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L'articolo presenta i primi risultati di un ampio progetto di ricerca, che mira a far luce sulla storia economica della provincia di Pavia durante la seconda metà del Novecento, attingendo a una variegata gamma di fonti quantitative e qualitative. In particolare, qui si traccia un quadro quantitativo dei settori secondario e terziario, a partire dai Censimenti dell'Industria e dei Servizi redatti dall'ISTAT con cadenza decennale. Dopo aver illustrato la natura e l'utilità di tale fonte, si analizza in dettaglio una serie di dati statistici utili a ricostruire l'andamento dell'industria e dei servizi su scala provinciale, mettendolo a confronto con la realtà regionale, macroregionale e nazionale. Infine, a titolo d'esempio si accenna ad altre fonti quantitative di carattere locale, delle quali s'intende fare uso sistematico nel prosieguo della ricerca.

L'articolo ricostruisce le vicende che, a cavallo fra gli anni Cinquanta e Sessanta del Novecento, condussero alla fondazione della Facoltà di Economia e Commercio presso l'Università degli Studi Pavia, collocandole nel contesto del cosiddetto "miracolo economico". Dopo aver descritto le pressanti richieste in tal senso provenienti dal tessuto economico provinciale, si illustrano i complessi meccanismi politico-burocratici che videro impegnati fra Pavia e Roma numerosi attori pubblici e privati variamente interessati al successo dell'iniziativa, dalle autorità accademiche agli enti locali, dalle banche pavesi alla Camera di Commercio, dai funzionari ministeriali ad alcune figure politiche nazionali di primo piano.

Ships condition is assessed regularly to maintain safety. Traditionally, structural integrity assessment is performed by surveyors, requiring complex and time-consuming operations to accessany ship...

Although in the last decades the applicable regulations for the design of steel structures have been deeply improved accounting for modern design approaches and technologies, in a few industrial fields, concepts and formulations derived from centuries-old experience are even nowadays the governing rule. This very often limits the potential offered by the technological innovations in high-performance material, such as quenched and tempered (QT) steels. After having verified in the scientific literature, in the commercial one and in several open material databases that some main data necessary to the comprehensive characterization of QT steel used in building large metal structures are lacking, an extensive experimental campaign was undertaken to achieve an updated and specific fatigue strength characterization for certain types of materials. The aim is to overcome the strict requirements of current regulations on the application of both parent QT materials and welded homogeneous and heterogeneous joints between different steel strength. The experimental campaign allowed filling the knowledge gap as well as providing further understanding whether the use of high-strength steel is effective in the improvement of performances of large steel structures, whose fabrication procedures are typical of building sites rather than workshops. Their extensive application in current building practice is expected to be highly beneficial in terms of weight and costs.

To further exploit the potential of marine composites applications in building ship hulls, offshore structures, and marine equipment and components, design approaches should be improved, facing the challenge of a more comprehensive and explicit assessment of appropriately defined limit states. The structure ultimate/limit conditions shall be verified in principle within the whole structural domain and throughout the ship service life. What above calls for extended and reliable materials characterization on the one hand and for accurate and wide-ranging procedures in structural analyses. This paper presents an overview of recent industrial developments of marine composites limit states assessments and design approaches, as available in open literature, focusing on pleasure crafts and yachts as well as navy ships and thus showing a starting point to fill the gap in this respect. After a general introduction about composites characterization techniques, current design practice and rule requirements are briefly summarized. Both inter-ply and intra-ply failure modes and corresponding limit states are then presented along with recently proposed assessment approaches. Three-dimensional aspects in failure modes and manufacturing methods have been identified as the main factors influencing marine composite robustness. Literature review highlighted also fire resistance and hybrid joining techniques as significant issues in the use of marine composites.

