Search results for " Finite Element"

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…

COMPRESSIVE BEHAVIOR OF CONCRETE COLUMNS AXIALLYLOADED BEFORE CFRP-WRAPPING. REMARKS BY EXPERIMENTALNUMERICAL INVESTIGATION

2018

Strengthening of existing concrete columns with Fiber Reinforced Polymers (FRP) results generally in a satisfactory structural member improvement in terms of load and strain capacity. A reliable prediction of the capacity obtained by these reinforcement strategies requests a proper knowledge of the load-strain response of the confined concrete elements. However, so far, the available design methods and technical codes do not consider the effect of the possible presence of service loads at the moment of application of the reinforcement, and therefore, the compressive behavior of the concrete confined under preload is still unclear. In this paper, the effect of sustained loads on the compress…

Simplified equivalent finite element modelling of concrete-filled steel tubular K-joints with and without studs

2022

Concrete Filled Steel Tubular (CFST) K-joints employed for truss structures gained high interest in the last years due to their widespread use in engineering practice. The overall performances of these joints can be efficiently improved by using steel studs welded in the inner surface of the steel chord filled with the concrete, avoiding punching shear failure, and improving the overall strength and ductility. However, a reliable prediction of the structural behavior of the joints is outmost of importance for the assessment of the capacity of new and existing structures, and there are no standardized design methods nowadays. In this paper, the structural performances of CFST K-joints with a…

A numerical study on the effect of the interface material model on the tensile behaviour of FRCM strips

2019

Fibre Reinforced Cementitious Matrix (FRCM) composites are becoming increasingly popular for strengthening masonry structures for which the compatibility of the inorganic matrix with the chemical and physical properties of the support makes it advantageous to adopt such systems. However, despite the large use of FRCMs for strengthening applications, the characterization and modelling of the mechanical response in tension of these systems is an open issue. In fact, the constitutive tensile law of the composite shows to be affected by different variables, such as the clamping system adopted during tensile test, the gauge length used for recording strains, the monitoring of the number of yarns…

A two-node finite element for linear magneto-electric laminated timoshenko beams

2012

A new finite element is presented for linear magnetoelectric straight laminated beam subject to the assumptions of quasi-steady electromagnetic state. The mechanical model is based upon Timoshenko beam theory to account for shear deformation influences. The electromagnetic stacking sequence is proved to enter the equivalent elastic problem by affecting both the stiffness properties of the beam, in terms of axial and flexural coupling, and by modifying the mechanical boundary conditions as distributed loads. Shape functions are first written for the generalized beam mean-line kinematical quantities in such a way the obtained strain field fulfills the homogeneous governing equations of the eq…