Influence of Fatigue on Cable Arrangement in Cable-stayed Bridges

A. Pipinato,C. Pellegrino,G. Fregno,C. Modena 한국강구조학회 2012 International Journal of Steel Structures Vol.12 No.1

Cable arrangement in cable-stayed bridges is one of the key issues in optimizing the design of this typology of bridges. Oscillating axial forces in the cables due to vehicular loading is usually the parameter on which attention of the designer is focused. The cables are particularly vulnerable to fatigue phenomena but the variation of axial forces in hangers depending on load configuration and cable arrangement was not deeply studied despite the fact that it is an important parameter in relation to the fatigue behaviour of the overall bridge. In this context, this paper mainly deals with the influence of fatigue on cable arrangement in cable-stayed bridges. The analysis is carried out by performing moving load analysis along the deck, and a parametric analysis of cable arrangement. Moreover, a lifetime assessment considering different corrosion propagation in cables is shown.

Linear Elastic Behavior of Circular Holed Steel Box Sections Under Compression

Emanuele Maiorana,Carlo Pellegrino 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.3

The aim of this work is to provide insights into the linear elastic behavior of steel box sections with centered and eccentric holes, placed at various points on the sides and at the corners of sections, and subjected to uniform compression. The infl uence of the following parameters was observed on stability, mainly through critical deformed shapes: (a) ratio of section aspects, (b) length-to-width ratio, (c) slenderness of sides, (d) diameter of holes, (e) coordinates x and y of the position of the hole on one side of the box section. Indications regarding important design aspects are given: (a) the best location for a single hole, or several holes, in cross-section; (b) the eff ects of circular holes with small, medium and large diameters on the linear buckling factor; (c) the eff ect of symmetric and eccentric holes for purposes of stability; (d) the best performing transversal section for square to rectangular holed box sections, in terms of stability; (e) critical slenderness values at which transition occurs from ultimate strength collapse of stocky box sections and critical elastic stress of slender ones.

Elasto-plastic behaviour of perforated steel plates subjected to compression and bending

Emanuele Maiorana,Carlo Pellegrino,Claudio Modena 국제구조공학회 2011 Steel and Composite Structures, An International J Vol.11 No.2

The aim of this work is to provide some insights into the elasto-plastic behaviour of plate girder web square and rectangular panels with centred and eccentric holes under both compression and in-plane bending moment. The numerical study was validated comparing the numerical results obtained for one simple steel plate configuration with the corresponding experimental results, obtained at the University of Padova, observing the influence of the initial out-of-plane imperfections on the force vs. displacement relationship and ultimate strength. Once validated the numerical approach, the effect of bending moment on the stability of the plate is studied and some differences with respect to the uniform compression load case are shown. The influence of dimension and position of the hole, the plate aspect ratio and the steel grade on elasto-plastic behaviour is observed. Some indications regarding the critical slenderness (at which transition from elastic to plastic collapse occurs) are given for square and rectangular plates with symmetric and eccentric holes having small, medium and large diameter.

Linear buckling analysis of welded girder webs with variable thickness

Emanuele Maiorana,Carlo Pellegrino 국제구조공학회 2011 Steel and Composite Structures, An International J Vol.11 No.6

Steel girder web panels have been subjected in recent decades, to a number of experimental and numerical studies but the mechanisms that regulate the behaviour of the panels composed by two subpanels with different thickness were not deeply studied. Furthermore specific design rules regarding the estimation of the buckling coefficient for panels with variable thickness are not included in the codes even if this is a common situation particularly for steel bridge girders with beams having significant height. In this framework,this work aims to investigate buckling behaviour of steel beams with webs composed of panels with different thicknesses subjected to both in-plane axial compression and bending moment and gives some simplified equations for the estimation of the buckling coefficient.

Robotic Intraoperative Tracheobronchial Repair during Minimally Invasive 3-Stage Esophagectomy

Alessandra Marano,Silvia Palagi,Luca Pellegrino,Felice Borghi 대한흉부외과학회 2021 Journal of Chest Surgery (J Chest Surg) Vol.54 No.2

Tracheobronchial injury (TBI) is an uncommon but potentially fatal event. Iatrogenic le- sions during bronchoscopy, endotracheal intubation, or thoracic surgery are considered the most common causes of TBI. When TBI is detected during surgery, concomitant sur- gical treatment is recommended. Herein we present a case of successful robotic primary repair of iatrogenic tracheal and left bronchial branch tears during a robot-assisted hybrid 3-stage esophagectomy after neoadjuvant chemoradiotherapy. A robotic approach can facilitate the repair of this injury while reducing both the potential risk of conversion to open surgery and the associated increased risk of postoperative respiratory complications.