Background: L-Arginine is an amino acid which is involved in nitric oxide production regulating vascular tone and cardiovascular homeostasis. Hypertension is one of the most common comorbidities worldwide, and leads to endothelial dysfunction contributing to atherosclerosis, inflammation, and oxidative stress. Frailty is a syndrome of decreased physiological reserves with increased susceptibility to stressors leading to higher mortality, hospitalization, disability, and functional and cognitive impairment. Cognitive impairment is a very common feature in hypertensive frail older adults. Hence, it is very important to treat cognitive impairment to delay and/or prevent adverse events. Our study, thus, investigated the effects of 4-weeks supplementation of L-Arginine on global cognitive function. Methods: We studied 101 frail older patients from April 2020 to April 2021. All subjects were recruited from ASL (local health company of Italian Ministry of Health) Avellino, Italy. All patients fulfilled all of the following inclusion criteria: a previous diagnosis of hypertension, a confirmed frail status, age >65 years. The exclusion criteria were: age Results: We are reporting here the results in 52 patients who hitherto successfully completed the study. The cognitive screening was available at baseline (before treatment) and during a follow-up of 4 weeks. The non-treated group (n=27) had a Montreal Cognitive Assessment (MoCA) score 22.9±0.9 at basal and 23.4±1.0 at follow-up (p=0.06). The treated group (oral L-Arginine, 1.66 g, twice a day; n=25) displayed a MoCA score 23.1±0.7 at basal and 24.2±0.6 at follow-up (p Conclusions: Our data show a significant improvement in the MoCA score in the group treated with L-Arginine. More extensive studies are needed to verify the efficacy of L-Arginine in this population.

In recent years robotics has become an important resource in engineering. Adoption of Robotics and Autonomous Systems (RAS) in activities related to ship inspections has obvious potential advantages, but also arises particular challenges, both from technical and legal viewpoints. The ROBINS project (ROBotics technology for INspection of Ships) is a collaborative project co-funded within the H2020 EU Research and Innovation programme call, aimed at filling the gap between current ship inspections approach and available robotic technology, both from technological and regulatory point of view. Main goal of the present work is to highlight how ship inspections are currently carried out by humans, how they could be improved using RAS, even if not completely autonomous for the time being, at least in selected operational scenarios and how the performances of RAS platforms can be tested to assess their effectiveness in carrying out surveys onboard. In such a framework, a testing facility aimed at assessing RAS’ capabilities as well as providing suitable environment for their development has been built and it is still under development along with dedicated testing protocols, able to assess the equivalence between human and RAS inspection of ship and marine structures. The features of a testing facility where RAS can be tested and the testing protocols are presented, showing how technological and regulatory gaps are filled.

Dock tuning is a crucial stage in the rig service life and in the sailing management. Such operation is necessary for safety and structural stability reasons. The applied pretension has the purpose to increase the stiffness of the whole rig, reducing large displacements caused by aerodynamic and inertial loads. Furthermore, since the rig is aimed at supporting sails, its deformation significantly affects aerodynamic performances, so that dock tuning has also a relevant impact on the propulsion, especially in racing. However, the complexity of the problem and the peculiarities of each different system are the causes of the lack of specific dock tuning procedures in rules and guidelines of Classification societies. The present work, developed in collaboration with the Italian shipyard Perini Navi S.p.A., consists in the validation of a dock tuning numerical procedure adopting a Finite Element Method (FEM) applied to a 67 m long mast. A detailed comparison with real-scale experimental results has been carried out, highlighting the importance of a reliable modelling to accurately predict the non-linear behaviour of the structure. Technical guidelines for dock tuning simulation of large rigs are also provided for the first time in open literature, to the best of the authors’ knowledge.

Monopile foundations contain welding residual stresses and are widely used in industry to support offshore wind turbines (OWTs). The monopiles are subjected to hammering loads during installation and cyclic loads during operation, therefore the influence of residual stress redistribution as a result of fatigue cycles must be evaluated in these structures. The existing empirical models to predict the residual stress redistribution in the presence of cyclic loading conditions are strongly dependent on the material, welding process and loading conditions. Hence, there is a need to predict the residual stress redistribution using finite element simulations. In this study numerical analyses have been conducted to predict the initial state of residual stress in a simplified weld geometry and examine the influence of subsequent cyclic loads on the relaxation behavior in residual stress profiles. The results have shown that fatigue cycles have a severe effect on residual stress relaxation with the greatest reduction in residual stress values observed in the first cycle. Moreover, the numerical prediction results have shown that the stress amplitude plays a key role in the extent of residual stress relaxation in welded structures.

