Search results for ":Mechanical engineering [Engineering and technology]"
showing 10 items of 51 documents
Studio delle prestazioni di giunzioni incollate ibride (Strength evaluation of structural hybrid bonded joints)
2013
The idea of “hybrid joints” arises from the need of joining together materials, producing a tough, stiff and lightweight joint. The core concept is: use two different joining techniques, with the aim to increase the strength and gather the advantages of each technique, reducing the drawbacks. In this work hybrid joints consist in joints produced with two different kinds of joining techniques: one of them being adhesive bonding and the other being one among Resistance Spot Welding, Pop Riveting, Clinching, Self Piercing Riveting. The performance of hybrid joints are compared with those of traditional joints for the single lap joint geometry, for different geometric (plates thickness, pitch o…
Thermal stress analysis of different full and ventilated disc brakes
2015
During the braking phase, the heat produced by friction between pads and disc cannot be entirely dissipated. Consequently, the brake disc, especially if very hard braking occur, can accumulate large amounts of heat in a short time so producing high gradients of temperature on it. Under these conditions, functionality and safety of the brake system can be compromised. The object of this study is to investigate, under extreme working conditions, the thermomechanical behaviour of different brake rotors in order to evaluate their efficiency and stability and to identify any compromising weakness on them. In particular, by means of FEM thermo-mechanical coupled analyses, one full disc and three …
Fatigue methodology for life predictions for the wheel-rail contact area in large offshore turret bearings
2016
The present report presents a fatigue life prediction method for large roller bearings applied in the turret turn table for large loading buoy units. The contact points between wheel and rail in these bearings are subjected to a multi-axial fluctuating stress situation and both surface wear and fatigue cracking may occur. A methodology based on the Dang Van fatigue criterion is adopted. The criterion is based on an equivalent stress defined as a combination of the fluctuation of the shear stress from its mean value at a critical plane and the associated hydrostatic stress at the given time. The present work is supporting the theoretical model by extensive laboratory testing. Both full scale…
Behaviour of a speargun with a novel muzzle - Comportamento di un fucile subacqueo con testata innovativa
2013
The paper presents the results of a numerical and experimental investigation performed on a barrel of a speargun equipped with two kinds of muzzle. In particular, a standard muzzle for speargun (having an elastic propulsion) has been compared with an innovative one called ‘roller’. This new muzzle is equipped with two rollers and special bands. The rubber bands, fixed at the lower side of the barrel, run through the rollers and are engaged in suitable seats of the shaft. These bands are, therefore, longer than the traditional ones and, consequently, with equal force applied by the diver, the roller speargun has a longer range. Thanks to the particular geometry of the new muzzle, one of the …
Behaviour of a speargun with a novel muzzle
2013
The paper presents the results of a numerical and experimental investigation performed on a barrel of a speargun equipped with two kinds of muzzle. In particular, a standard muzzle for speargun (having an elastic propulsion) has been compared with an innovative one called ‘roller’. This new muzzle is equipped with two rollers and special bands. The rubber bands, fixed at the lower side of the barrel, run through the rollers and are engaged in suitable seats of the shaft. These bands are, therefore, longer than the traditional ones and, consequently, with equal force applied by the diver, the roller speargun has a longer range. Thanks to the particular geometry of the new muzzle, one of the …
Good Old-Fashioned Artificial Consciousness and the Intermediate Level Fallacy
2018
Recently, there has been considerable interest and effort to the possibility to design and implement conscious robots, i.e., the chance that a robot may have subjective experiences. However, typical approaches as the global workspace, information integration, enaction, cognitive mechanisms, embodiment, i.e., the Good Old-Fashioned Artificial Consciousness, henceforth, GOFAC, share the same conceptual framework. In this paper, we discuss GOFAC's basic tenets and their implication for AI and Robotics. In particular, we point out the intermediate level fallacy as the central issue affecting GOFAC. Finally, we outline a possible alternative conceptual framework towards robot consciousness.
A PARAMETERS’ SYNTHESIS OF GRINDING PROCESS MODELING FOR CARBIDE DRILLS DEEP HOLES AND SMALL DIAMETER
2013
Studio delle prestazioni di giunzioni incollate ibride
2011
Le giunzioni ibride sono giunzioni in cui coesistono due differenti tipologie di giunzione, di cui una è l’incollaggio. L’articolo mostra i risultati di una campagna sperimentale volta a caratterizzare le prestazioni di giunti incollati ibridi in confronto ad alcune tipologie di giunzioni tradizionali. Si sono prese in considerazioni come tecnologie di giunzione tradizionali la saldatura a resistenza, la rivettatura a strappo, la clinciatura e la rivettatura auto perforante. In particolare si sono studiate le prestazioni di giunti a semplice sovrapposizione per differenti condizioni geometriche del giunto (spessore aderendi, passo tra i punti di fissaggio meccanico) e condizioni ambientali …
On relation between J-integral and heat energy dissipation at the crack tip in stainless steel specimens
2019
In this paper, an experimental procedure to evaluate the elastic-plastic J-integral at the tip of a fatigue crack is presented. According to this new approach, the elastic component of the J-integral is derived from Thermoelastic Stress Analysis, while the plastic component of the J-integral is derived from the heat energy loss. An analytical link is proposed to apply this new experimental technique. Therefore, the elastic-plastic J-integral range was evaluated starting from infrared temperature maps measured in situ during crack propagation tests of AISI 304L stainless steel specimens. It was found that the range of the infrared thermography-based J-integral correlated well the crack growt…
Editorial: Consciousness in Humanoid Robots
2019
Building a conscious robot is a grand scientific and technological challenge. Debates about the possibility of conscious robots and the related positive outcomes and hazards for human beings are today no longer confined to philosophical circles.