A Review of the Fatigue Strength of Shear Bolted Connections

Paolo Zampieri,Andrea Curtarello,Emanuele Maiorana,Carlo Pellegrino 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.4

Steel bolted connections are the typical joints used in civil engineering but also in the fi eld of mechanical engineering. In particular, slip-resistant bolted connections are those most used in bridge construction. In these applications, bolted joints are subjected to a cyclic load that arises from traffi c fl ow. It is well known that joints are the critical components of constructions subjected to cyclic loads, due to stress concentration that causes fatigue crack initiation. The purpose of this paper is to provide a summary of considerations, from principal scientifi c studies of fatigue strength and the behaviour of bolted joints, as well as an up-to-date comprehensive assessment for future development. In particular, a discussion is proposed regarding the parameters that infl uence the fatigue of bolted joints. The paper concludes with a summary of the major results reported in terms of S–N curves.

Systematic Bench‐Scale Assessment of Perchlorate (ClO 4 − ) Rejection Mechanisms by Nanofiltration and Ultrafiltration Membranes

Yoon, Yeomin,Amy, Gary,Cho, Jaeweon,Pellegrino, John Taylor Francis 2005 Separation science and technology Vol.39 No.9

<P>Measurements of the rejection of perchlorate anion (ClO 4 − ) have been performed by using two thin‐film composite nanofiltration (NF) membranes and four ultrafiltration (UF) membranes. The latter four membranes are all from the same manufacturer and, ostensibly, from the same material family. These were chosen to systematically change the membranes steric properties, while keeping the same material chemistry, thus, the enthalpic interactions should stay constant. The perchlorate anion (at a concentration of 100 g/L of ClO 4 − by “spiking” with KClO 4 ) was presented to the membrane as a pure component, in binary mixtures with other salts, and at varying pH and ionic strength (conductivity). Also, a natural source water was “spiked” with perchlorate anion and used to document the effects of a complex mixture, including natural organic matter, on the observed rejection. All filtration measurements were performed at approximately the same permeate flow rate to minimize artifacts from mass transfer at the membrane interface. In general, the results indicate that, in a pure component system, target ions (in this case ClO 4 − ) can be significantly excluded from like‐charged membranes with pores large with respect to the size of the ion, but this rejection capability decreases in the presence of a sufficient amount of other ions that can screen the electrostatic force field.</P>

Transmission Fiber Chromatic Dispersion Dependence on Temperature: Implications on 40 Gb/s Performance

Paulo S. André,Ant?io L. Teixeira,Armando N. Pinto,Lara P. Pellegrino,Berta B. Neto,J?e F Rocha,Jo? L. Pinto,Paulo N. Monteiro 한국전자통신연구원 2006 ETRI Journal Vol.28 No.2

In this letter, we will evaluate the performance degradation of a 40 km high-speed (40 Gb/s) optical system, induced by optical fiber variations of the chromatic dispersion induced by temperature changes. The chromatic dispersion temperature sensitivity will be estimated based on the signal quality parameters.

A Randomized Open-Label Trial to Assess the Effect of Plant Sterols Associated with Ezetimibe in Low-Density Lipoprotein Levels in Patients with Coronary Artery Disease on Statin Therapy

Gisane Biacchi Gomes,Ana Denise Zazula,Leonardo Seidi Shigueoka,Rosangela Alquieri Fedato,Ana Beatriz Brenner Affonso da Costa,Luiz Cesar Guarita-Souza,Cristina Pellegrino Baena,Marcia Olandoski,Jose´ 한국식품영양과학회 2017 Journal of medicinal food Vol.20 No.1

Consumption of food products enriched with plant sterols and the use of ezetimibe reduce cholesterol absorption in the intestine and effectively reduce low-density lipoprotein (LDL) plasma levels. We evaluated the therapeutic effect of the ezetimibe+plant sterol association in patients with coronary artery disease still not reaching recommended lipid levels despite the use of statins. We performed a prospective open-label study with 41 patients with stable coronary disease and LDL >70 mg/dL. Patients were randomized into four groups for a 6-week treatment: the control (CT) group remained on the same statin therapy, the ezetimibe (EZ) group received 10 mg/day of ezetimibe, the plant sterol (PS) group received spread enriched with 2 g of plant sterols, and the ezetimibe+PS (EZ+PS) group received 10 mg/day EZ +2 g PS. Initial mean LDL level was 97.4 ± 31.1 mg/dL in control group, 105.1 ± 23.1 mg/dL in EZ group, 95.4 ± 27.7 mg/dL in PS group, and 97.0 ± 8.3 mg/dL in EZ+PS group (P > .05). After 6 weeks of treatment, LDL of patients slightly increased in the control group (+8.9%; P > .05) and dropped in EZ group (-19.1%; P = .06), PS group (-16.6%; P = .01), and EZ+PS group (-27.3%; P < .01). Mean LDL levels after treatment were 70.5 – 17.9 mg/dL in EZ+PS group, lower than the other groups (control was 106.1 ± 34.9 mg/dL, EZ group was 85.0 ± 35.6 mg/dL, and PS was 79.6 ± 29.7 mg/dL) (P = .05 variance analysis factor [ANOVA]). Body weight, body–mass index, and glucose plasma levels did not change significantly after intervention. The combination of PS+ezetimibe was associated with lower LDL levels and suggests beneficial therapeutic effect against major cardiovascular events.