Background Despite primary percutaneous coronary intervention (PPCI) is generally considered the best therapy in older frail adults with ST-segment elevation myocardial infarction (STEMI), the incidence of re-hospitalization for cardiovascular diseases remains significant in these patients. Aims We hypothesized that thrombus aspiration (TA) before PPCI could be a useful treatment for reducing mortality and rehospitalizations in frail patients undergoing PPCI for STEMI. Methods We conducted a study comparing PPCI alone vs TA + PPCI in frail STEMI patients. We examined a cohort of consecutive frail patients aged ≥ 65 years with first STEMI treated with PPCI between February 2008 and July 2015 at the Department of Cardiology of the “Cardarelli” Hospital in Naples, Italy. Results The study was completed by 389 patients (PPCI: 195, TA + PPCI: 194). At 1-month follow-up, the rate of death from any cause was 7.0% in patients treated with PPCI alone vs 3.0% in patients treated with TA + PPCI (p 0.036), whereas death from cardiovascular causes was 6.0% in the PPCI group vs 3.0% in the TA + PPCI group (p 0.028). Equally important, the rate of re-hospitalization due to heart failure was 7.5% in the PPCI group vs 4.0% in TA + PPCI group (p 0.025) and the rate of re-hospitalization due to acute coronary syndrome was 10.0% in the PPCI group vs 4.5% in the TA + PPCI group (p 0.016). Conclusion These results indicate the importance of TA in the treatment of STEMI in a group of high-risk patients such as elderly with frailty.

The aim of this study is to investigate the technical feasibility of an innovative vertical axis floating wind turbine concept with the main focus on the design and verification of the mooring system. The study is developed through iterative processes in order to identify the optimum design for the new floating wind turbine concept. The Ultimate Limit State (ULS) criteria have been considered to verify the integrity of the mooring system in the extreme environmental conditions with a 50-year return period. For this purpose, time domain dynamic analysis has been performed using the commercial software OrcaFlex [Orcina website, OrcaFlex software, https://www.orcina.com/ ]. Although the analysis is carried out for a specific site deemed suitable for the project, the results can be used as an input for any future application in other locations. The present study is intended to be a proof of concept with a proposed scientific framework for optimization of the mooring system which is considered to be a crucial part in the design of floating wind turbines due to their complex dynamic behavior.

BACKGROUND : Admission hyperglycemia is common in subjects with acute myocardial infarction (AMI). Reperfusion therapy with primary percutaneous coronary intervention (PPCI) represents the leading therapeutic choice, in particular in ST-segment elevation myocardial infarction (STEMI). Despite this, mortality, re-hospitalizations and complications remain a relevant problem. Adenosine, a purine nucleoside, may reduce no-reflow. Therefore, we studied the effects of intravenous infusion of adenosine in addition to primary percutaneous coronary intervention (PPCI) in hyperglycemic patients with STEMI. METHODS : We evaluated 836 patients with STEMI and admission hyperglycemia (glycemia > 140 mg/dL). At the end, 399 patients were entered into the database. Patients were grouped on the basis of whether they received adenosine or not. RESULTS : A total of 199 patients received intravenous adenosine infusion and PPCI and 200 patients did not. Kaplan–Meier analysis demonstrated significant differences in all death, cardiac death, re-hospitalization for heart failure and for acute coronary syndrome in the adenosine treated group. CONCLUSIONS : The effects of intravenous infusion of adenosine and PPCI on clinical outcomes are significant but we need future larger studies with larger follow-up and statistical analysis to confirm our results.

Despite several potential advantages, relatively few studies and design support tools have been developed for floating vertical axis wind turbines. Due to the substantial aerodynamics differences, the analyses of vertical axis wind turbine on floating structures cannot be easily extended from what have been already done for horizontal axis wind turbines. Therefore, the main aim of the present work is to compare the dynamic response of the floating offshore wind turbine system adopting two different mooring dynamics approaches. Two versions of the in-house aero-hydro-mooring coupled model of dynamics for floating vertical axis wind turbine (FloVAWT) have been used, employing a mooring quasi-static model, which solves the equations using an energetic approach, and a modified version of floating vertical axis wind turbine, which instead couples with the lumped mass mooring line model MoorDyn. The results, in terms of mooring line tension, fatigue and response in frequency have been obtained and analysed, based on a 5 MW Darrieus type rotor supported by the OC4-DeepCwind semisubmersible.

