Search results for " costruzione"
showing 10 items of 481 documents
Ottimizzazione di un freno a fluido magnetoreologico per uso automobilistico
2009
Il presente lavoro ha come oggetto lo studio numerico di un freno a fluido magnetoreologico (MR) per uso automobilistico tramite il codice agli elementi finiti ANSYS. In seguito ad un dimensionamento analitico preliminare del freno la realizzazione di un modello FEM magnetico permette un’accurata valutazione della distribuzione del campo magnetico nel fluido MR e la valutazione del momento frenante generato in seguito all’applicazione della corrente alla bobina. La successiva ottimizzazione in due fasi del circuito magnetico consente di migliorarne le prestazioni in termini di momento frenante e peso del dispositivo. L’analisi FEM termica di tipo dinamico permette infine di valutare l’andam…
DESIGN AND OPTIMIZATION OF A CHASSIS FOR A FORMULA SAE RACE CAR
2009
In this paper, the design process of a new chassis for a Formula SAE car is presented. The chassis is undoubtedly one of the most important parts of the car, both for the influence that it has on the vehicle dynamic behaviour, and because it is the main component that assures the driver safety. The new designed chassis is composed of many structural tubular bars and has been equipped with systems for the joining of all the auxiliary members. After the definition of the masses distribution and the choice of the main dimensions, preliminary CAD and FEM models have been carried out for the evaluation of the structural behaviour of this kind of vehicle. Successively, in order maximizing the tor…
Influence on the Dynamic Behavior of Full Car Equipped by Magnetorheological Damper via Switch on/off and h∞ Controller
2011
This paper shows the influence on dynamic behavior of the car when it is equipped with magneto-rheological dampers controlled by a feedback. The feedback is built up in two ways; the first is implemented by a switch on/off control that is characterized by the injection of magnetic field with a constant value. It happens when a certain value of relative speed between the sprung and unsprung mass is exceeded. The second feedback is characterized by the H-infinity control which is based on the relative displacement in order to vary the magnetic field signal in a continuous manner. At the same time the H-infinity control of vehicle is maintained by taking into account the exceeding of speed sig…
On the Use of Two Emerging Laser-Based Flaw-Detection Techniques – Considerations and Practicalities
2023
The pursuit of non-contact techniques for detecting ultrasonic waves propagating on the surface of solids is stimulated by the possibility of gaining some advantages over conventional contact methods. Non-contact methods are becoming a milestone in performing non-destructive evaluation in several industrial fields, where hazardous environments, narrow spaces, high temperatures, and complex geometries are encountered. Such methods exploit photo-acoustic interactions between light and sound waves. This work compares two non-contact laser-based methods for detecting artificial flaws of different sizes in metallic specimens. It uses multi-signal homodyne interferometry and single beam deflectom…
Prediction of driving performance of a hybrid vehicle with CVT transmission
2009
The purpose of this work is the description of the phenomenology of driving behaviour of a production car characterized by a hybrid powertrain and a continuously variable transmission (CVT), along with a theoretical study of consumption that provides results in agreement with the experimental ones obtained and reported by the Car Maker.
Implementation of a fast and low cost IR-NDT technique by means of a Square Pulse modulated Lock-In Thermography
2012
This work describes the development of an IR-NDT procedure based on a lock-in signal treatment in the frequency domain to obtain phase-contrast defect signatures. Heat stimulation is obtained by periodically shattering a common low-power halogen lamp. The delivered heat is then modulated as a train of square waves with multi-frequency harmonic content. The proposed lock-in algorithm is able to selectively retrieve phase and amplitude information at various frequencies of the acquired temperature, acting also as a narrow band filter to improve defect-signature to noise ratio. The procedure is implemented and evaluated by means of low cost IR equipment to investigate artificially defected thi…
IMPLEMENTAZIONE DI TECNICHE NDT DI TERMOGRAFIA AD INFRAROSSI SU PANNELLI IN COMPOSITO GRP PER APPLICAZIONI NAUTICHE
2010
Il presente lavoro descrive l’implementazione di due tecniche di termografia attiva ad infrarossi per il controllo non distruttivo (IRNDT) di delaminazioni sub-superficiali su pannelli in composito (GRP) di grosso spessore, tipicamente impiegati per uso navale. Si è in particolare fatto uso di attrezzature a basso costo consistenti in comuni lampade alogene a bassa potenza come sorgenti di calore esterne, ed una termocamera ad infrarossi a singolo sensore a bassa risoluzione termica e basso frame rate. Le due tecniche implementate sono la Pulsed Thermography (PT) ed una nuova variante di Lock-In Thermography denominata Pulse-Modulated Lock-In Thermography (PMLT), basata sull’analisi in freq…
Robotic non-destructive inspection
2012
Automation of non-destructive testing (NDT) of engineering components and structures represents one of the strategic objectives of many industries. It enables increases in accuracy, precision and speed of inspection while reducing production time and associated labour costs in contrast to manual inspection. The use of robots can provide additional flexibility and autonomy to automated NDT. Automated robotic inspection can be beneficial in diverse industrial scenarios ranging from integration of NDT into the manufacturing process of components with very complex geometry, such as gears, to periodical in-service overhaul of large structures (for instance, in petrochemical and aerospace industr…
The effect of the through-the-thickness compressive stress on mode II interlaminar fracture toughness
2017
The effect of through-the-thickness compressive stress on the mode II interlaminar fracture toughness is investigated experimentally and replicated numerically. The modified Transverse Crack Tensile specimen recently proposed by the authors is used, together with an experimental device designed to apply a constant transverse compressive stress on the surface of the specimen. Experiments are conducted using IM7/8552 specimens for different compressive stresses, ranging from 0 to 100 MPa, covering all the practical applications commonly encountered in the aeronautical industry (e.g., tightened filled holes or bolted joints). It is shown that the mode II interlaminar fracture toughness increas…