mitigation, aiming to achieve high dissipation capacity, prevent the structure from collapse and ensure the serviceability of the construction. Friction damper devices have been widely adopted in framed steel structures for decades, while their introduction in different structural types is still under investigation. This paper presents the outcomes of innovative research supported by the industry and conducted on beam-to-column connections of RC structures in which the beams are Hybrid Steel-Trussed Concrete Beams (HSTCBs) and the columns are classical RC pillars. An innovative solution,…

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…

Finite element modeling of the shear behavior of hybrid steel trussed concrete beams

2015

The development and calibration of a three-dimensional (3D) nonlinear Finite Element (FE) model is presented with the aim of investigating the shear behavior of steel-concrete composite beams realized with a steel truss embedded into a concrete core and named Hybrid Steel Trussed-Concrete Beams (HSTCBs). The model is calibrated on the results of a reference experimental campaign of three-point bending tests on HSTCBs realized at the Laboratory of Structures of the University of Palermo. The actual behavior at the steel-concrete interface has been introduced in the model through the implementa-tion of a cohesive constitutive relationship. Furthermore, the damaged plasticity of concrete has b…

Shear-flexure interaction of RC elements strengthened with FRP sheets

2005

An approximate physical model for evaluation of the M-V interaction resistance domains for concrete elements strengthened with FRP sheets is presented. The reliability of the model in predicting flexureshear capacity is verified by a comparison with the results of several experimental tests.