This paper reports a study on the uncertainties in assessing loading conditions of handy size bulk carriers. Loading conditions and the corresponding hull girder still-water loads are important for the safety of bulk carriers. Unfortunately, statistical studies on this topic remain very few, partly because of the difficulty in fully understanding the impact of loading/unloading operation process and partly because of intrinsic uncertainties in measuring cargo loading conditions data. Three handy-size bulk carriers were investigated and their actual loading conditions, spanning several voyages in 22 months, were collected. Statistical analyses of the collected data resulted in an estimate of the uncertainties in the loading/unloading process. Based on these analyses, probability distribution models for weights in cargo holds, water ballast tanks, fuel tanks as well as consumable tanks are proposed best fitting the collected data; hull girder still water loads statistical distributions are also obtained. It is expected that these analytical models can be used in structural reliability analyses that require the definition of uncertainties of loading conditions and of resulting still water loads.

In an age where sailing boats are losing their reputation of slow-moving vehicles, and where technologies are developing at explosive rhythm, the scantling criteria are deeply changing and naval ar...

In recent years, many disasters due to earthquakes and tsunamis occurred in various countries, including Japan. Two triple junctions exist below the Japanese archipelago and around Japan, where three plates meet to form a complicated crustal structure. To conduct research on the Tohoku earthquake, which accompanied the tsunami that devastated northern Japan in March 2011, Japan Agency for Marine-Earth Science and Technology (JAMSTEC) constructed the scientific deep-sea drilling vessel Chikyu. To understand the mechanism of the earthquakes, a direct access to the fault zone is necessary. During drilling operations, the drill pipes are stressed by different forces and the occurrence of drill-string failures is high, which causes significant loss of money and time. This study focused on the definition of a practical fatigue assessment procedure useful to avoid failures during drilling operations. In this paper the proposed procedure is outlined, and the sensitivity analysis carried out to highlight most influencing parameters is presented.

This paper aims at providing recommendations for the practical application of relatively novel fatigue assessment approaches. Although the concept of notch stress intensity factor (N-SIF) itself was proposed decades ago to provide the analytical solution of the stress field in way of sharp notches, only recently it has been considered as the basis for fatigue strength assessment of welded joints. N-SIF itself and derived quantities such as the equivalent peak stress or the averaged strain energy density (SED) can be assumed as fatigue governing parameters and applied in everyday engineering practice being supported by powerful computation facilities. The N-SIF approach is still too cumbersome for practical applications; the SED approach seems promising to overcome shortcomings, to be applied flexibly to different joint geometries and possibly to automate the calculation procedure in finite element analysis. Software having different features and different refinement strategies are applied in order to benchmark advantages and disadvantages of possible practical solutions for the approaches based on N-SIF and averaged SED, thus offering various element types and modelling strategies. In general, high computational accuracy has been verified, despite relatively coarse meshes, if the element type, shape and mesh pattern is selected properly. However, the approach based on the averaged SED can be unsuitable for studying the notch effect of varying geometries if the averaging area increases more than the local stress concentration rises, as shown for the simplified geometry of a butt joint.

The proper characterization of cast materials is rather challenging because of wide deviations of material features due to the fabrication process. In the frame of propeller design, a recently proposed fatigue assessment procedure highlighted the need of reliable fatigue strength characterization of cast bronzes. With the aim of obtaining reference S–N curves to support the fatigue assessment of propeller blades and to evaluate the effect on fatigue strength of the most influencing parameters, a comprehensive literature survey was carried out. It appeared that fatigue strength of cast bronzes is quite challenging to evaluate, firstly, because the properties may considerably differ from small specimens to real blades and, secondly, because relatively few experimental data are openly available.

Several approaches exist for the fatigue strength assessment of welded joints. In addition to the traditional nominal stress approach, various approaches were developed using a local stress as fatigue parameter. In recent times, the N-SIF based approaches using the notch stress intensity at the weld toe or root have been developed. Based on this, the more practical strain energy density (SED) and the Peak Stress approaches were proposed. This paper reviews the proposed design S–N curves of the N-SIF and SED approaches questioning in particular the consideration of misalignment effects, which should be included on the load side of local approaches in order to consider them individually in different types of welded joints. A re-analysis of fatigue tests evaluated for the effective notch stress approach leads to slight changes of the design S–N curves and of the radius of the control volume used for averaging the SED at the notches. Further, on purpose fatigue tests of artificially notched specimens show that the fatigue assessment using a single-point fatigue parameter might be problematic because the crack propagation phase, being part of the fatigue life, is strongly affected by the stress distribution along the crack path that may vary considerably between different geometries and loading cases.

