Search results for " Finite Element model"

Analytical prediction of the shear connection capacity in composite steel–concrete trussed beams

2016

Steel–concrete trussed composite beams are a particular types of composite girders constituted by a steel truss embedded in a concrete core. The truss is typically composed by a steel plate or a precast concrete slab working as bottom chord while coupled rebars are generally used to form the upper chord. Moreover, a system of ribbed or smooth steel rebars welded to the plate and forming the diagonals of the truss, works as web reinforcement. In the present study, the attention is focused on the evaluation of the shear resistance of the connection between bottom steel plate (the bottom chord) and concrete core through the diagonal bars of the truss developing a mechanical model able to accou…

Analysis of Joint Quality along Welding Plane

2009

Porthole die extrusion is an always more important process for industrial applications. It is, however, characterized by a considerable complexity; in fact, different parameters have to be carefully set for improving the final part. A critical zone that strongly influences the goodness of the extruded component is the so called “welding plane”. It is the junction area where material flows converge inside the welding chamber. The variables that have to be controlled for improving the material characteristics in this zone are the effective stress, the pressure and the time that the material takes to cross the welding chamber. Moreover, material temperature is another fundamental issue that in…

Nonlinear Analysis of Beams Reinforced in Shear with Stirrups and Steel Fibers

2012

The modified compression field theory (MCFT) and the disturbed stress field model (DSFM) are often used to predict the nonlinear behavior of reinforced concrete structures. This study presents several extensions of the MCFT and DSFM to the case of high-strength steel fiber-reinforced concrete beams subjected to transverse loads. Experimental four-point bending tests were conducted on 12 concrete beams with a different percentage of fibers and/or stirrups. To validate the updates introduced in the analytical models, numerical analysis was performed using nonlinear finite element software. Modeling of the post-peak softening branch of the tensile and compressive constitutive curves of fibrous…

Dissipative connections of rc frames with prefabricated steel-trussed-concrete beams

2020

In the last thirty years, Hybrid Steel-Trussed Concrete Beams (HSTCBs) have been widely used in civil and industrial constructions and, therefore, their mechanical performance must be evaluated with the aim of guaranteeing adequate dissipation of the seismic energy particularly in the beam-to-column joints. However, one of the most frequent peculiarities of HSTCBs is that of using their own steel joist to cover large spans with reduced depth and, in the case of traditional beam-to-column connections, this requires large amount of steel reinforcement inside the panel zone, often made with large diameter rebars. These characteristics make both the panel zone and the beam end potentially vulne…

Compressive response of concrete columns under service conditions strengthened by confining devices: from the local to the global behavior.

Il rinforzo di colonne in calcestruzzo armato tramite materiali polimerici fibrorinforzati (FRP) o tramite incamiciature in acciaio conferisce agli elementi strutturali degli edifici esistenti un elevato incremento di capacità portante e deformativa grazie alle proprietà dei materiali che svolgono la funzione di confinamento. Conoscere adeguatamente le proprietà meccaniche degli elementi in calcestruzzo confinato risulta di fondamentale importanza nell’ambito di un progetto di sistemi di rinforzo strutturale. Tuttavia, le normative attualmente vigenti non forniscono prescrizioni su come tenere in considerazione la presenza dei carichi di esercizio sugli elementi strutturali al momento dell’…

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,…

Influence of wall-to-floor connections and pounding on pre- and post-diction simulations of a masonry building aggregate tested on a shaking table

2023

AbstractThis paper presents numerical simulations within the frame of the project SERA—AIMS (Seismic Testing of Adjacent Interacting Masonry Structures). The study includes blind pre-diction and post-diction stages. The former was developed before performing the shaking table tests at the laboratory facilities of LNEC (Lisbon), while the latter was carried out once the test results were known. For both, three-dimensional finite element models were prepared following a macro-modelling approach. The structure consisted of a half-scaled masonry aggregate composed by two units with different floor levels. Material properties used for the pre-diction model were based on preliminary tests previou…

Simulation of blind pre-diction and post-diction shaking table tests on a masonry building aggregate using a continuum modelling approach

2023

AbstractMasonry buildings of historical centres are usually organized within aggregates, whose structural performance against seismic actions is challenging to predict and constitutes still an open issue. The SERA—AIMS (Seismic Testing of Adjacent Interacting Masonry Structures) project was developed to provide additional experimental data by testing a half-scale, two-unit stone masonry aggregate subjected to two horizontal components of dynamic excitation. In this context, this paper investigates the reliability of the modelling approach and the assumptions adopted to generate a three-dimensional continuum finite element model. The work involves two stages, namely a blind pre-diction and a…

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…

Numerical analysis of the effects of PBO-FRCM confinement on RC columns

2018

This paper presents a finite element (FE) analysis on the behavior of reinforced concrete (RC) squared and rectangular columns strengthened by PBO-FRCM, under axial force and bending moment. The modeling technique adopted for the compressive behavior of confined concrete is previously validated developing FE models for specimens of plain concrete wrapped by PBO-FRCM and comparing the numerical results with those obtained by experimental tests on squared and rectangular confined columns. Then, the model of the RC element is developed reproducing the load condition of columns in a MRF loaded by horizontal forces with constant axial load applied to the pillar during the analysis. The numerical…