GAIOTTI M.

For naval ships, shock phenomena caused by underwater explosions are demanding limit states not only for machinery and equipment, but also for their foundation structures. Being a crucial part of the system integration, their shock resistance is normally verified by means of dedicated calculations as it is in general not possible the testing of...

Merchant vessels experience regular structural assessments. Traditionally, surveys are performed physically by surveyors being expansive and time-consuming. Imagery based, cracks recognition is a topic obtaining considerable interest in commercial and scientific sectors. By using computer vision algorithms, authors propose a new approach to...

Hull weight is a design parameter affecting the whole performances of a ship, being related to building costs, operational costs, maintenance and durability, and not least to satisfaction of functional requirements. Naval ships are no exception and impact of hull weight is crucial to fulfil mission requirements. In the light of the above,...

In this paper, a semi-automatic design procedure for concept and preliminary phases of hull structural design is described. It allows investigating the design of ship structures, consisting of a series of stiffened panels surrounded by primary members, assembled to form the hull girder. The optimal configuration of the structural layout and the...

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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...

In various fields of industrial engineering, including naval architecture, structural design is considered one of the most challenging steps by designers as it shall accommodate all other design aspects, likely already defined in earlier steps. Moreover, structures need to comply with specific requirements, i.e. limit states, while also...

In this study, the cumulative process of buckling deformation is evaluated for a stiffened panel sub jected to uniaxial cyclic loading. The impact of cyclic loading on the ultimate strength of the panel is then estimated. It is noted that the arising of permanent deflection could be simulated by finite element method analysis using a suitable...

In this study, the cumulative buckling deformation process is evaluated for a stiffened panel subjected to two different uniaxial cyclic loading conditions, namely compressive loading only and alternating tensile-compressive loading. The impact of the cyclic load on the ultimate strength of the panel is then estimated. It should be noted that...

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 space. Imagery based, three-dimensional (3D) reconstruction of structures is a new area obtaining considerable interest. It can provide low-cost,...

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...

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,...

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...

Composite materials are becoming more and more popular, even for large ship and offshore structures. They offer lightweight and adaptable strength and stiffness properties. In case of slender structures, where buckling is the governing limit state, such features are valuable and allow designing high performance assemblies like racing crafts as...

Even if the non-contact underwater explosion phenomenon has been studied for decades and various numerical methods have been provided in open literature, its effects on naval structures, especially those made by composite materials, are, even nowadays, a matter of research. Actually, a fully coupled fluid-structure interaction model for...

Despite the underwater explosion phenomena (UNDEX) have been studied for decades and several numerical methods have been proposed in literature, the simulation of the whole phenomenon in issue is even nowadays a matter of research. In this paper, a Volume of Fluid (VOF) approach, which allows the simulation of Fluid-Structure Interaction (FSI),...

Hull weight is a main structural concern in pleasure craft design, being in such project the maximum speed one of the most important contractual limits imposed by owner to shipyards. This is particularly true for composite structures, where the structural layouts and the beams' dimensions may vary significantly among very similar projects,...

Non-contact underwater explosions (UNDEX) can cause extremely large deformations on naval composite structures related to heavily nonlinear phenomena. For this reason, for military purposes, used materials must have excellent shock resistance properties. Historically, the underwater shock transient effects on fiberglass laminates are predicted...

The paper presents the calibration of a numerical collapse model of unidirectional fiberglass epoxy panels with an initially embedded delamination. The panels were tested under axial compression, able to induce buckling collapse. The penalty stiffness, the strength and the fracture toughness are the key parameters governing the...

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)...

Ship surveys are hazardous and expensive tasks as long as they are carried out by human surveyors to a large extent. The adoption of robotic means can enhance safety by replacing some human operations, filling the gap between the current approach and available robotic technologies, even from a regulatory point of view.The ROBINS project...

Si descrive lo sviluppo della testing facility costruita presso i laboratori dell'università di Genova nell'ambito del progetto europeo H2020 Robotic Technologies for the Inspection of Ships (ROBINS)