This paper deals with the estimate of uncertainties affecting still water hull girder loads of bulk and dry cargo ships. In strength assessment of ships, two main categories of acting loads are considered: still water loads and wave induced ones. While the latter are generally defined bearing in mind their stochastic nature, this is not the case for still water loads, which are basically deterministically considered. The underlying assumption is that there is an overall control of the operational profile during the service of a ship. However, this is not the case in actual fact, especially for general dry cargo ships and bulk carriers, since the loading/unloading process cannot be fully controlled by the crew, often resulting into loading conditions rather different from those planned by the designer. Based on an earlier work, where loading conditions of the above-mentioned ship types were statistically analyzed, in the present paper Monte Carlo simulations are used to estimate the uncertainties affecting the hull girder still water loads of ships in service, showing that their allowable values can be exceeded due to inaccuracies in ship and cargo management.

This paper deals with the buckling assessment of stiffened panels, typical of ship and offshore structures. In particular, rather slender structures, involving very thin plates and stiffeners with limited cross section, are considered. In order to limit the computational burden of a fully nonlinear progressive collapse analysis but, at the same time, to retain some benefits of a numerical finite element model assessment, an improved linearized buckling procedure is proposed in this work. The idea is to linearize the computation in a suitable point based on the design load of the structure, so that the results of a linearized buckling analysis are more informative in practice. Results are assessed with nonlinear collapse analyses, comprehensively considering various loading cases. Eventually, a hands-on buckling assessment procedure is suggested, which can be implemented in rules and design process if adequately validated by a suitable number of test cases and, possibly, experimental data.

In this work, the possible exploitation of fiber-reinforced composites in the context of maritime transportation of compressed natural gas (CNG) is investigated. In addition to a more conventional steel configuration, two different fiber materials, carbon and glass, are considered as construction materials for pressure vessels (PVs) to be stored on board ships, with thickness optimized by FEM analysis. The considered scenario is represented by the transportation of CNG from an offshore well to a terminal on shore. Fleets of ships carrying CNG in pressure vessels manufactured with the investigated materials are generated by means of a ship synthesis model (SSM) software and compared on the basis of technical and economical indicators. The choice of the construction material influences considerably the weight of the PVs, which represent a major item of total ship weight and reflects directly on the general transport performances in terms of resistance, seakeeping and reliability in the service. On the other hand, capital as well as operating expenditures are considerably affected by the choice. When exploring the design space, the ship synthesis model is able, at a preliminary stage of the design, to account for the various technical and economical aspects, their implications and relationships. Results are presented of computations carried out in a specific case, identified by the annual gas production and other characteristics of the well terminal and a cruising route for the ships. The comparison is carried out on the basis of the cost per transported unit of gas and of the percentage of success in the transportation process. The computations show that the choice of the PV material has a key influence on the results in terms of optimal number, dimensions and speed of the ships.

This paper deals with the fatigue assessment of three ship structural details. While local approaches, which are proposed in relevant literature and which nowadays are also widely applied i...

The anti-ballistic properties of a new advanced composite armor system have been investigated with the aim to minimize the armor system total weight per unit area. The innovative protection, made of a silicon carbide ceramic outer layer and an inner composite back-packing layer formed by ultra-high molecular weight polyethylene (UHMWPE) fibers, namely $$\hbox {Dyneema}^\circledR $$ Hard Ballistic 26, was realized and then tested performing dedicated ballistic impact tests. In order to investigate its permanent deformation, ceramic cracking, dimension of the rupture, and extension of the impact damage, nondestructive and destructive tests were conducted on the tested panels. The experimental results were used to develop and validate a transient nonlinear dynamic simulation model of the high-velocity impact of a 7.62 AP bullet on the tested armor system. After an accurate setting of the parameters involved in the description of the material constitutive models and of the involved physical phenomena, a complex numerical model was developed in the $$\hbox {ANSYS-Autodyn}^\circledR $$ environment using both mesh and meshless approaches at the same time. The comparison reveals a good agreement between experimental and computational results in terms of ballistic properties, deformations, fragmentation, and fracture of the ballistic armor system. Hence, a new numerical model for the design and the optimization of the ballistic efficiency of composite armor systems was developed and can be now used in current practice.

