Three-field mixed formulation for the non-linear analysis of composite beams with deformable shear connection

A three-eld mixed nite element is proposed for the non-linear analysis of composite beam with deformable shear connection. The formulation considers the non-linear behaviour of materials and shear connectors. The established mixed element is compared to the locking-free displacement element from which it derives and to a rened locking-free displacement element previously tested by the authors. In order to evaluate the way to better improve the solution in the non-linear range (three-eld mixed formulation or rened displacement formulation), numerical applications are performed using, as working example, a steel- oncrete cantilever, representing a di3cult test for composite beam elements

Lezioni di Tecnica delle Costruzioni

Il presente testo “Lezioni di Tecnica delle Costruzioni” ha l’obiettivo di introdurre principi e metodologie per il progetto e la verifica degli elementi strutturali in acciaio e in calcestruzzo armato in accordo con la normativa italiana

Talking about Radar interferometry

In the last two decades the use of radar for the monitoring of different phenomena as landslides, glaciers and snow-covered areas, has been rapidly increasing. Synthetic Aperture Radar (SAR) imagery from satellite is a reliable and well known tool for many Remote Sensing users fully integrated in Copernicus activities. More recently also Ground Based radar interferometers have been available for terrestrial applications. In these two lectures the listener is introduced to the basic principles governing some of the applications, to achieve a basic understanding of the physical mechanisms which govern these microwave-based observations. Examples of applications in Geophysics and Civil Engineering are also shown aiming to provide a practical and exhaustive view to users and researchers. In particular, the use of Real Aperture Radar (RAR) Aperture demonstrated a consolidated technique for estimating the dynamical behaviour of civil structures

Evolutionary Optimization for Active Debris Removal Mission Planning

Active debris removal missions require an accurate planning for maximizing mission payout, by reaching the maximum number of potential orbiting targets in a given region of space. Such a problem is known to be computationally demanding and the present paper provides a technique for preliminary mission planning based on a novel evolutionary optimization algorithm, which identifies the best sequence of debris to be captured and/or deorbited. A permutation-based encoding is introduced, which may handle multiple spacecraft trajectories. An original archipelago structure is also adopted for improving algorithm capabilities to explore the search space. As a further contribution, several crossover and mutation operators and migration schemes are tested in order to identify the best set of algorithm parameters for the considered class of optimization problems. The algorithm is numerically tested for a fictitious cloud of debris in the neighborhood of Sun-synchronous orbits, including cases with multiple chasers

First results of long-term monitoring of Portico Varano in the Camerino Ducal Palace (Italy)

Portico Varano in the Ducal Palace of Camerino (Italy) is a Renaissance monumental quadriporticus that was severely damaged by the Central Italy earthquakes in 2016. Within the field activities for saving cultural heritage foreseen within a recent European research project, a long-term static and dynamic monitoring system was installed in October 2020. Through a series of accelerometers, the monitoring system allows to track the evolution of the modal parameters of the structure, namely frequency, damping ratio and modal shapes, and investigate the effects of environmental conditions on the building dynamics. Furthermore, a series of displacement transducers installed on the vaults of the courtyard allows controlling the evolution of the crack patterns. In this paper, the design and installation of the monitoring system as well as some first results are presented and discussed

Innovative hybrid coupled wall systems to resist seismic action – HYCAD

This article summarizes the research carried out in the ongoing HYCAD project, which aims to improve the performances of a hybrid coupled wall (HCW) system for buildings in seismic areas, by further developing the HCW originally studied in the RFCS project INNO-HYCO. This HCW system consisted of a reinforced concrete (RC) wall coupled with two steel side-columns via steel coupling links. Encouraging outcomes were obtained such as: controlled post-elastic ductile behaviour under medium- and high-intensity earthquakes, suitable lateral stiffness, seismic energy dissipation concentrating in the easily-replaceable steel links and very limited damage in the RC wall. However, advanced studies were required to bring this system into practice, addressing issues and develop advancements in the analysis, design, and detailing. This article summarizes the primary steps taken towards that purpose. Five new components were chosen in order to improve the performance of the HCW system: (1) Link-to-wall connections using post-tensioned tendons; (2) Composite walls with encased steel profiles instead of a conventional RC wall; (3) Rocking coupled wall system; (4) Dissipating devices as links and (5) Precast double slab wall systems. Combining these components, four new HCW systems were developed, pre-designed and analysed through numerical and experimental studies. Advanced yet simple techniques were proposed for the numerical analyses while test specimens are used to characterize local and global behaviour

NHANES newsletter ; Winter 2015-2016

National Health and Nutrition Examination Survey newslette

Assessment of seismic vulnerability of historical defensive walls

This paper presents a study on the behaviour of the walls of the Rocca Roveresca of Senigallia in Italy built in the XIV century on the ruins of a former Roman defensive struc-ture. This is a peculiar example of a small fortress that had undergone in the XV century im-portant modifications of the plant in order to enhance its defensive performances. A linear finite element model is first developed in order to understand the dynamic behaviour of a ge-neric portion of the wall and to detect the probable incipient failure mechanisms. A subse-quent static nonlinear analysis is carried out, with the same finite element model, to investigate the formation of the cracking layout and to detect the position of plastic hinges. The last analysis level is carried out with a tailored macro-element constituted by three bod-ies, namely the two external curtains and the inner fill for which a degradation of the behav-iour is considered. The results obtained demonstrates the efficiency of the wall against earthquakes characterized by return times typical for ultimate limit states. Same issues that deserve further investigation are highlighted