This paper describes the large-scale testing and the finite element simulations of the collapse of a steel-composite joint, both bolted and bonded. The joined structures are typical ones of shipbuilding and namely of naval ships. Composite superstructures, beside a valuable weight reduction, may improve the signature features of the ship by embedding installed electronic devices into a composite mast. In the frame of a broader research project, including the electromagnetic characterization of the composite structures, also the structural design and its optimization were exploited, embracing, among other issues, the joining solutions between the steel deck structures to the composite ones of the superstructure side shell. A large-scale specimen of the joint was conceived and collapse tested while, in parallel, design simulations were carried out at different levels of detail. Eventually, a complete description of the collapse of the joint, including the nonlinear simulation by finite element analysis of the progressive failure of the composite laminates of the side shell was obtained and test results were used to validate the numerical models. Depending on the design stage, various scantling procedures, from a very simplified one to a rather complex and time-consuming numerical analysis, can now be applied to verify the structural behavior of these steel to composite joints as well as to select the most cost-effective solution among several options.

A Fluid-Structure Interaction (FSI) conventional case study is proposed to be used as a benchmark for numerical analyses. Experimental tests were carried out to provide targets for comparisons; in particular, the study regarded the estimate of the deformed configuration ("flying shape" in the sailing field) of a square sail under a uniform flow regime in a wind tunnel facility. Several tests have been carried out at different wind velocities. The sailcloth has been characterized by means of mono-axial tensile tests obtaining Young's and shear moduli as well as Poisson's coefficients, which have then been used as input parameters for numerical analyses. Test results are considered a benchmark target deserving challenging aspects for numerical simulations in spite of the selected simple test geometry and conditions. Numerical tests have been carried out by means of a commercial software (ADINA™). Analyses used a strongly coupled partitioned approach between a Finite Volume Method (FVM) based on Reynolds Averaged Navier Stokes (RANS) equations, whereas a Finite Element Method (FEM) has been adopted for the structural field. A comparison has been eventually carried out assessing different numerical models. A good overall agreement between experimental and numerical results has been obtained by suitably setting FSI simulation algorithms.

Among recently introduced fatigue assessment approaches, the ones based on the notch stress intensity factor (N-SIF) concept appear to be very promising, both because of their theoretically soundness and because of the possibility of straightforward computation of parameters believed to govern the fatigue process. Actually, while such approaches can be considered in between stress-based approaches and crack propagation ones, quantities like N-SIF and strain energy density in a control volume can be evaluated by finite element analysis according to nowadays well-established procedures, mostly already implemented in commercial FEM software. The present study moves from a former one, dealing with butt joints between typical shipbuilding shell plates, and aims at assessing how the misalignment influences the fatigue strength estimation when applying the strain energy density approach. Eventually, the capabilities of such approach in accounting for misalignments is demonstrated and results are found in agreement with magnification factors currently recommended by guidelines and rules when applying other, stress based, fatigue assessment approaches.

The renewable energy targets set by the EU governments is pushing the wind industry toward deeper and further sites, making the floating option the preferred technical and economic choice. Certification authorities are developing new guidelines, recommended practices and standard specific for this industry, starting to recognize the importance, beside the operational phases, of the temporary phases such as sea transport and installation on site (DNV, 2013). The aim of the present work is to propose an approach to analyse the assembly and temporary phases, namely when the turbine is assembled on the floating support structure and the following transport phase from the shipyard to the operational site. After a review of the approaches for industries near to the offshore wind industry, a framework is proposed where criteria, standards and environmental and loading conditions are discussed. Taking the FOWT NOVA as a case study, the proposed framework is focused on semi-submersible FOWT, assessing the design of this floating support structure, highlighting the impact of these rules and evidencing an overall good performance. The proposed approach can be used as a starting point by administrations and certification authorities and as guidelines in the conceptual/preliminary design phases of the design of an FOWT structure.

Weight saving is crucial in naval architecture to reduce costs and improve performances. In sailing ships design, rig's scantling is important also for ship stability, as rig's weight generates heeling actions on the vessel, due to heeled navigation. Therefore, rig's weight saving remarkably reduces ship's heeling, allowing to increase the wind exposed area, consequently improving the sailing performances. However, because of the complexity of the structure and uncertainties in loading conditions, the structural scantling of a rig implies the adoption of high safety factors. Furthermore, the increasing trend to use composite materials represents an additional source of complexity due to their anisotropic non-homogeneous nature and uncertainties on material properties, and generally implies even larger safety factors, besides implying high construction costs. The present work shows a comparison between an existing 76 m carbon mast and an aluminium alloy one. Suitable FEM models of both rigs were built up and used to assess the structural system strength according to applicable class rules. The cross-section stiffness of the aluminium mast was optimized in order to make masts’ performances comparable. The optimized aluminium mast, of comparable weight of the carbon one, results to be more cost-effective for such range of sailing vessels.

This paper describes the experimental and numerical studies carried out on delaminated fiberglass epoxy resin laminates made-up by different fabrication methods, namely by vacuum infusion and prepreg. While the tested specimens were originally intended for the assessment of buckling behavior of composite laminates of wind turbine blades, results were found valuable for the marine industry as well, because similar laminates are used for the hull shell and stiffeners. Systematic calculations were carried out to assess the effects of an embedded delamination on the buckling load, varying the size and through thickness position of the delamination. Different finite element modeling strategies were considered and validated against the experimental results. The one applying the 9 nodes MITC shell elements was found matching the experimental data despite failure modes were different for the two fabrication methods.

The fatigue assessment of welded ship structures includes high uncertainties. One source of uncertainty is the determination of relevant local stresses. To quantify the uncertainties and to improve the analysis guidelines, round robin studies were performed within the Network of Excellence on Marine Structures (MARSTRUCT) project. One recent study concerned load-carrying fillet welds, which are treated in different ways in structural stress approaches. In total, five partners participated in the work. Two structural configurations of 12 mm thick plates were analysed, that is, double-sided lap joints and doubler plates, each with two different weld throat thicknesses (2.5 mm and 7 mm). Differences in the results were identified and conclusions were drawn with respect to modelling guidelines and typical scatter of computed fatigue lives.

This paper deals with the fatigue strength assessment of attachments of bulb plate stiffeners (Holland profile), typical of ship structures, applying local approaches proposed by the International Institute of Welding (IIW) and in open literature. The application of these methods in the captioned cases is not always straightforward nor sometimes possible, neither effective. Difficulties in following the suggestions of IIW for the finite element (FE) modelling of relatively complex geometries are shown. Basically, the bulb itself is a three-dimensional component interacting with two-dimensional shells surrounding it: the three-dimensional versus two-dimensional mismatch is the main source of complexity. Since a reference thickness of the bulb cannot be identified, even the identification of stress points in post-processing of FE analyses is difficult, often being a cause of scatter and/or disagreement among different approaches. Comparisons among approaches and with available experimental data of tests car...

La percezione delle Guerre d'Italia quale momento topico nel processo di transizione e integrazione geopolitica dell'Europa ha radici storiografiche profonde. Già nella prefazione alla sua "History of the reign of the Emperor Charles V", apparsa nel 1769, William Robertson sosteneva che, tra il 1519 e il 1556, «the powers of Europe were formed into one great political system, in which each took a station, wherein it has since remained with less variation, than could have been expected»; proprio a partire da quel periodo così denso di eventi, «the transactions of every considerable nation in Europe become interesting and instructive to all». Qualche decennio più tardi fu Henry Hallam a indicare nella spedizione italiana di Carlo VIII «the event that first engaged the principal states of Europe in relations of alliance or hostility which may be deduced to the present day» ("View of the State of Europe during the Middle Ages", 1818). Più di recente, alcuni storici hanno in certa misura ripreso tali suggestioni, sottolineando come quelle vicende belliche avessero contribuito a plasmare un sistema di respiro europeo, relativamente più integrato che in precedenza. Questa incipiente trasformazione degli equilibri internazionali, interagendo con le caratteristiche 'strutturali' della società coeva, fece sì che molti attori strategici vedessero nell'accresciuta complessità geopolitica del continente una fonte pressoché inesauribile di allettanti opportunità per acquisire o consolidare potere, prestigio e ricchezza: non ci riferiamo soltanto a chi esercitava la sovranità su ampi aggregati politico-territoriali, più o meno coesi e tendenti all'accentramento, ma anche ai membri dei patriziati cittadini, ai signori feudali e a tutti gli altri soggetti in qualche modo riconducibili a queste élite, in virtù di strategie individuali, familiari e clientelari di vario genere.

In this paper, we report our study on a numerical fluid-structure interaction problem originally presented by Mok et al. (2001) in two dimensions and later studied in three dimensions by Valdes Vazquez (2007), Lombardi (2012), and Trimarchi (2012). We focus on a 3D test case in which we evaluated the sensitivity of several input parameters on the fluid and structural results. In particular, this analysis provides a starting point from which we can look deeper into specific aspects of these simulations and analyze more realistic cases, e.g., in sails design. In this study, using the commercial software ADINA™, we addressed a well-known unsteadiness problem comprising a square box representing the fluid domain with a flexible bottom modeled with structural shell elements. We compared data from previously published work whose authors used the same numerical approach, i.e., a partitioned approach coupling a finite volume solver (for the fluid domain) and a finite element solver (for the solid domain). Specifically, we established several benchmarks and made comparisons with respect to fluid and solid meshes, structural element types, and structural damping, as well as solution algorithms. Moreover, we compared our method with a monolithic finite element solution method. Our comparisons of new and old results provide an outline of best practices for such simulations.

The interest in floating offshore wind turbines (FOWT) has been growing substantially over the last decade and, after a number of prototypes deployed [1], the first offshore floating wind farms have been approved and are being developed. While a number of international research activities have been conducted on the dynamics of offshore floating HAWT systems (e.g. OC3-Phase IV2, OC4-Phase II3), relatively few studies have been conducted on floating VAWT systems, despite their potential advantages [2]. Due to the substantial differences between HAWT and VAWT aerodynamics, the analyses on floating HAWT cannot be extended to floating VAWT systems. The main aim of the present work is to compare the dynamic response of the FOWT system adopting two different mooring dynamics approaches. Two version of the in-house aero-hydro-mooring coupled model of dynamics for VAWT “FloVAWT” [3] are used: one which adopts a mooring quasi-static model, and solves the equations using an energetic approach [4], and a modified version of FloVAWT, which uses instead the lumped-mass mooring line model “MoorDyn” [5]. The floating VAWT system considered is based on a 5MW Darrieus type rotor supported by the OC4-Phase II3 semi-submersible. The results for the considered metocean conditions show that MoorDyn approach estimate larger translational displacements of the platform, compared to the quasi-static rigid approach previously implemented in FloVAWT. As expected, the magnitudes of the forces along the lines are lower, being part of the energy employed for the elastic deformation of the cables. A systematic comparison of the differences between the two approaches is presented.

Ultimate strength of the hull girder of containerships became a significant issue in the last years in view of recent accidents and related investigations. Actually, larger and larger ships were put into service and still are designed and built. Recognizing such an issue, investigations were carried out and led to the issuance of a specific longitudinal strength standard for containerships by the International Association of Classification Societies [1]. Loading conditions become more and more challenging and especially combinations of various actions were found to impair the hull girder ultimate strength. In the attempt to better understand the influence of load combinations onto the ultimate strength of the hull girder, investigations were carried out. In this paper, the effects of the shear is considered using rather refined and accurate finite element models of a typical containership double bottom.

Il volume analizza le molteplici frontiere della Toscana moderna (terrestri e marittime, interne ed esterne, laiche ed ecclesiastiche, economiche e culturali), illustrandone le complesse interazioni e ponendole in stretta correlazione con piů ampi contesti storici e geografici, quali il variegato scacchiere mediterraneo e il sistema imperiale degli Asburgo di Spagna. La costruzione e il controllo dei confini, lungi dall'essere l'esito esclusivo dell'attivitÀ statale, erano profondamente influenzati anche dall'azione di altri attori periferici: emerge in tal modo una struttura del potere piuttosto diffusa nella societÀ e sul territorio, il che peraltro non implica affatto la sottovalutazione del ruolo dello stato. La frontiera appare come una realtÀ ‘vivente', concepita non tanto come una linea continua, ben definita e stabile nel tempo, quanto come uno spazio granulare e discontinuo, sovente frutto di un processo storico lungo e intricato.

Traditionally, propeller design has been focused on all activities necessary to obtain a propeller featuring a high efficiency, avoiding erosive cavitation for given operating conditions and having adequate structural strength. In recent years, more and more challenging requirements have been imposed, such as the reduction of radiated noise and pressures pulses, requiring more precise analyses and methods in the optimization of the propeller performance. On the other hand, the evaluation of the propeller strength still relies on simplified methods, which basically consider the blade as a cantilever beam subjected to characteristic static forces. Since the loads acting on a blade are variable in the blade revolution and in different operating conditions throughout the ship life, a procedure to account for the influence of fatigue phenomena is proposed. The fatigue assessment could reduce the safety factor in the propeller scantling rules and allow improving the quality of propeller design (e.g. obtaining higher efficiency, margin on cavitation phenomena, less noise).